Academic literature on the topic 'Plants Disease and pest resistance'
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Journal articles on the topic "Plants Disease and pest resistance"
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YOSHIHARA, Teruhiko. "Disease and pest resistance of plants." Journal of the agricultural chemical society of Japan 62, no. 6 (1988): 995–97. http://dx.doi.org/10.1271/nogeikagaku1924.62.995.
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DEMPSEY, D., H. SILVA, and D. KLESSIG. "Engineering disease and pest resistance in plants." Trends in Microbiology 6, no. 2 (February 1998): 54–61. http://dx.doi.org/10.1016/s0966-842x(97)01186-4.
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DHALIWAL, Harcharan S., and Hirofumi UCHIMIYA. "Genetic Engineering for Disease and Pest Resistance in Plants." Plant Biotechnology 16, no. 4 (1999): 255–61. http://dx.doi.org/10.5511/plantbiotechnology.16.255.
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Rajareddy, Gundreddy, Gunturi Alekhya, Kirankumar Reddy Kasa, Gopal Dasari, Kalwala Srikanth Reddy, and Kadapa Sreenivasa Reddy. "Nutrient Strategies for Pest Resilience in Plants: A Review." International Journal of Environment and Climate Change 14, no. 5 (May 22, 2024): 279–91. http://dx.doi.org/10.9734/ijecc/2024/v14i54188.
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Sustainable agriculture plays a vital role in modern farming, addressing concerns of traditional pesticides, which raise issues related to safety, environmental impact, and resistance. Consequently, alternative insect pest management methods, including nutrient-based approaches, have gained prominence. However, understanding the relationship between nutrients and plant diseases remains a complex challenge. This review synthesizes recent insights on the impact of specific nutrients (N, P, K, Mn, Zn, B, Cl and Si) on insect pest resistance in sustainable agriculture. Nitrogen supply has a major impact on insect pest intensity as compared to low nitrogen doses and control, pest populations were high at high levels. Phosphorus (P) has an inconsistent role in resistance. Comprehensive nutrient management in sustainable agriculture offers cost-effective, eco-friendly disease control, reducing pesticide reliance. Potassium (K) enhances resistance to an optimal point, beyond which there is no further improvement. Proper nutrient management can make subsequent control measures more efficient and economical. Understanding the interplay of plant nutrition, insect herbivores, and community dynamics is essential. Balanced nutrient levels, especially potassium and phosphorus, indirectly strengthen plant resistance to various insect pests through biochemical, physical, and mechanical mechanisms. Strategies to enhance plant defense against phytophagous insects align with the demand for food and nutritional security. This review emphasizes the significance of comprehensive nutrient management in sustainable agriculture for disease and pest control while prioritizing food safety and environmental quality.
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Starratt, Alvin N., and George Lazarovits. "Increases in Free Amino Acid Levels in Tomato Plants Accompanying Herbicide-Induced Disease Resistance." Pesticide Biochemistry and Physiology 54, no. 3 (March 1996): 230–40. http://dx.doi.org/10.1006/pest.1996.0027.
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James, D. J., A. J. Passey, M. A. Easterbrook, M. G. Solomon, and D. J. Barbara. "Transgenes for Pest and Disease Resistance." Phytoparasitica 20, S1 (March 1992): S83—S87. http://dx.doi.org/10.1007/bf02980414.
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Ghosh, Paramita, Anjanabha Bhattacharya, and Bharat Char. "Manipulating disease and pest resistance pathways in plants for enhanced crop improvement." Bioscience Biotechnology Research Communications 10, no. 4 (December 25, 2017): 631–44. http://dx.doi.org/10.21786/bbrc/10.4/5.
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Amtmann, Anna, Stephanie Troufflard, and Patrick Armengaud. "The effect of potassium nutrition on pest and disease resistance in plants." Physiologia Plantarum 133, no. 4 (August 2008): 682–91. http://dx.doi.org/10.1111/j.1399-3054.2008.01075.x.
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Yin, Kangquan, and Jin-Long Qiu. "Genome editing for plant disease resistance: applications and perspectives." Philosophical Transactions of the Royal Society B: Biological Sciences 374, no. 1767 (January 14, 2019): 20180322. http://dx.doi.org/10.1098/rstb.2018.0322.
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Diseases severely affect crop yield and quality, thereby threatening global food security. Genetic improvement of plant disease resistance is essential for sustainable agriculture. Genome editing has been revolutionizing plant biology and biotechnology by enabling precise, targeted genome modifications. Editing provides new methods for genetic improvement of plant disease resistance and accelerates resistance breeding. Here, we first summarize the challenges for breeding resistant crops. Next, we focus on applications of genome editing technology in generating plants with resistance to bacterial, fungal and viral diseases. Finally, we discuss the potential of genome editing for breeding crops that present novel disease resistance in the future. This article is part of the theme issue ‘Biotic signalling sheds light on smart pest management’.
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Ajaharuddin, SK MD, Madan Lal, Ashwani Yadav, Nitin Kumar, Atul Dhakad, Gayatri Sinha, Budhesh Pratap Singh, and Archana Upadhyay. "Breeding for Resistance against Pest and Diseases in Tomatoes: A Review." Journal of Scientific Research and Reports 30, no. 6 (May 13, 2024): 469–79. http://dx.doi.org/10.9734/jsrr/2024/v30i62063.
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Diseases and pests have a substantial effect on tomato production, greatly affecting both the quantity and quality of this crucial vegetable crop. Although fungicides and insecticides have been important in controlling plant diseases and pests, their excessive usage raises significant environmental issues. Vegetable breeders are increasingly concentrating on developing cultivars with natural tolerance to biotic stresses to promote sustainability and environmental friendliness. The change in focus is intended to cultivate tomato cultivars with inherent resistance to diseases and pests, hence decreasing the need for chemical treatments. Advancements in creating high-yielding genetically resistant tomato cultivars are a result of detailed study on the genetic basis of pest and disease resistance in tomato crops, as well as the complex interactions between the host plant and pathogens. For effective breeding programs and pre-breeding activities, scientists and breeders must have access to sources of resistance and a thorough grasp of the genetic complexities involved. This requires examining the genetic composition of both the tomato plants and the different infections that are impacting them. Breeders may generate tomato cultivars with strong resistance to common diseases and pests by using the inherent defensive mechanisms found in certain tomato types via selective crossing. Continuing to study how hosts and pathogens interact and the molecular processes involved in resistance is crucial. This information offers vital insights on how to improve and expand resistance, leading to the creation of cultivars with long-lasting and wide-ranging resistance. Currently, the emphasis on breeding is a proactive and sustainable strategy for transfer of resistances in high yielding tomato cultivars. Researchers aim to develop tomato cultivars that provide high yield and demonstrate tolerance to changing disease and pest stresses by integrating genetic knowledge with sophisticated breeding methods. This comprehensive method protects tomato crops and encourages environmental sustainability by decreasing the need on chemical inputs in agriculture.
Dissertations / Theses on the topic "Plants Disease and pest resistance"
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Melander, Margareta. "Transgenic resistance to pathogens and pests /." Alnarp : Dept. of Crop Science, Swedish Univ. of Agricultural Sciences, 2004. http://epsilon.slu.se/a496.pdf.
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Geddes, Jennifer M. H., and University of Lethbridge Faculty of Arts and Science. "Fusarium head blight of barley : resistance evaluation and identification of resistance mechanisms." Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 2006, 2006. http://hdl.handle.net/10133/399.
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An evaluation of nineteen barley lines using three artificial inoculation methods concluded that spray inoculation was the most reproducible method and provided the greatest discrimination of resistance. Six of the nineteen barley lines were used for proteomic studies to identify defense responses following F. graminearum infection. All lines responded by inducing an oxidative burst and pathogenesis-related proteins. Differences in response magnitude and the proteins activated could be attributed to varying levels of FHB resistance amongst the barley lines. RNA microarray profiling and iTRAQ technology were used to study the interaction between two barley lines under five different treatments testing the effect of the fungus, trichothecene, and their interaction. Resistance was differentiated by the early induction of defense-related genes and the activation of the JA and ethylene defense pathways in Chevron, compared to the induction of a less efficient defense pathway in Stander; observed intra- and inter-cultivar differential responses are discussed.xvii, 196 leaves : ill. ; 29 cm.
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Soriano, Imelda Rizalina. "Novel inducible phytochemical defences against plant parasitic nematodes /." Title page, table of contents and summary only, 2004. http://web4.library.adelaide.edu.au/theses/09PH/09phs7141.pdf.
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馮景良 and King-leung Fung. "Purification of Brassica juncea chitinase BJCHI1 from transgenic tobacco." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B31224374.
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Galagedara, Nelomie Nayanathara. "Identification of Quantitative Trait Loci for Resistance to Tan Spot in Durum Wheat." Thesis, North Dakota State University, 2018. https://hdl.handle.net/10365/28765.
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Tan spot, caused by Pyrenophora tritici-repentis (Ptr), is a major foliar disease on wheat. The pathosystem involves three pairs of necrotrophic effector (NE) and host sensitivity (S) gene interactions, namely Ptr ToxA-Tsn1, Ptr ToxB-Tsc2 and Ptr ToxC-Tsc1. Additionally, genetic factors conferring race-nonspecific resistance have been identified. The objectives of this study were to map tan spot resistance QTL and investigate the role of NE-S interactions in disease in durum using association and bi-parental mapping. Evaluation of a worldwide collection of durum accessions allowed identifying highly resistant nineteen lines to multiple Ptr races. Association mapping revealed genomic regions on chromosomes 1A, 2B and 3B significantly associated with resistance to tan spot, which likely correspond to Tsc1, Tsc2 and racenonspecific resistance. Using a bi-parental population derived from Ben and PI 41025, we found that ToxA-Tsn1 interaction plays no significant role in disease, instead a major race-nonspecific QTL on chromosome 5A was identified.
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Freeborough, Michael-John 1971. "A pathogen-derived resistance strategy for the broad-spectrum control of grapevine leafroll-associated virus infection." Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/53285.
