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Статті в журналах з теми "3108 Plant biology":
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Chiykowski, L. N. "BIOLOGY AND REARING OF PARAPHLEPSIUS IRRORATUS (HOMOPTERA: CICADELLIDAE), A VECTOR OF PEACH X-DISEASE." Canadian Entomologist 117, no. 6 (June 1985): 717–26. http://dx.doi.org/10.4039/ent117717-6.
Анотація:
AbstractA method of rearing Paraphlepsius irroratus (Say) under artificial conditions was developed by using a leguminous plant species as the oviposition host and a gramineous species as the food plant for nymphs. Nymphs completed their development on all 10 gramineous species tested. Total time for completion of the 5 nymphal instars ranged from 31.8 to 59.2 days, depending on the plant species used. With the exception of Alopecurus pratensis, all monocotyledonous species tested were found to be suitable food plants for nymphs, allowing 50% or more of the insects to survive for 3 weeks or more. Only 5 dicotyledonous species supported a similar survival level of nymphs. Adult survival remained above the 50% level on Apium graveolans var. dulce, 6 members of the Leguminosae, and all members of Composite with the exception of Callistephus chinensis. Survival of adult leafhoppers on monocotyledons was relatively high after 1 week but considerable mortality followed longer confinement. Although nymphs emerged from eggs laid on a wide range of plant species, the numbers recorded on monocotyledons suggest that monocots are important as oviposition hosts for P. irroratus in nature.
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Weston, Leslie A., Jacob N. Barney, and Antonio DiTommaso. "A Review of the Biology and Ecology of Three Invasive Perennials in New York State: Japanese Knotweed (Polygonum cuspidatum), Mugwort (Artemisia vulgaris) and Pale Swallow-wort (Vincetoxicum rossicum)." Plant and Soil 277, no. 1-2 (December 2005): 53–69. http://dx.doi.org/10.1007/s11104-005-3102-x.
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Yamada, Masashi, Nobuyasu Matsuura, Hiroto Suzuki, Chihiro Kurosaka, Naoko Hasegawa, Makato Ubukata, Toshiyuki Tanaka, and Munekazu Iinuma. "Corrigendum to “Germacranolides from Calea urticifolia” [Phytochem. 65 (2004) 3107–3111]." Phytochemistry 66, no. 15 (August 2005): 1864. http://dx.doi.org/10.1016/j.phytochem.2005.05.014.
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Chan, Charlotte R., and Robert D. Marquard. "Horticultural Research at The Holden Arboretum." HortScience 31, no. 4 (August 1996): 627e—627. http://dx.doi.org/10.21273/hortsci.31.4.627e.
Анотація:
The Holden Arboretum, established in 1931, is the largest arboretum in the United States. Its mission is to promote the knowledge and appreciation of plants for personal enjoyment, inspiration, and recreation; for scientific research; and for educational and aesthetic purposes. Of the Arboretum's 3100 acres, 800 acres support collections and display gardens, while the balance comprise natural areas. The collections include nearly 8,000 accessions from 76 plant families; about 700 plant species, some rare or endangered, occupy the natural areas. The education component of the mission connects the Arboretum with the public through school programs, classes, horticultural therapy, and seasonal internships. Two research fellowships are also available. The Holden Arboretum has expanded the research emphasis. The David G. Leach Research Station, part of the Arboretum since 1986, focuses on rhododendron and magnolia breeding and research. Built in 1993, the Horticulture Science Center is a modern research and production facility able to more fully implement and support a broad range of formal horticultural research. The main objective of the research program is to develop superior woody ornamentals for the landscape through hybridization. Additional research emphasizes reproductive biology and using biochemical markers (isozymes and RAPDs) to answer basic questions about the genera under study (Aesculus, Hamamelis, Cercis).
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Djurovic, Sanja, Vesna Dragicevic, Hadi Waisi, Maja Pagnacco, Nevena Lukovic, Zorica Knezevic-Jugovic, and Bogdan Nikolic. "Enhancement of antioxidant activity and bioactive compound contents in yellow soybean by plant-extract-based products." Archives of Biological Sciences 71, no. 3 (2019): 425–34. http://dx.doi.org/10.2298/abs190123024d.
Анотація:
Polyphenols present in different plant cell organelles increase the resistance of plants to various types of environmental stresses. We investigated the possibility of increasing the content of bioactive compounds in the seed of yellow soybean variety Laura. The soybean was treated during vegetation with five products based on plant extracts, on the assumption of enrichment of plants with various nutrients. Soybean flour extracts were screened spectrophotometrically for total phenolic content and antioxidant activity. The antioxidant activity was evaluated using three methods. The content of phenolic acids was determined by HPLC, and the raw protein content was estimated by the Kjeldahl method. Depending on the treatment, variations in the quantity of individual phenolic acids with up to 90% higher concentration as compared to the control were observed. Controlled usage of certain plant extracts can increase the concentration of the target group of bioactive compounds in the samples. The synergistic effect of proteins and phenolic compounds on the antioxidant activity of extracts was detected. The results of this study are not only important from the aspect of plant resistance to various types of stress, but also when considering soybean as a functional food. [Projects of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 31018, Grant no. 31037, Grant no. 37021 and Grant no. 172015]
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Huang, Yuanyuan, Zhansheng Wu, Yanhui He, Bang-Ce Ye, and Chun Li. "RhizosphericBacillus subtilisExhibits Biocontrol Effect againstRhizoctonia solaniin Pepper(Capsicum annuum)." BioMed Research International 2017 (2017): 1–9. http://dx.doi.org/10.1155/2017/9397619.
Анотація:
This study aimed at evaluating the ability of SL-44 to controlRhizoctonia solaniand promote pepper(Capsicum annuum)growth. Strain SL-44 was isolated from plant rhizosphere and the pot experiment results indicated that the dry and fresh weights of pepper in SL-44 andRhizoctonia solani(S-R) treatment were 45.5% and 54.2% higher than those inRhizoctonia solani(R) treatment and 18.2% and 31.8% higher than those in CK (control, noninoculation) treatment. The plant height in S-R treatment increased by 14.2% and 9.0% compared with those in the R and CK treatments, respectively. In vitro antagonism assay showed that SL-44 exhibited strong antifungal activity against the mycelial growth ofRhizoctonia solani, with an inhibition rate of 42.3%. The amount of phosphorus dissolved by SL-44 reached 60.58 mg·L−1in broth and 7.5 μg·mL−1IAA were secreted by SL-44. Strain SL-44 inhibited the growth ofR. solaniand improved biomass of pepper plants. Mass exchange and information transmission between the pepper plants and SL-44 mutually promoted their development.Bacillus subtilisSL-44 has a great potential as biocontrol agent againstRhizoctonia solanion pepper plants.
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Peterson, Richard B. "PsbS genotype in relation to coordinated function of PS II and PS I in Arabidopsis leaves." Photosynthesis Research 85, no. 2 (August 2005): 205–19. http://dx.doi.org/10.1007/s11120-005-3106-7.
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Gennis, Robert B. "Respiration in Archaea and Bacteria: Diversity of Prokaryotic Electron Transport Carriers. Davide Zannoni, Advances in Photosynthesis and Respiration (Series Editor, Govindjee), Kluwer Academic Publishers, Dordrecht, The Netherlands, Volume 15, 2004, 350 pp, ISBN 1-4020-2001-5, Price EUR 175.00, USD 193.00, GBP 121.00." Photosynthesis Research 83, no. 3 (March 2005): 363–64. http://dx.doi.org/10.1007/s11120-005-3107-6.
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Nair, N., D. Plant, J. Isaacs, A. Morgan, K. Hyrich, A. Barton, and A. G. Wilson. "AB0011 DNA METHYLATION AS A BIOMARKER OF TOCILIZUMAB RESPONSE IN RHEUMATOID ARTHRITIS PATIENTS." Annals of the Rheumatic Diseases 81, Suppl 1 (May 23, 2022): 1141.1–1141. http://dx.doi.org/10.1136/annrheumdis-2022-eular.3102.