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Thesis (PhD)--University of Stellenbosch, 2003.ENGLISH ABSTRACT: Grapevine leafroll-associated virus-3 is one of ten members of the C/osteroviridae that are known to infect grapevine. Nine of these viruses are associated with grapevine leafroll disease, of which GLRaV-1 and GLRaV-3 are the most important and widespread. Members of the C/osteroviridae are unique amongst the viruses, as it is the only known family whose members encode a heat shock protein 70 kOa homolog (Hsp70h). The Hsp70h is a movement protein (MP) that is required for the active translocation of the virion structure through the plasmodesmata into adjacent cells. Broad-spectrum resistance to unrelated viruses can be obtained by a pathogen-derived resistance (POR) strategy that is based on the expression of a dysfunctional MP in plants. The Hsp70h has two distinct domains. The N-terminal two thirds of the protein is an ATPase domain and shares high homology with the ATPase domains of all Hsp70h proteins from the C/osteroviridae and Hsp70 proteins from the prokaryote and eukaryote kingdoms. Conserved amino acids are found in the ATPase domain and are required for the positioning of the ATP at the catalytic site for ATP hydrolysis. The C-terminal domain is variable and the function of this domain in the Closteroviridae is not known. In prokaryote and eukaryote Hsp70 proteins, the C-terminal domain is required for protein-protein interactions. The American NY-1 isolate of GLRaV-3 has been sequenced and POR strategies have been attempted with the coat protein, divergent coat protein and replicase genes, but not with a dysfunctional form of the hsp70h gene. In this study, double-stranded RNA was isolated from a commercial vineyard with unknown virus status, but with distinct grapevine leafroll symptoms, and from two grapevine sources of known virus status, one with mild and one with severe symptoms. The GLRaV-3 hsp70h gene was amplified by RT-PCR from the dsRNA and the gene sequence was analysed. The hsp70h gene from the three virus sources contained more than 94% nucleotide sequence homology to the NY-1 isolate and the conserved amino acids required for ATPase activity were present. The hsp70h gene isolated from GLRaV-3 from a commercial Stellenbosch vineyard showing clear leafroll symptoms was selected for further work and was subjected to site-directed mutagenesis to engineer four point mutations in the gene. These four mutations resulted in the substitution of Asn for Asp", Gly for Thr1O, Lys for Glu 174 and Asn for Asp 197. The wild type (WT) and mutated (Mut) forms of the hsp 70h genes were cloned into a bacterial expression vector. Expression of both the WT- and Mut-Hsp proteins was achieved, and the protein was expressed in the insoluble inclusion bodies. All attempts to refold and isolate active proteins from the inclusion bodies were unsuccessful. Attempts to increase the concentration of soluble protein within the expressing bacteria were unsuccessful. Due to the lack of active protein, biochemical tests on the ATPase activity of the WT- and Mut-Hsp proteins could not be conducted. The wt- and mut-hsp genes were cloned into a plant expression vector for transformation into tobacco plants. These transformations were successful and gave rise to 22 Km' and 18 Km' plants from the WT- and Mut-Hsp constructs respectively. Two plant lines, M5 and M10, transformed with the mut-hsp transgene construct, appeared to have a high level of resistance to the challenging potato X potexvirus, whereas all the other tested plants were susceptible to the challenging virus. It was thus shown that a dysfunctional form of the GLRaV-3 Hsp70h could provide resistance to an unrelated virus in tobacco.
AFRIKAANSE OPSOMMING: Wingerdrolblaar-geassosieerde virus 3 (GLRaV-3) is een van 10 lede van die Closteroviridae wat wingerd kan infekteer. Nege van die virusse is met wingerdrolblaar geassosieer. Die GLRaV-1 en GLRaV-3 is die belangrikste en mees wyd verspreide lede van die rolblaar-geassosieerde Closteroviridae. Lede van die Closteroviridae is uniek in die opsig dat die virusse vir 'n 70 kDa-homoloë hitteresponsproteïen (Hsp70h) kodeer. Die Hsp70 is 'n bewegingsproteïen (MP) wat belangrik is vir die translokasie van die virus deur die plasmodesmata na die naasliggende sel. Breë-spektrum weerstand teen onverwante virusse kan behaal word deur 'n patogeen-afgeleide weerstandstrategie (POR), wat op die uitdrukking van 'n disfunksionele MP wat in plante uitgedruk word, gebaseer is. Die Hsp70hproteïen het twee gebiede. Die N-terminale gebied is In ATPase-gebied en toon hoë homologie met ander ATPase-gebiede van Hsp70h-proteïene van die Closteroviridae, asook die prokariotiese en eukariotiese koninkryke. Gekonserveerde aminosure wat belangrik is vir die posisionering van ATP in die katalitiese domein vir ATP-hidrolise is in die ATPase-gebied gevind. Die C-terminale gebied is variërend en die funksie van die gebied in die Closteroviridae is onbekend. In prokariotiese en eukariotiese Hsp70h-proteïene is die C-terminale gebied belangrik vir proteïenproteïen interaksies. Die nukleotiedvolgorde van die Amerikaanse NY-1-isolaat van GLRaV-3 is al bepaal en POR-strategieë is ook op die kapsiedproteïen, uiteenlopende kapsiedproteïen en die replikasie-proteïen uitgevoer, maar nog nie op 'n disfunksionele vorm van die Hsp70h-geen nie. In hierdie studie is dubbelstring-RNA (dsRNA) van 'n kommersiële wingerd met onbekende virusstatus wat rolblaarsimptome toon, geïsoleer, asook van twee wingerde met 'n bekende virusstatus, een met ligte en een met strawwe simptome. Die GLRaV-3 hsp70h-geen is met hulp van die polimerasekettingreaksie-metode (PKR) vanaf die dsRNA geamplifiseer en die geen se nukleotiedvolgorde is bepaal. Die hsp 70-gene van drie verskillende wingerde het meer as 94% homologie met die NY-1-isolaat getoon. Die gekonserveerde aminosure wat vir ATPase-aktiwiteit belangrik is, was teenwoordig. Die hsp70h-geen van GLRaV-3, wat uit 'n kommersiële wingerd met duidelike rolblaarsimptome in die Stellenbosch-gebied geïsoleer is, is vir verdere navorsing gekies en dit is aan setel-gerigte mutagenese blootgestelom vier mutasies van die geen te bewerkstellig. Die gevolg van hierdie vier mutasies was die verandering van Asn na Asp", Gly na Thr1o, Lys na Glu174 en Asn na Asp197. Die wilde (WT) en veranderde (Mut) vorms van die hsp-gene is in 'n bakteriese uitdrukkingsvektor gekloneer. Uitdrukking van beide die WT- en die Mut-Hspproteïene is behaal, maar die proteïene was in die onoplosbare fraksie geleë. Pogings om die onoplosbare proteïene te isoleer en in 'n aktiewe oplosbare vorm te verkry, was onsuksesvol. Verdere pogings om die proteïene in die oplosbare fraksie van die bakteriese ekspressiesisteem uit te druk, was ook onsuksesvol. As gevolg van die gebrek aan aktiewe proteïen kon biochemiese toetse nie op die ATPaseaktiwiteit van die WT- en Mut-Hsp proteïne gedoen word nie. Die wt- en mut-hsp-gene is ook in In plantekspressievektor gekloneer vir transformasie in tabakplante. Hierdie transformasies was suksesvol en het aanleiding gegee tot 22 kanamisienbestande (Km') en 18 Km' plante vanaf die WT- en Mut-Hspkonstrukte onderskeidelik. Twee plantlyne, M5 en M10, wat met die mut-hsptransgene getransformeer is, het 'n hoë vlak van weerstand teen die infekterende aartappelvirus X getoon in vergelyking met ander plante wat met die virus geïnfekteer is. Daar is dus bewys gelewer dat 'n disfunksionele vorm van die GLRaV-3 Hsp70h weerstand kan bied teen 'n onverwante virus in tabak.
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Rodríguez, Baixauli Ana María. "Genetic engineering of plant volatiles in fleshy fruits: pest repellency and disease resistance through D-limonene downregulation in transgenic orange plants." Doctoral thesis, Universitat Politècnica de València, 2013. http://hdl.handle.net/10251/31655.
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Los terpenos constituyen el mayor grupo de metabolitos secundarios, siendo
componentes de las glándulas de aceites esenciales, de las flores y de las resinas defensivas
de plantas aromáticas, a los que proporcionan sus aromas y sabores característicos. Los
terpenos volátiles se asocian a la defensa de muchas especies de plantas, animales y
microorganismos contra depredadores, patógenos y competidores. Por otra parte, estos
compuestos parecen servir como señales para atraer a los polinizadores y agentes dispersores
de semillas, así como a depredadores de plagas. El estudio de compuestos orgánicos volátiles
emitidos durante el desarrollo del fruto y después del desafío con diferentes agentes bióticos
puede ayudar a conocer las interacciones de los frutos carnosos no sólo con vertebrados
dispersores y depredadores, sino también con insectos y microorganismos.
Los frutos carnosos son particularmente ricos en volátiles. En los frutos cítricos, los
monoterpenos son los principales componentes de las glándulas del aceite esencial de la
cáscara (flavedo), siendo el D-limoneno el más abundante (hasta 95% en la naranja). Esta
característica hace que los cítricos sean un buen sistema modelo para el estudio de la función
de los terpenos en los frutos. La biología molecular moderna permite la realización de
experimentos para comprobar la función de terpenos por medio del uso de organismos
transformados genéticamente en los que se han manipulado los niveles de acumulación de
dichos compuestos. En este trabajo, se ha utilizado un plásmido que alberga el cDNA completo
del gen de una limoneno sintasa de cítricos (CiTMTSE1) en orientación antisentido (AS) o
sentido (S) para modificar la expresión y la acumulación de D-limoneno en plantas de naranjo
dulce (Citrus sinensis L. Osb.). La acumulación de D-limoneno en las frutas AS se redujo
drásticamente pero la acumulación de otros terpenos también se modificó, afectando a
compuestos tales como alcoholes monoterpenos, cuya concentración se incrementó en la
cáscara de las frutas. Las plantas transformadas fueron morfológicamente indistinguibles de las
plantas control (WT) y de las plantas transformadas con el vector vacío (EV).
Los frutos transgénicos fueron desafiados con un insecto plaga y con diferentes
patógenos para probar si la alteración de los niveles de acumulación de estos volátiles daba
como resultado una mejora en la respuesta del flavedo frente a plagas y patógenos. Los
machos de la mosca mediterránea de la fruta (Ceratitis capitata) expuestos a las frutas AS y EV
en ensayos en túnel de viento fueron significativamente más atraídos por el aroma de los frutos
control EV. En otros experimentos de desafío con el hongo de la podredumbre verde
Penicillium digitatum y la bacteria causante de la cancrosis de los cítricos Xanthomonas
axonopodis subsp. citri, las frutas transgénicas con un contenido reducido de D-limoneno
mostraron elevada resistencia a estos patógenos. El alto contenido en D-limoneno en la
cáscara de naranjas maduras puede ser una señal para la atracción de plagas y
microorganismos que podrían estar involucrados en la facilitación del acceso a la pulpa de los
frugívoros dispersores de semillas.
El análisis de la expresión génica global en el flavedo de las frutas transgénicas vinculó
la disminución de D-limoneno y la reducción de la expresión de genes del metabolismo de
monoterpenos con la activación de la expresión de genes implicados en inmunidad innata,
incluyendo factores de transcripción, genes de quinasas implicadas en la entrada de Ca2+ en la
célula y genes implicados en la activación de las cascadas de MAPKs, con la consiguiente
activación de la ruta de señalización de ácido jasmónico (JA), lo que provocó la activación del
metabolismo de JA y un aumentó drástico de la acumulación de JA en la cáscara de la naranja
tras el desafío con P. digitatum, lo que explicaría la resistencia al menos a hongos necrotrofos
observada en las frutas.
Estos resultados indican que la acumulación de D-limoneno en la cáscara de la naranja
estaría implicada en la interacción trófica entre las frutas, insectos y microorganismos, lo cual
proporciona una visión mucho más amplia de las funciones de los terpenos en la naturaleza.
También representa una alternativa muy prometedora para incrementar la resistencia o
tolerancia de las plantas frente a patógenos y plagas.Terpenes, the largest group of secondary metabolites, are well known as constituents of essential oils, floral scents and defensive resins of aromatic plants, to which they impart their characteristic aromas and flavors. Terpene volatiles defend many species of plants, animals and microorganisms against predators, pathogens and competitors. Moreover, those compounds seem to serve as advertisements to attract pollinators and seed-dispersal agents as well as pest predators. The study of VOCs emitted during fruit development and after challenge with different biotic agents may help to determine the interactions of fleshy fruits not only with legitimate vertebrate dispersers and predators, but also with insects and microorganisms. Fleshy fruits are particularly rich in volatiles. In citrus fruits, monoterpenes are the main components of the essential oil glands of the peel, being D-limonene the most abundant one (up to 95% in orange fruits). This characteristic makes citrus a good model system for studying the function of terpenes in plants. Modern molecular biology now enable experiments to test terpenoid function by the use of genetically transformed organisms in which terpene levels have been manipulated. In this work, a plasmid harboring the complete cDNA of a citrus limonene synthase gene (CiTMTSE1) in antisense (AS) or sense (S) orientation was used to modify the expression and accumulation of D-limonene of sweet orange (Citrus sinensis L. Osb) plants. D-limonene accumulation in AS fruits was dramatically reduced but the accumulation of other terpenoids was also modified, such as monoterpene alcohols, whose concentration increased in the peel of fruits. Genetically transformed plants were morphologically indistinguishable from wild-type (WT) and empty vector (EV) control plants. Transgenic fruits were challenged against a pest and different pathogens to test whether volatile profile alteration results in an improvement in the response of the fruit flavedo against them. Males of the Mediterranean fruit fly (Ceratitis capitata) exposed to AS fruits versus EV in wind tunnel assays were significantly more attracted to the odor of EV control fruits. In separate experiments with the green mould rot of citrus fruits and citrus canker caused by Penicillium digitatum and Xanthomonas axonopodis subsp. citri, respectively, transgenic fruits with a reduced content in D-limonene showed resistance to both pathogens. High D-limonene content in mature orange peels may be a signal for attractiveness of pests and microorganisms which might be likely involved in facilitating the access to the pulp of seed dispersal frugivores. A global gene expression analysis of the flavedo of AS transgenic fruits linked the decrease of D-limonene and monoterpene metabolism to the up-regulation of genes involved in the innate immunity response, including transcription factors together with Ca2+ entry into the cell and activation of MAPK cascades, contributing to activation of jasmonic acid (JA) signaling, which triggered the up-regulation of JA metabolism and drastically increased the accumulation of JA in orange peels upon fungal challenge, explaining the resistance to necrotrophic fungi observed in AS fruits. These results indicate that limonene accumulation in the peel of citrus fruit appears to be involved in the successful trophic interaction between fruits, insects, and microorganisms and provide a much more comprehensive view of roles of terpenes in nature. It also represents a very promising alternative for increasing resistance or tolerance of plants to pathogens.
Rodríguez Baixauli, AM. (2013). Genetic engineering of plant volatiles in fleshy fruits: pest repellency and disease resistance through D-limonene downregulation in transgenic orange plants [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/31655
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Njom, Henry Akum. "Mechanism and synchronicity of wheat (Triticum aestivum) resistance to leaf rust (Puccinia triticina) and Russian wheat aphid (Duiraphis noxia) SA1." Thesis, University of Fort Hare, 2016. http://hdl.handle.net/10353/2700.
Full textAbstract:
Wheat (Triticum aestivum and T. Durum) is an extremely important agronomic crop produced worldwide. Wheat consumption has doubled in the last 30 years with approximately 600 million tons consumed per annum. According to the International Maize and Wheat Improvement Center, worldwide wheat demand will increase over 40 percent by 2020, while land as well as resources available for the production will decrease significantly if the current trend prevails. The wheat industry is challenged with abiotic and biotic stressors that lead to reduction in crop yields. Increase knowledge of wheat’s biochemical constitution and functional biology is of paramount importance to improve wheat so as to meet with this demand. Pesticides and fungicides are being used to control biotic stress imposed by insect pest and fungi pathogens but these chemicals pose a risk to the environment and human health. To this effect, there is re-evaluation of pesticides currently in use by the Environmental Protection Agency, via mandates of the 1996 Food Quality Protection Act and those with higher perceived risks are banned. Genetic resistance is now a more environmental friendly and effective method of controlling insect pest and rust diseases of wheat than the costly spraying with pesticides and fungicides. Although, resistant cultivars effectively prevent current prevailing pathotypes of leaf rust and biotypes of Russian wheat aphid from attacking wheat, new pathotypes and biotypes of the pathogen/pest may develop and infect resistant cultivars. Therefore, breeders are continually searching for new sources of resistance. Proteomic approaches can be utilised to ascertain target enzymes and proteins from resistant lines that could be utilised to augment the natural tolerance of agronomically favourable varieties of wheat. With this ultimate goal in mind, the aim of this study was to elucidate the mechanism and synchronicity of wheat resistance to leaf rust (Puccinia triticina) and Russian wheat aphid (Duiraphis noxia) SA1. To determine the resistance mechanism of the wheat cultivars to leaf rust infection and Russian wheat aphid infestation, a proteomics approach using two-dimensional gel electrophoresis was used in order to determine the effect of RWA SA1 on the wheat cultivars proteome. Differentially expressed proteins that were up or down regulated (appearing or disappearing) were identified using PDQuestTM Basic 2-DE Gel analysis software. Proteins bands of interest were in-gel trypsin digested as per the protocol described in Schevchenko et al. (2007) and analysed using a Dionex Ultimate 3000 RSLC system coupled to an AB Sciex 6600 TripleTOF mass spectrometer. Protein pilot v5 using Paragon search engine (AB Sciex) was used for comparison of the obtained MS/MS spectra with a custom database containing sequences of Puccinia triticina (Uniprot Swissprot), Triticum aestivum (Uniprot TrEMBL) and Russian wheat aphid (Uniprot TrEMBL) as well as a list of sequences from common contaminating proteins. Proteins with a threshold of ≥99.9 percent confidence were reported. A total of 72 proteins were putatively identified from the 37 protein spots excised originating from either leaf rust or Russian wheat aphid experiments. Sixty-three of these proteins were associated with wheat response to stress imposed by RWA SA1 feeding while 39 were associated with infection by Puccinia triticina. Several enzymes involved in the Calvin cycle, electron transport and ATP synthesis were observed to be differentially regulated suggesting greater metabolic requirements in the wheat plants following aphid infestation and leaf rust infection. Proteins directly associated with photosynthesis were also differentially regulated following RWA SA1 infestation and P.
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Maios, Claudia. "Expression of defence-related genes in sugar beet plants infected with Rhizoctonia solani and treated with benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH)." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99349.
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The chemicals inducers SA, BABA, and BTH were tested as seed treatment and soil drench on a partial-resistant cultivar of sugar beet grown in sand infested with the Rhizoctonia solani AG 2-2IIIB. In another series of experiments, BTH was applied as soil drench on sugar beet plants inoculated with R. solani. The chemical inducers were ineffective in reducing pre-emergence damping-off and post-emergence plant mortality. Despite these results, treatment with BTH altered the levels of expression ratios of four defence encoding genes associated with systemic resistance: chitinase, peroxidase, chalcone isomerase, and chalcone synthase. BTH sensitised sugar beet plants without the necessity of R. solani infection to up-regulate substantially the transcript level ratios of chalcS and chit3, while levels of chalcI were down-regulated levels below 1. Of interest, was the significant increase of transcript levels of chit3 in sugar beet plants infected with R. solani and treated with BTH. In conclusion, sugar beet plants were capable of over expressing selected genes in response to a chemical inducer, but contrary to what had been reported, gene activation in sugar beet as a result of BTH treatment does not confer disease resistance against R. solani.