Анотація:
BackgroundTocilizumab (TCZ) is a disease-modifying antirheumatic biologic drug, which targets the IL-6 signalling pathway and is effective in ameliorating disease activity in rheumatoid arthritis (RA). However, approximately 50% of patients do not respond adequately to TCZ and some patients report adverse events. Considering there is growing evidence that DNA methylation is implicated in RA susceptibility and response to some biologics (1, 2), we investigated DNA methylation as a candidate biomarker for response to TCZ in RA.ObjectivesTo identify differential DNA methylation signatures in whole blood associated with TCZ response in patients with RA.MethodsEpigenome-wide DNA methylation patterns were measured using the Infinium EPIC 850k BeadChip (Illumina) in whole blood-derived DNA samples from patients with RA. DNA was extracted from blood samples taken pre-treatment and following 3 months on therapy, and response was determined at 6 months using the Clinical Disease Activity Index (CDAI). Patients who had good response (n=10) or poor response (n=10) to TCZ by 6 months were selected. Samples from secondary poor responders (n=10) (patients who had an improvement of CDAI and were in remission at 3 months, followed by a worsening of CDAI at 6 months) were also analysed. Differentially methylated positions (DMPs) were identified using linear regression, adjusting for gender, age, cell composition, smoking status, and glucocorticoid use.ResultsIn the pre-treatment samples, 20 DMPs were significantly associated with response status at 6 months (unadjusted p-value <10-6), whilst in the 3 month samples, 21 DMPs were associated with response. One DMP, cg03121467, was significantly less methylated in good responders compared to poor responders in the pre-treatment samples. This DMP is close to EPB41L4A and may play a role in β–catenin signalling. Interestingly, cg10136146 was significantly less methylated in secondary poor responders compared to both good and poor responders in the 3 month samples. This DMP maps close to CD81, which plays a role in mediating the development and activation of B and T lymphocytes.ConclusionThese preliminary results provide evidence that DNA methylation patterns may predict response to TCZ. Further regional and pathway analyses is in progress and validation of these findings in other larger data sets is required.References[1]Liu,Y., Aryee,M.J., Padyukov,L., Fallin,M.D., Hesselberg,E., Runarsson,A., Reinius,L., Acevedo,N., Taub,M., Ronninger,M., et al. (2013) Epigenome-wide association data implicate DNA methylation as an intermediary of genetic risk in rheumatoid arthritis. Nat. Biotechnol., 31, 142–147.[2]Plant,D., Webster,A., Nair,N., Oliver,J., Smith,S.L., Eyre,S., Hyrich,K.L., Wilson,A.G., Morgan,A.W., Isaacs,J.D., et al. (2016) Differential Methylation as a Biomarker of Response to Etanercept in Patients With Rheumatoid Arthritis. Arthritis Rheumatol. (Hoboken, N.J.), 68, 1353–60.Disclosure of InterestsNisha Nair: None declared, Darren Plant: None declared, John Isaacs Speakers bureau: Abbvie, Gilead, Roche, UCB, Grant/research support from: GSK, Janssen, Pfizer, Ann Morgan Speakers bureau: Roche/Chugai, Consultant of: GSK, Roche, Chugai, AstraZeneca, Regeneron, Sanofi, Vifor, Grant/research support from: Roche, Kiniksa Pharmaceuticals, Kimme Hyrich Consultant of: AbbVie, Grant/research support from: Pfizer, BMS, Anne Barton Grant/research support from: I have received grant funding from Pfizer, Galapagos, Scipher Medicine and Bristol Myers Squibb., Anthony G Wilson: None declared
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Keerthana, K., S. Chitra, and T. Naveenkumar. "Screening of finger millet genotypes for sodicity tolerance using the Na+/K+ ratio as a major physiological trait." Journal of Applied and Natural Science 14, SI (July 15, 2022): 73–76. http://dx.doi.org/10.31018/jans.v14isi.3571.