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Williams, Kevin John. "Biological and genetic studies of wheat resistance to Heterodera avenae." Title page, summary and contents only, 1994. http://web4.library.adelaide.edu.au/theses/09PH/09phw7238.pdf.
Full textBooks on the topic "Plants Disease and pest resistance"
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Sharma, Indu. Disease resistance in wheat. Wallingford, Oxfordshire, UK: CABI, 2012.
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1960-, Parker Jane, ed. Molecular aspects of plant disease resistance. Ames, Iowa: Blackwell, 2008.
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S, Fraser R. S., ed. Mechanisms of resistance to plant diseases. Dordrecht, Netherlands: M. Nijhoff/W. Junk, 1985.
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S, Sadasivam. Molecular host plant resistance to pests. New York: Marcel Dekker, 2003.
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David, Evered, and Harnett Sara, eds. Plant resistance to viruses. Chichester: Wiley, 1987.
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National Research Council (U.S.). Committee on Genetically Modified Pest-Protected Plants., ed. Genetically modified pest-protected plants: Science and regulation. Washington, D.C: National Academy Press, 2000.
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J, Slusarenko A., Fraser R. S. S, and Loon L. C. van, eds. Mechanisms of resistance to plant diseases. Dordrecht: Kluwer Academic Publishers, 2000.
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Deverall, Brian J. Defence mechanisms of plants. Cambridge: Cambridge University Press, 2009.
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Rosenthal, Ed. Marijuana pest and disease control. Oakland, CA: Quick American, 2012.
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W, Onstad David, ed. Insect resistance management: Biology, economics, and prediction. Amsterdam: Elsevier, 2008.
Find full textBook chapters on the topic "Plants Disease and pest resistance"
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Wain, R. L. "Some Chemical Aspects of Plant Disease Resistance." In Natural Resistance of Plants to Pests, 16–21. Washington, DC: American Chemical Society, 1986. http://dx.doi.org/10.1021/bk-1986-0296.ch002.
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Voisey, C. R., B. Dudas, R. Biggs, E. P. J. Burgess, P. J. Wigley, P. G. McGregor, T. J. Lough, D. L. Beck, R. L. S. Forster, and D. W. R. White. "Transgenic Pest and Disease Resistant White Clover Plants." In Developments in Plant Breeding, 239–50. Dordrecht: Springer Netherlands, 2001. http://dx.doi.org/10.1007/978-94-015-9700-5_14.
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Bruenn, Jeremy. "Novel Methods of Introducing Pest and Disease Resistance to Crop Plants." In Genetic Engineering, 11–22. Boston, MA: Springer US, 2000. http://dx.doi.org/10.1007/978-1-4615-4199-8_2.
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Cuartero, Jesús, Henri Laterrot, and Joop C. van Lenteren. "Host- Plant Resistance to Pathogens and Arthropod Pests." In Integrated Pest and Disease Management in Greenhouse Crops, 124–38. Dordrecht: Springer Netherlands, 1999. http://dx.doi.org/10.1007/0-306-47585-5_9.
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Ramjegathesh, R., R. Samiyappan, T. Raguchander, K. Prabakar, and D. Saravanakumar. "Plant–PGPR Interactions for Pest and Disease Resistance in Sustainable Agriculture." In Bacteria in Agrobiology: Disease Management, 293–320. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-33639-3_11.
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Singh, Dhan Pal. "Production of Disease-Resistant Plants by Unconventional Breeding." In Breeding for Resistance to Diseases and Insect Pests, 154–61. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-71512-9_7.
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Robdrup, Melissa, Michelle Hubbard, Linda Yuya Gorim, and Monika A. Gorzelak. "Arbuscular Mycorrhizal Fungi Under Intercrop, Regenerative, and Conventional Agriculture Systems." In Arbuscular Mycorrhizal Fungi and Higher Plants, 287–318. Singapore: Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-99-8220-2_13.
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AbstractArbuscular mycorrhizal fungi (AMF) increase in diversity and abundance in agricultural systems that emphasize soil health practices, including regenerative agriculture and intercropping. Regenerative agriculture in principle includes any practice that increases biodiversity and living roots and integrates livestock while reducing tillage, bare soil, and agrichemical inputs. Intercropping increases biodiversity in an annual system and reduces disease prevalence and weeds while improving soil conditions and yielding more than the equivalent monocrop. These principles and practices simultaneously support AMF proliferation in soils and in turn AMF provide multiple benefits to crops. AMF colonize roots, trading photosynthates for nutrients acquired beyond the reach of the plant root system. While colonizing roots, they trigger innate plant immunity and confer resistance to some insect, fungal, and bacterial pests. Colonized plants hold more water and thus are more resistant to drought. In soils with ample AMF propagules, multiple plants are likely to become connected to their neighbors by a common mycorrhizal network (CMN). Plants connected by a CMN are likely to share beneficial microbes, resistance to disease, and resources. A better understanding of crop root traits and AMF is important to building a wholistic picture of ecological interactions that can be leveraged to maintain agricultural production in intercropped, regenerative, and conventional systems.
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Lefebvre, Véronique, Nathalie Boissot, and Jean-Luc Gallois. "Host Plant Resistance to Pests and Pathogens, the Genetic Leverage in Integrated Pest and Disease Management." In Integrated Pest and Disease Management in Greenhouse Crops, 259–83. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-22304-5_9.
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Barquero-Miranda, Miguel, María José Cordero-Vega, and Kimberly Ureña-Ureña. "Inoculation and Evaluation of Hemileia vastatrix Under Laboratory Conditions." In Mutation Breeding in Coffee with Special Reference to Leaf Rust, 225–32. Berlin, Heidelberg: Springer Berlin Heidelberg, 2023. http://dx.doi.org/10.1007/978-3-662-67273-0_16.
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AbstractThe coffee leaf rust, a disease caused by the biotrophic fungus Hemileia vastatrix, is one of the main limitations in coffee production today as it causes significant economic losses to the coffee production sector. Genetic improvement is an option to solve these problems. The Arabica varieties have a very narrow genetic base therefore the induction of mutations, through e.g. physical methods such as gamma rays, could be an efficient tool to increase the genetic diversity of the crop. This would allow to obtain desirable agronomic characteristics such as resistance to pests and diseases. To determine the effect of irradiation on the plants, protocols enabling evaluation of improved traits must be applied. In the case of the assessment of plant resistance to pests and diseases, screening protocols that take into account their biology should be considered. This chapter provides a detailed protocol for the inoculation and evaluation of Hemileia vastatrix under laboratory conditions.
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Mithen, Richard. "Leaf glucosinolate profiles and their relationship to pest and disease resistance in oilseed rape." In Developments in Plant Pathology, 71–83. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-017-0954-5_6.
Full textConference papers on the topic "Plants Disease and pest resistance"
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Sandeepanie, W. D. Nilakshi, Samadhi Rathnayake, and Amali Gunasinghe. "Disease Identification and Mapping using CNN in Paddy Fields." In SLIIT International Conference on Advancements in Sciences and Humanities 2023. Faculty of Humanities and Sciences, SLIIT, 2023. http://dx.doi.org/10.54389/nkkj6476.
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Rice, a globally vital staple crop, sustains over half of the world’s caloric needs while supporting the livelihoods of small-scale farmers and landless laborers. The escalating global population has led to an increased demand for rice production. Sri Lanka, renowned for its premium rice quality, has a rich history of paddy cultivation. However, a substantial portion of the country’s 708,000 hectares of paddy land remains underutilized due to water scarcity and unstable terrain. The objective of this project is to enhance paddy crop quality during the critical vegetative phase by employing machine learning and web development for early disease identification. The vegetative phase significantly influences overall yield, resistance to pests and diseases, nutrient assimilation, and environmental sustainability in agriculture. This project primarily focuses on early disease identification during this phase and presents the findings through a user-friendly map interface. Early identification of paddy diseases is vital for effective crop management and high yields. These diseases, caused by various pathogens, can severely impede plant growth and productivity if not promptly detected and treated. Identifying them early enables farmers and experts to take timely, targeted actions such as applying suitable fungicides or implementing cultural practices to control their spread and minimize crop damage. A logical map, displaying disease spread percentages, will gauge the impact of infections on paddy plants. The reliability of this mapping process hinges on model accuracy, which was rigorously validated using multiple metrics to ensure its effectiveness.
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Barcenilla, Jomer Allan G., and Christian V. Maderazo. "Identifying Common Pest and Disease of Lettuce Plants Using Convolutional Neural Network." In 2023 2nd International Conference on Futuristic Technologies (INCOFT). IEEE, 2023. http://dx.doi.org/10.1109/incoft60753.2023.10424991.
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Козарь, Елена, И. Енгалычева, А. Антошкин, Е. Козарь, Наталия Мащенко, and Ала Боровская. "Использование вторичных метаболитов высших растений для обработки семян фасоли." In VIIth International Scientific Conference “Genetics, Physiology and Plant Breeding”. Institute of Genetics, Physiology and Plant Protection, Republic of Moldova, 2021. http://dx.doi.org/10.53040/gppb7.2021.15.
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The use of preparations based on secondary plant metabolites is an alternative to chemical pesti-cides, to which the vegetable bean culture is very sensitive. Аll preparations stimulate the germination and development of the root system of seedlings, which contributes to an increase in the germination and resistance of beans to Fusarium in the early stages of development. 0.01% concentration is the most op-timal for treating beans before sowing. Verbascoside exhibits a prolonged immunomodulatory effect and effectively inhibits the development of the disease throughout the growing season. Bioregulators mold-stim and linaroside work more effectively together with chemical fungicides, reducing their phytotoxicity and increasing plant stress resiastance.
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Paladi, Ion, Leonid Volosciuc, and Dana Paladi. "Protecția integrată a florii-soarelui în agricultura convențională și ecologică." In Scientific International Symposium "Plant Protection – Achievements and Perspectives". Institute of Genetics, Physiology and Plant Protection, Republic of Moldova, 2023. http://dx.doi.org/10.53040/ppap2023.10.
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Sunflower is the plant of major importance for agriculture in the Republic of Moldova, unpretentious to soil and technology and resistant to drought. Having a high share in rotation, it becomes more and more exposed to diseases and pests, determining the need for an integrated protection system. But the market is showing an increase in demand for organic products, and society is demanding that chemical pressure on agriculture be reduced. This will compare the conventional and ecological protection system.
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Doltu, Mădălina, Dorin Sora, and Vlad Bunea. "RESULTS OF SOME ROMANIAN TOMATO AND EGGPLANT CULTIVARS GRAFTED ONTO INTERSPECIFIC (GENUS LYCOPERSICON) ROOTSTOCK." In GEOLINKS Conference Proceedings. Saima Consult Ltd, 2021. http://dx.doi.org/10.32008/geolinks2021/b1/v3/21.
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This experience aims at identifying an optimal rootstock for Romanian tomato and eggplant cultivars and the influence on plant yield and growth. These vegetables (tomato and eggplant) are very important crops worldwide and in Romania. Tomato and eggplant plants are very sensitive to climatic fluctuations and can affect fruit yield. Grafting on species from the Solanaceae family is a practice that increases productivity, fruit quality, resistance to diseases and pests, abiotic factors. The work was conducted at the Horting Research Institute, Romania. The biological material used was different tomato and eggplant; two scions, Siriana F1 (tomato), Luiza variety (eggplant) and a rootstock, Emperador F1 (tomato). The Emperador rootstock and others are very used in worldwide for ecological and conventional cultures. By comparing the tomato and the eggplant yield of the researched grafted and non-grafted variants it has been shown that grafted cultivars have had very good values, being higher with 19.78% and 29.13% than at non-grafted plants. Following the studies undertaken in the research greenhouse period 2019-2020, a rootstock from genus Lycopersicum (Emperador) was tested and some results are in this scientific paper.
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Corneanu, Mihaela, Cornelia Buzatu-Goanta, and Constantin Netoiu. "Quantitative characters variability and diseases / pests’ tolerance of some of Salix SP. Accessions." In VIIth International Scientific Conference “Genetics, Physiology and Plant Breeding”. Institute of Genetics, Physiology and Plant Protection, Republic of Moldova, 2021. http://dx.doi.org/10.53040/gppb7.2021.99.
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The oil crisis of the last decades of the twentieth century has led researchers to turn their attention to alternative sources of energy, the so-called green energy. One of the genres intensively studied for bi-omass production was the genus Salix. In Europe, in Sweden, were made the first Salix hybrids for short-rotation crops (SRC). Willows are used for wood plantation, cellulose and paper production, in pharma-ceutical industry, for soil phytoremediation, like pioneer species by their role in ecosystem restoration, increasing biodiversity and for biomass production (Berg, 2002). In Romania, willow SRC for biomass production started after 2005. There are about 1500 ha of willow SRC, 400 ha of them are in Banat area. All of these cultures were established with Swedish clones, especially clone Inger. Swedish clones and hybrids registered good results in Sweden and North-West Europe countries with cool, wet climate, but in Romania they have not achieved spectacular results in some areas, such as North-Est Timis county and Oltenia area, the crops being compromised in the first years. In the view of the extension of cultivated areas unsuitable for agriculture, with forestry and energy crops, there are necessary comprehensive studies to find optimal solutions - selection of genotypes to their potential production, but also to be adapted at temperatures over 35ºC and severe drought. A willow breeding program for the biomass production has to be started and a potential genitors collection (local germplasm) sets the stage for the beginning of a science-based breeding program. The collection of potential genitors (39 genotypes, 12 species) was established in the spring of 2015 on the territory of the Experimental Didactical Station belonging to Banat’s University of Agricul-tural Sciences and Veterinary Medicine from Timisoara. The biological material (46 cuttings for each genotype) was planted in double rows 75 cm apart with double rows spaced at 150 cm and an 80 cm in-row spacing. During the growing season was made chemical and mechanical weed control. There were not applied phytosanitary treatments, in order to test the natural resistance of the genotypes. The sprouting capacity and biometric observations were made in an experimental trial with uncut and cutback shoots and biomass was estimated. Following the biometric observations performed biannually and the evaluation of tolerance / re-sistance to diseases and pests, a wide variability was noticed, both interspecific and intraspecific. The quantitative traits varied significantly with genotype and management practice. Large variability was ob-served in terms of survival rate but also in sprouting capacity, maximum height, and diameter. The field trial recommends some genotypes with particularly high production, clone 30 Salix pentandra L. and clone 31 S. triandra L. for crops with short rotation cycle, both in normal soil and climatic conditions and on degraded lands. The most tolerant genotypes both to pests and diseases were belonging to S. rosmarinifolia and S. pentandra. The most sensitive species include genitors from S. fragilis, S.alba and S.purpurea. Tolerance to pests and diseases was dependent on species and origin.
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Zinovieva, S. V., Z. V. Udalova, and F. K. Khasanov. "EXPRESSION OF IMMUNE SYSTEM GENES IN TOMATO PLANTS INFECTED BY MELOIDOGYNE INCOGNITA." In THEORY AND PRACTICE OF PARASITIC DISEASE CONTROL. VNIIP – FSC VIEV, 2024. http://dx.doi.org/10.31016/978-5-6050437-8-2.2024.25.135-139.
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Data were presented from a study on expression of resistance gene Mi-1.2 of protective genes of the PR gene family (PR-2, PR-3) and genes of serine and cysteine proteinase (PIser PIcys) inhibitors in tissues of tomato plants of resistant and susceptible hybrids infected by gall nematodes and an assessment of their role in parasite resistance was given. Differences were detected in the expression of the studied genes at all stages of nematode development in the roots of resistant and susceptible plants. The studies showed that the infection of resistant plants caused an increase in the study gene transcripts as early as in the initial period of infection, which indicated the response time to nematode larvae penetration and the speed of adequate protective response. Changes in the defense response-related gene expression in infected susceptible plants were insignificant and appeared after the larvae penetrated the roots, which may be one of the reasons for disease progress. The increased expression of the studied genes that encode protective proteins in infected roots of resistant plants found at all parasite development stages indicates the importance of protective proteins in tomato plant resistance to gall nematode.
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TOADER, Elena Violeta, George TOADER, Daniela TRIFAN, Emanuela LUNGU, and Alin-Ionel GHIORGHE. "INNOVATIVE ECOLOGICAL TECHNOLOGIES FOR SOIL RESTORATION: BACTERIAL BIOPREPARATIONS." In Competitiveness of Agro-Food and Environmental Economy. Editura ASE, 2022. http://dx.doi.org/10.24818/cafee/2021/10/09.
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The use of fertilizer products in agricultural crops is a beneficial source of supplementing the nutrients needed for the growth and development of both plants and an increase in agricultural production. However, often the fertilizer doses applied per hectare to agricultural crops are not respected. Failure to comply with the applied fertilizer doses will lead to the occurrence of negative phenomena for soil, environment and agricultural crops, implicitly for human and animal health. Increasing the fertilizer doses per hectare and not respecting them will lead to the occurrence of soil acidification. The decrease of the bacterial colonies in the soil will bring with it a decrease of the humification processes, of the decomposition and solubilization processes of the complex compounds in the soil as well as favoring the leaching and appearance of the complex compounds in the soil (in large quantities). The increase of complex compounds in the soil will lead to a decrease in pH (below pH 7), which will lead to an increase in soil acidity. On acidic soil, crops will not reach their maximum potential in productivity. The use of bacterial biopreparation technologies in agricultural crops plays an important role in plant protection. Some bacterial cultures give plants a protection against pedo-climatic stress, a resistance to the attack of diseases and pests as well as conferring a protection on environmental factors (drought, heavy rainfall, cold, etc.). The use of these bacterial products as fertilizers as well as plant protection products has been shown to have great potential in growing, developing, maximizing agricultural production, in restoring and greening the soil and its beneficial flora, the role of these biological fertilizers being to address a green, sustainable, sustainable agriculture and achieving high, healthy, nutrient-rich productivity, beneficial to human and animal health.
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Aukhadieva, E. A., R. A. Daukaev, G. R. Allayarova, and E. E. Zelenkovskaya. "Evaluation of the success of the introduction of species of the genus Iris L. in the conditions of the forest-steppe zone of the Bashkir Cis-Urals." In III All-Russian Scientific Conference with International Participation "Science, technology, society: Environmental engineering for sustainable development of territories". Krasnoyarsk Science and Technology City Hall, 2022. http://dx.doi.org/10.47813/nto.3.2022.6.674-678.
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Irises are ornamental and adaptable plants that are of interest to many scientists around the world. The present studies were carried out on the basis of the SUBSI RAS. The success of the introduction of 10 species of the genus Iris in the conditions of the forest-steppe zone of the Bashkir Cis-Urals was assessed, seed productivity, pollen viability and the ability to autogamy were identified. The evaluation results showed that all the studied species are promising and very promising. The very promising group includes I. pseudacorus and I. sibirica, which are representatives of the flora of the Republic of Bashkortostan, as well as I. lactea. Plants have a high vitality, resistant to diseases and pests. Other species are promising for introduction in introduced conditions. The species are highly adapted to the climate of the forest-steppe zone of the Bashkir Cis-Urals and can be successfully grown and widely used in landscaping settlements and in breeding work.
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Kostromycheva, E. V., and N. E. Pavlovskaya. "THE GORDDETINNYI BIOLOGICAL MEANS OF PROTECTION OF PLANTS FROM DISEASE WRITERS." In The All-Russian Scientific Conference with International Participation and Schools of Young Scientists "Mechanisms of resistance of plants and microorganisms to unfavorable environmental". SIPPB SB RAS, 2018. http://dx.doi.org/10.31255/978-5-94797-319-8-604-607.
Full textReports on the topic "Plants Disease and pest resistance"
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Michel Jr., Frederick C., Harry A. J. Hoitink, Yitzhak Hadar, and Dror Minz. Microbial Communities Active in Soil-Induced Systemic Plant Disease Resistance. United States Department of Agriculture, January 2005. http://dx.doi.org/10.32747/2005.7586476.bard.
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Induced Systemic Resistance (ISR) is a highly variable property that can be induced by compost amendment of potting media and soils. For example, previous studies showed that only 1 of 79 potting mixes prepared with different batches of mature composts produced from several different types of solid wastes were able to suppress the severity of bacterial leaf spot of radish caused by Xanthomonas campestris pv. armoraciae compared with disease on plants produced in a nonamended sphagnum peat mix. In this project, microbial consortia in the rhizosphere of plants grown in ISR-active compost-amended substrates were characterized. The plants used included primarily cucumber but also tomato and radish. Rhizosphere microbial consortia were characterized using multiple molecular tools including DGGE (Israel) and T -RFLP (Ohio) in both ISR-active field plots and potting media. Universal as well as population-specific bacterial and fungal PCR primers were utilized. T -RFLP analyses using universal bacterial primers showed few significant differences in overall bacterial community composition in ISR-active and inactive substrates (Ohio). In addition, the community members which were significantly different varied when different ISR-activecomposts were used (Ohio). To better characterize the shifts in microbial community structure during the development of ISR, population specific molecular tools were developed (Israel, Ohio).-PCR primers were designed to detect and quantify bacterial groups including Pyrenomycetes, Bacillus, Pan toea, Pseudomonas, Xanthomonas and Streptomyces as well as Trichoderma and Fusarium; two groups of fungi that harbor isolates which are ISR active (Isreal and Ohio). Bacterial consortia associated with cucumber plants grown in compost-amended potting mixtures were shown to be dominated by the phylogenetic taxon Bacteroidetes, including members of the genus Chryseobacterium, which in some cases have been shown to be involved in biocontrol (Israel). Nested-PCR-DGGE analyses coupled with long l6S rDNA sequencing, demonstrated that the Chryseobacteriumspp. detected on seed and the root in compost-amended treatments were derived from the compost itself. The most effective ISR inducing rhizobacterial strains were identified as Bacillus sp. based on partial sequencing of l6S rDNA. However, these strains were significantly less effective in reducing the severity of disease than Trichoderma hamatum382 (T382). A procedure was developed for inoculation of a compost-amended substrate with T -382 which consistently induced ISR in cucumber against Phytophthora blight caused by Phytophthora capsiciand in radish against bacterial spot (Ohio). Inoculation of compost-amended potting mixes with biocontrol agents such as T -382 and other microbes that induce systemic resistance in plants significantly increased the frequency of systemic disease control obtained with natural compost amendments.
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Chejanovsky, Nor, and Bruce A. Webb. Potentiation of Pest Control by Insect Immunosuppression. United States Department of Agriculture, January 2010. http://dx.doi.org/10.32747/2010.7592113.bard.
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The restricted host range of many baculoviruses, highly pathogenic to Lepidoptera and non-pathogenic to mammals, limits their use to single or few closely related Lepidopteran species and is an obstacle to extending their implementation for pest control. The insect immune response is a major determinant of the ability of an insect pathogen to efficiently multiply and propagate. We have developed an original model system to study the Lepidopteran antiviral immune response based on Spodoptera littoralis resistance to AcMNPV (Autographa californica multiple nucleopolyhedrovirus) infection and the fascinating immunosuppressive activity of polydnaviruses .Our aim is to elucidate the mechanisms through which the immunosuppressive insect polydnaviruses promote replication of pathogenic baculoviruses in lepidopteran hosts that are mildly or non-permissive to virus- replication. In this study we : 1- Assessed the extent to which and the mechanisms whereby the immunosuppressive Campoletis sonorensis polydnavirus (CsV) or its genes enhanced replication of a well-characterized pathogenic baculovirus AcMNPV, in polydnavirus-immunosuppressedH. zea and S. littoralis insects and S. littoralis cells, hosts that are mildly or non-permissive to AcMNPV. 2- Identified CsV genes involved in the above immunosuppression (e.g. inhibiting cellular encapsulation and disrupting humoral immunity). We showed that: 1. S. littoralis larvae mount an immune response against a baculovirus infection. 2. Immunosuppression of an insect pest improves the ability of a viral pathogen, the baculovirus AcMNPV, to infect the pest. 3. For the first time two PDV-specific genes of the vankyrin and cystein rich-motif families involved in immunosuppression of the host, namely Pvank1 and Hv1.1 respectively, enhanced the efficacy of an insect pathogen toward a semipermissive pest. 4. Pvank1 inhibits apoptosis of Spodopteran cells elucidating one functional aspect of PDVvankyrins. 5. That Pvank-1 and Hv1.1 do not show cooperative effect in S. littoralis when co-expressed during AcMNPV infection. Our results pave the way to developing novel means for pest control, including baculoviruses, that rely upon suppressing host immune systems by strategically weakening insect defenses to improve pathogen (i.e. biocontrol agent) infection and virulence. Also, we expect that the above result will help to develop systems for enhanced insect control that may ultimately help to reduce transmission of insect vectored diseases of humans, animals and plants as well as provide mechanisms for suppression of insect populations that damage crop plants by direct feeding.
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Steffens, John C., and Eithan Harel. Polyphenol Oxidases- Expression, Assembly and Function. United States Department of Agriculture, January 1995. http://dx.doi.org/10.32747/1995.7571358.bard.
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Polyphenol oxidases (PPOs) participate in the preparation of many plant products on the one hand and cause considerable losses during processing of plant products on the other hand. However, the physiological functions of plant PPO were still a subject of controversy at the onset of the project. Preliminary observations that suggested involvement of PPOs in resistance to herbivores and pathogens held great promise for application in agriculture but required elucidation of PPO's function if modulation of PPO expression is to be considered for improving plant protection or storage and processing of plant products. Suggestions on a possible role of PPO in various aspects of chloroplast metabolism were also relevant in this context. The characterization of plant PPO genes opened a way for achieving these goals. We reasoned that "understanding PPO targeting and routing, designing ways to manipulate its expression and assessing the effects of such modifications will enable determination of the true properties of the enzyme and open the way for controlling its activity". The objective of the project was to "obtain an insight into the function and biological significance of PPOs" by examining possible function(s) of PPO in photosynthesis and plant-pest interactions using transgenic tomato plants; extending our understanding of PPO routing and assembly and the mechanism of its thylakoid translocation; preparing recombinant PPOs for use in import studies, determination of the genuine properties of PPOs and understanding its assembly and determining the effect of PPO's absence on chloroplast performance. Results obtained during work on the project made it necessary to abandon some minor objectives and devote the effort to more promising topics. Such changes are mentioned in the 'Body of the report' which is arranged according to the objectives of the original proposal. The complex expression pattern of tomato PPO gene family was determined. Individual members of the family are differentially expressed in various parts of the plant and subjected to developmentally regulated turnover. Some members are differentially regulated also by pathogens, wounding and chemical wound signals. Wounding systemically induces PPO activity and level in potato. Only tissues that are developmentally competent to express PPO are capable of responding to the systemic wounding signal by increased accumulation of PPO mRNA. Down regulation of PPO genes causes hyper susceptibility to leaf pathogens in tomato while over expression regulation of PPO expression in tomato plants is their apparent increased tolerance to drought. Both the enhanced disease resistance conferred by PPO over expression and the increased stress tolerance due to down regulation can be used in the engineering of improved crop plants. Photosynthesis rate and variable fluorescence measurements in wild type, and PPO-null and over expressing transgenic tomato lines suggest that PPO does not enable plants to cope better with stressful high light intensities or reactive oxygen species. Rather high levels of the enzyme aggravate the damage caused under such conditions. Our work suggests that PPO's primary role is in defending plants against pathogens and herbivores. Jasmonate and ethylene, and apparently also salicylate, signals involved in responses to wounding and defense against herbivores and pathogens, enhance markedly and specifically the competence of chloroplasts to import and process pPPO. The interaction of the precursor with thylakoid membranes is primarily affected. The routing of PPO shows other unusual properties: stromal processing occurs in two sites, resulting in intermediates that are translocated across thylakoids by two different mechanisms - a DpH- and a Sec-dependent one. It is suggested that the dual pattern of processing and routing constitutes a'fail safe' mechanism, reflecting the need for a rapid and flexible response to defense challenges. Many of the observations described above should be taken into consideration when manipulation of PPO expression is contemplated for use in crop improvement.
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Sela, Hanan, Eduard Akhunov, and Brian J. Steffenson. Population genomics, linkage disequilibrium and association mapping of stripe rust resistance genes in wild emmer wheat, Triticum turgidum ssp. dicoccoides. United States Department of Agriculture, January 2014. http://dx.doi.org/10.32747/2014.7598170.bard.
Full textAbstract:
The primary goals of this project were: (1) development of a genetically characterized association panel of wild emmer for high resolution analysis of the genetic basis of complex traits; (2) characterization and mapping of genes and QTL for seedling and adult plant resistance to stripe rust in wild emmer populations; (3) characterization of LD patterns along wild emmer chromosomes; (4) elucidation of the multi-locus genetic structure of wild emmer populations and its correlation with geo-climatic variables at the collection sites. Introduction In recent years, Stripe (yellow) rust (Yr) caused by Pucciniastriiformis f. sp. tritici(PST) has become a major threat to wheat crops in many parts of the world. New races have overcome most of the known resistances. It is essential, therefore, that the search for new genes will continue, followed by their mapping by molecular markers and introgression into the elite varieties by marker-assisted selection (MAS). The reservoir of genes for disease and pest resistance in wild emmer wheat (Triticumdicoccoides) is an important resource that must be made available to wheat breeders. The majority of resistance genes that were introgressed so far in cultivated wheat are resistance (R) genes. These genes, though confering near-immunity from the seedling stage, are often overcome by the pathogen in a short period after being deployed over vast production areas. On the other hand, adult-plant resistance (APR) is usually more durable since it is, in many cases, polygenic and confers partial resistance that may put less selective pressure on the pathogen. In this project, we have screened a collection of 480 wild emmer accessions originating from Israel for APR and seedling resistance to PST. Seedling resistance was tested against one Israeli and 3 North American PST isolates. APR was tested on accessions that did not have seedling resistance. The APR screen was conducted in two fields in Israel and in one field in the USA over 3 years for a total of 11 replicates. We have found about 20 accessions that have moderate stripe rust APR with infection type (IT<5), and about 20 additional accessions that have novel seedling resistance (IT<3). We have genotyped the collection using genotyping by sequencing (GBS) and the 90K SNP chip array. GBS yielded a total 341K SNP that were filtered to 150K informative SNP. The 90K assay resulted in 11K informative SNP. We have conducted a genome-wide association scan (GWAS) and found one significant locus on 6BL ( -log p >5). Two novel loci were found for seedling resistance. Further investigation of the 6BL locus and the effect of Yr36 showed that the 6BL locus and the Yr36 have additive effect and that the presence of favorable alleles of both loci results in reduction of 2 grades in the IT score. To identify alleles conferring adaption to extreme climatic conditions, we have associated the patterns of genomic variation in wild emmer with historic climate data from the accessions’ collection sites. The analysis of population stratification revealed four genetically distinct groups of wild emmer accessions coinciding with their geographic distribution. Partitioning of genomic variance showed that geographic location and climate together explain 43% of SNPs among emmer accessions with 19% of SNPs affected by climatic factors. The top three bioclimatic factors driving SNP distribution were temperature seasonality, precipitation seasonality, and isothermality. Association mapping approaches revealed 57 SNPs associated with these bio-climatic variables. Out of 21 unique genomic regions controlling heading date variation, 10 (~50%) overlapped with SNPs showing significant association with at least one of the three bioclimatic variables. This result suggests that a substantial part of the genomic variation associated with local adaptation in wild emmer is driven by selection acting on loci regulating flowering. Conclusions: Wild emmer can serve as a good source for novel APR and seedling R genes for stripe rust resistance. APR for stripe rust is a complex trait conferred by several loci that may have an additive effect. GWAS is feasible in the wild emmer population, however, its detection power is limited. A panel of wild emmer tagged with more than 150K SNP is available for further GWAS of important traits. The insights gained by the bioclimatic-gentic associations should be taken into consideration when planning conservation strategies.
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Tzin, V., B. Dilkes, and H. Sela. Identifying molecular markers for defense metabolites against aphid feeding in wild emmer wheat. Israel: United States-Israel Binational Agricultural Research and Development Fund, 2021. http://dx.doi.org/10.32747/2021.8134174.bard.
Full textAbstract:
Bread wheat is the second most important food crop, providing calories to half of the world population and roughly one-fifth of the calories and protein consumed by people worldwide. Crop losses to insect pests depress yields and climate change is expected to significantly increase this problem. To combat global food insecurity, the protection of crops from insect pests must be prioritized. The Bird cherry-oat aphid, Rhopalosiphum padi, is the most abundant and economically important cereal pest, causes up to 40-60 % yield loss through direct feeding and vectoring plant diseases. The main goal of this project was to identify molecular markers associated with aphid resistance and defense metabolite levels in wild emmer wheat (WEW). During the three years of this project, we screened a large number of WEW accessions and conducted a genome-wide association study (GWAS) analysis. We experimented with data processing and explored different GWAS models, which revealed a massive number of determinants of aphid resistance and highlighted hundreds of single nucleotide polymorphisms (SNPs). Thus, we focused on a small subset of genes that linked to the most significant SNPs. By the end of this collaboration, we have a list of important SNPs, and three major genes that we believe have a strong effect on wheat resistance to aphids. Work on these genes is continuing and will soon publish our exciting new results.
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Ron, Eliora, and Eugene Eugene Nester. Global functional genomics of plant cell transformation by agrobacterium. United States Department of Agriculture, March 2009. http://dx.doi.org/10.32747/2009.7695860.bard.
Full textAbstract:
The aim of this study was to carry out a global functional genomics analysis of plant cell transformation by Agrobacterium in order to define and characterize the physiology of Agrobacterium in the acidic environment of a wounded plant. We planed to study the proteome and transcriptome of Agrobacterium in response to a change in pH, from 7.2 to 5.5 and identify genes and circuits directly involved in this change. Bacteria-plant interactions involve a large number of global regulatory systems, which are essential for protection against new stressful conditions. The interaction of bacteria with their hosts has been previously studied by genetic-physiological methods. We wanted to make use of the new capabilities to study these interactions on a global scale, using transcription analysis (transcriptomics, microarrays) and proteomics (2D gel electrophoresis and mass spectrometry). The results provided extensive data on the functional genomics under conditions that partially mimic plant infection and – in addition - revealed some surprising and significant data. Thus, we identified the genes whose expression is modulated when Agrobacterium is grown under the acidic conditions found in the rhizosphere (pH 5.5), an essential environmental factor in Agrobacterium – plant interactions essential for induction of the virulence program by plant signal molecules. Among the 45 genes whose expression was significantly elevated, of special interest is the two-component chromosomally encoded system, ChvG/I which is involved in regulating acid inducible genes. A second exciting system under acid and ChvG/Icontrol is a secretion system for proteins, T6SS, encoded by 14 genes which appears to be important for Rhizobium leguminosarum nodule formation and nitrogen fixation and for virulence of Agrobacterium. The proteome analysis revealed that gamma aminobutyric acid (GABA), a metabolite secreted by wounded plants, induces the synthesis of an Agrobacterium lactonase which degrades the quorum sensing signal, N-acyl homoserine lactone (AHL), resulting in attenuation of virulence. In addition, through a transcriptomic analysis of Agrobacterium growing at the pH of the rhizosphere (pH=5.5), we demonstrated that salicylic acid (SA) a well-studied plant signal molecule important in plant defense, attenuates Agrobacterium virulence in two distinct ways - by down regulating the synthesis of the virulence (vir) genes required for the processing and transfer of the T-DNA and by inducing the same lactonase, which in turn degrades the AHL. Thus, GABA and SA with different molecular structures, induce the expression of these same genes. The identification of genes whose expression is modulated by conditions that mimic plant infection, as well as the identification of regulatory molecules that help control the early stages of infection, advance our understanding of this complex bacterial-plant interaction and has immediate potential applications to modify it. We expect that the data generated by our research will be used to develop novel strategies for the control of crown gall disease. Moreover, these results will also provide the basis for future biotechnological approaches that will use genetic manipulations to improve bacterial-plant interactions, leading to more efficient DNA transfer to recalcitrant plants and robust symbiosis. These advances will, in turn, contribute to plant protection by introducing genes for resistance against other bacteria, pests and environmental stress.
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Sessa, Guido, and Gregory Martin. Role of GRAS Transcription Factors in Tomato Disease Resistance and Basal Defense. United States Department of Agriculture, 2005. http://dx.doi.org/10.32747/2005.7696520.bard.
Full textAbstract:
The research problem: Bacterial spot and bacterial speck diseases of tomato are causedby strains of Xanthomonas campestris pv. vesicatoria (Xcv) and Pseudomonas syringae pv.tomato (Pst), respectively. These bacteria colonize aerial parts of the plant and causesignificant losses in tomato production worldwide. Protection against Xcv and Pst bycultural practices or chemical control has been unsuccessful and there are only limitedsources of genetic resistance to these pathogens. In previous research supported in part byBARD IS-3237-01, we extensively characterized changes in tomato gene expression uponthe onset of spot and speck disease resistance. A remarkable finding of these studies wasthe inducibility in tomato leaves by both Xcv and Pst strains of genes encodingtranscriptional activator of the GRAS family, which has not been previously linked todisease resistance. Goals: Central goals of this research were to investigate the role of GRAS genes in tomatoinnate immunity and to assess their potential use for disease control.Specific objectives were to: 1. Identify GRAS genes that are induced in tomato during thedefense response and analyze their role in disease resistance by loss-of-function experiments.2. Overexpress GRAS genes in tomato and characterize plants for possible broad-spectrumresistance. 3. Identify genes whose transcription is regulated by GRAS family. Our main achievements during this research program are in three major areas:1. Identification of tomato GRAS family members induced in defense responses andanalysis of their role in disease resistance. Genes encoding tomato GRAS family memberswere retrieved from databases and analyzed for their inducibility by Pst avirulent bacteria.Real-time RT-PCR analysis revealed that six SlGRAS transcripts are induced during theonset of disease resistance to Pst. Further expression analysis of two selected GRAS genesshowed that they accumulate in tomato plants in response to different avirulent bacteria orto the fungal elicitor EIX. In addition, eight SlGRAS genes, including the Pst-induciblefamily members, were induced by mechanical stress in part in a jasmonic acid-dependentmanner. Remarkably, SlGRAS6 gene was found to be required for tomato resistance to Pstin virus-induced gene silencing (VIGS) experiments.2. Molecular analysis of pathogen-induced GRAS transcriptional activators. In aheterologous yeast system, Pst-inducible GRAS genes were shown to have the ability toactivate transcription in agreement with their putative function of transcription factors. Inaddition, deletion analysis demonstrated that short sequences at the amino-terminus ofSlGRAS2, SlGRAS4 and SlGRAS6 are sufficient for transcriptional activation. Finally,defense-related SlGRAS proteins were found to localize to the cell nucleus. 3. Disease resistance and expression profiles of transgenic plants overexpressing SlGRASgenes. Transgenic plants overexpressing SlGRAS3 or SlGRAS6 were generated. Diseasesusceptibility tests revealed that these plants are not more resistant to Pst than wild-typeplants. Gene expression profiles of the overexpressing plants identified putative direct orindirect target genes regulated by SlGRAS3 and SlGRAS6. Scientific and agricultural significance: Our research activities established a novel linkbetween the GRAS family of transcription factors, plant disease resistance and mechanicalstress response. SlGRAS6 was found to be required for disease resistance to Pstsuggesting that this and possibly other GRAS family members are involved in thetranscriptional reprogramming that takes place during the onset of disease resistance.Their nuclear localization and transcriptional activation ability support their proposed roleas transcription factors or co-activators. However, the potential of utilizing GRAS familymembers for the improvement of plant disease resistance in agriculture has yet to bedemonstrated.
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Harman, Gary E., and Ilan Chet. Enhancement of plant disease resistance and productivity through use of root symbiotic fungi. United States Department of Agriculture, July 2008. http://dx.doi.org/10.32747/2008.7695588.bard.
Full textAbstract:
The objectives of the project were to (a) compare effects ofT22 and T-203 on growth promotion and induced resistance of maize inbred line Mol7; (b) follow induced resistance of pathogenesis-related proteins through changes in gene expression with a root and foliar pathogen in the presence or absence of T22 or T-203 and (c) to follow changes in the proteome of Mol? over time in roots and leaves in the presence or absence of T22 or T-203. The research built changes in our concepts regarding the effects of Trichoderma on plants; we hypothesized that there would be major changes in the physiology of plants and these would be reflected in changes in the plant proteome as a consequence of root infection by Trichoderma spp. Further, Trichoderma spp. differ in their effects on plants and these changes are largely a consequence of the production of different elicitors of elicitor mixtures that are produced in the zone of communication that is established by root infection by Trichoderma spp. In this work, we demonstrated that both T22 and T-203 increase growth and induce resistance to pathogens in maize. In Israel, it was shown that a hydrophobin is critical for root colonization by Trichoderma strains, and that peptaibols and an expansin-like protein from Ttrichoderma probably act as elicitors of induced resistance in plants. Further, this fungus induces the jasmonate/ethylene pathway of disease resistance and a specific cucumber MAPK is required for transduction of the resistance signal. This is the first such gene known to be induced by fungal systems. In the USA, extensive proteomic analyses of maize demonstrated a number of proteins are differentially regulated by T. harzianum strain T22. The pattern of up-regulation strongly supports the contention that this fungus induces increases in plant disease resistance, respiratory rates and photosynthesis. These are all very consistent with the observations of effects of the fungus on plants in the greenhouse and field. In addition, the chitinolytic complex of maize was examined. The numbers of maize genes encoding these enzymes was increased about 3-fold and their locations on maize chromosomes determined by sequence identification in specific BAC libraries on the web. One of the chitinolytic enzymes was determined to be a heterodimer between a specific exochitinase and different endochitinases dependent upon tissue differences (shoot or root) and the presence or absence of T. harzianum. These heterodimers, which were discovered in this work, are very strongly antifungal, especially the one from shoots in the presence of the biocontrol fungus. Finally, RNA was isolated from plants at Cornell and sent to Israel for transcriptome assessment using Affymetrix chips (the chips became available for maize at the end of the project). The data was sent back to Cornell for bioinformatic analyses and found, in large sense, to be consistent with the proteomic data. The final assessment of this data is just now possible since the full annotation of the sequences in the maize Affy chips is just now available. This work is already being used to discover more effective strains of Trichoderma. It also is expected to elucidate how we may be able to manipulate and breed plants for greater disease resistance, enhanced growth and yield and similar goals. This will be possible since the changes in gene and protein expression that lead to better plant performance can be elucidated by following changes induced by Trichoderma strains. The work was in, some parts, collaborative but in others, most specifically transcriptome analyses, fully synergistic.
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Sessa, Guido, and Gregory Martin. A functional genomics approach to dissect resistance of tomato to bacterial spot disease. United States Department of Agriculture, January 2004. http://dx.doi.org/10.32747/2004.7695876.bard.
Full textAbstract:
The research problem. Bacterial spot disease in tomato is of great economic importance worldwide and it is particularly severe in warm and moist areas affecting yield and quality of tomato fruits. Causal agent of spot disease is the Gram-negative bacterium Xanthomonas campestris pv. vesicatoria (Xcv), which can be a contaminant on tomato seeds, or survive in plant debris and in association with certain weeds. Despite the economic significance of spot disease, plant protection against Xcvby cultural practices and chemical control have so far proven unsuccessful. In addition, breeding for resistance to bacterial spot in tomato has been undermined by the genetic complexity of the available sources of resistance and by the multiple races of the pathogen. Genetic resistance to specific Xcvraces have been identified in tomato lines that develop a hypersensitive response and additional defense responses upon bacterial challenge. Central goals of this research were: 1. To identify plant genes involved in signaling and defense responses that result in the onset of resistance. 2. To characterize molecular properties and mode of action of bacterial proteins, which function as avirulence or virulence factors during the interaction between Xcvand resistant or susceptible tomato plants, respectively. Our main achievements during this research program are in three major areas: 1. Identification of differentially expressed genes during the resistance response of tomato to Xcvrace T3. A combination of suppression subtractive hybridization and microarray analysis identified a large set of tomato genes that are induced or repressed during the response of resistant plants to avirulent XcvT3 bacteria. These genes were grouped in clusters based on coordinate expression kinetics, and classified into over 20 functional classes. Among them we identified genes that are directly modulated by expression of the type III effector protein AvrXv3 and genes that are induced also during the tomato resistance response to Pseudomonas syringae pv. tomato. 2. Characterization of molecular and biochemical properties of the tomato LeMPK3MAP kinase. A detailed molecular and biochemical analysis was performed for LeMPK3 MAP kinase, which was among the genes induced by XcvT3 in resistant tomato plants. LeMPK3 was induced at the mRNA level by different pathogens, elicitors, and wounding, but not by defense-related plant hormones. Moreover, an induction of LeMPK3 kinase activity was observed in resistant tomato plants upon Xcvinfection. LeMPK3 was biochemically defined as a dual-specificity MAP kinase, and extensively characterized in vitro in terms of kinase activity, sites and mechanism of autophosphorylation, divalent cation preference, Kₘand Vₘₐₓ values for ATP. 3. Characteriztion of molecular properties of the Xcveffector protein AvrRxv. The avirulence gene avrRxvis involved in the genetic interaction that determines tomato resistance to Xcvrace T1. We found that AvrRxv functions inside the plant cell, localizes to the cytoplasm, and is sufficient to confer avirulence to virulent Xcvstrains. In addition, we showed that the AvrRxv cysteine protease catalytic core is essential for host recognition. Finally, insights into cellular processes activated by AvrRxv expression in resistant plants were obtained by microarray analysis of 8,600 tomato genes. Scientific and agricultural significance: The findings of these activities depict a comprehensive and detailed picture of cellular processes taking place during the onset of tomato resistance to Xcv. In this research, a large pool of genes, which may be involved in the control and execution of plant defense responses, was identified and the stage is set for the dissection of signaling pathways specifically triggered by Xcv.
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Mawassi, Munir, Adib Rowhani, Deborah A. Golino, Avichai Perl, and Edna Tanne. Rugose Wood Disease of Grapevine, Etiology and Virus Resistance in Transgenic Vines. United States Department of Agriculture, November 2003. http://dx.doi.org/10.32747/2003.7586477.bard.
Full textAbstract:
Rugose wood is a complex disease of grapevines, which occurs in all growing areas. The disease is spread in the field by vector transmission (mealybugs). At least five elongated-phloem- limited viruses are implicated in the various rugose wood disorders. The most fully characterized of these are Grapevine virus A (GV A) and GVB, members of a newly established genus, the vitivirus. GVC, a putative vitivirus, is much less well characterized than GV A or GVB. The information regarding the role of GVC in the etiology and epidemiology of rugose wood is fragmentary and no sequence data for GVC are available. The proposed research is aimed to study the etiology and epidemiology of rugose wood disease, and to construct genetically engineered virus-resistant grapevines. The objectives of our proposed research were to construct transgenic plants with coat protein gene sequences designed to induce post-transcriptional gene silencing (pTGS); to study the epidemiology and etiology of rugose wood disease by cloning and sequencing of GVC; and surveying of rugose wood- associated viruses in Californian and Israeli vineyards. In an attempt to experimentally define the role of the various genes of GV A, we utilized the infectious clone, inserted mutations in every ORF, and studied the effect on viral replication, gene expression, symptoms and viral movement. We explored the production of viral RNAs in a GV A-infected Nicotiana benthamiana herbaceous host, and characterized one nested set of three 5'-terminal sgRNAs of 5.1, 5.5 and 6.0 kb, and another, of three 3'-terminal sgRNAs of 2.2, 1.8 and 1.0 kb that could serve for expression of ORFs 2-3, respectively. Several GV A constructs have been assembled into pCAMBIA 230 I, a binary vector which is used for Angrobacterium mediated transformation: GV A CP gene; two copies of the GV A CP gene arranged in the same antisense orientation; two copies of the GV A CP gene in which the downstream copy is in an antigens orientation; GV A replicase gene; GV A replicase gene plus the 3' UTR sequence; and the full genome of GV A. Experiments for transformation of N. benthamiana and grapevine cell suspension with these constructs have been initiated. Transgenic N. benthamiana plants that contained the CP gene, the replicase gene and the entire genome of GV A were obtained. For grapevine transformation, we have developed efficient protocols for transformation and successfully grapevine plantlets that contained the CP gene and the replicase genes of GV A were obtained. These plants are still under examination for expression of the trans genes. The construction of transgenic plants with GV A sequences will provide, in the long run, a means to control one of the most prevalent viruses associated with grapevines. Our many attempts to produce a cDNA library from the genome of GVC failed. For surveying of rugose wood associated viruses in California vineyards, samples were collected from different grape growing areas and tested by RT-PCR for GV A, GVB and GVD. The results indicated that some of the samples were infected with multiple viruses, but overall, we found higher incidence of GVB and GV A infection in California vineyards and new introduction varieties, respectively. In this research we also conducted studies to increase our understanding of virus - induced rootstock decline and its importance in vineyard productivity. Our results provided supporting evidence that the rootstock response to virus infection depends on the rootstock genotype and the virus type. In general, rootstocks are differ widely in virus susceptibility. Our data indicated that a virus type or its combination with other viruses was responsible in virus-induced rootstock decline. As the results showed, the growth of the rootstocks were severely affected when the combination of more than one virus was present.