Анотація:
Sodicity affects a larger area than salinity, but research on the sodicity tolerance mechanism is limited. The study was carried out to screen 120 finger millet genotypes under sodic soil conditions and identify sodicity-tolerant genotypes. The experimental field soil conditions were sandy clay loam with pH 8.9, electrical conductivity (EC) 0.94 dSm-1 and exchangeable sodium percentage (ESP) 21.5, which was naturally sodic. Grain yield per plant and Na+/K+ ratio were recorded for each genotype to screen sodicity tolerance among the genotypes. A significantly higher grain yield per plant than that of the sodicity-tolerant check variety TRY 1 (23.10 g) was observed in 30 finger millet genotypes. The analysis of sodium and potassium revealed that these 30 finger millet genotypes also recorded a significantly lower Na+/K+ ratio, which is comparatively lower than that of the sodicity-tolerant check variety TRY 1 (0.23 Na+/K+ ratio). The genotypes (FIN 3045, FIN 2875, FIN 3077, FIN 3015, FIN 3063, FIN 2861, FIN 3028, FIN 2867, FIN 2854, FIN 2860, FIN 2872, FIN 2896, FIN 4268, FIN 3034, FIN 3928, FIN 3104, FIN 3965, FIN 3091, FIN 2960, FIN 3994, FIN 4198, FIN 3174, FIN 3078, FIN 4288, FIN 4202, FIN 4238, FIN 3089, FIN 4205, FIN 3966 and FIN 3182) that recorded higher grain yield per plant and lower Na+/K+ ratio can be considered sodicity tolerant. These genotypes with a high grain yield per plant and a low Na+/K+ ratio could be utilized in stress breeding programs to develop sodicity-tolerant finger millet varieties.
Дисертації з теми "3108 Plant biology":
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Radermacher, Astrid Lillie. "Desiccation-driven senescence in the resurrection plant Xerophyta schlechteri (Baker) N.L. Menezes." Doctoral thesis, Faculty of Science, 2019. https://hdl.handle.net/11427/31708.
Анотація:
Drought-induced senescence is a degenerative process that involves the degradation of cellular metabolites and photosynthetic pigments and uncontrolled dismantling of cellular membranes and organelles. Angiosperm resurrection plants display vegetative desiccation tolerance and avoid drought-induced senescence in most of their tissues. Developmentally older tissues, however, fail to recover during rehydration and ultimately senesce. Comparison of the desiccation-associated responses of older senescent tissues (ST) with non-senescent tissues (NST) will allow for understanding of mechanisms promoting senescence in the former and prevention of senescence in the latter. In the monocotyledonous resurrection plant Xerophyta schlechteri (Baker) N.L.Menezes, leaf tips senesce following desiccation, whereas the rest of the leaf blade survives. This study characterised structural, metabolic and transcriptional changes in ST and NST at varying water contents during desiccation and rehydration. Light and transmission electron microscopy was used to follow anatomical and subcellular responses, and metabolic differences were studied using gas chromatography-mass spectrometry and colorimetric metabolite assays. These results show that drying below 35% relative water content (0.7 gH2O/g dry mass) in ST resulted in the initiation of age-related senescence hallmarks and that these tissues continue this process after rehydration. Analysis of the transcriptome was done using RNA-Seq, which was subject to differential expression analysis and network analysis to elucidate the potential mechanisms for senescence regulation in this species. Significantly increased transcription of senescence associated genes was observed in the air dry sampling point, indicating that initiation of cellular death occurred below 20% RWC. Network analysis based on Pearson correlation revealed a high degree of clustering of these genes, suggesting co-regulation. The majority of these genes had two enriched motifs in their upstream regions, identified as binding sites for WRKY and other transcription factors. A model integrating these observations is presented, with insights into how senescence is initiated in ST and repressed in NST.
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Audam, Timothy Ndagi. "Characterization of SIP470, a Family 1 Lipid Transfer Protein and its Role in Plant Stress Signaling." Digital Commons @ East Tennessee State University, 2016. https://dc.etsu.edu/etd/3103.
Анотація:
SIP470, a putative tobacco lipid transfer protein, was identified in a yeast two-hybrid screen to interact with SABP2. SABP2 is a critical role in SA-mediated signaling in tobacco and other plants. In vitro studies using purified recombinant SIP470 confirmed that it is a lipid binding protein. In an attempt to determine its role in mediating stress responses, Arabidopsis T-DNA insertion knockout lines lacking SIP470 homolog were used for the analysis. These mutant plants were defective in basal resistance against microbial pathogens. Expression of defense gene PR-1 was also delayed in these mutant plants. Interestingly, these mutant plants were not defective in inducing systemic acquired resistance. Besides biotic stress, these mutant plants also showed increased susceptibility to abiotic stresses. To directly study the role of SIP470 in tobacco plants, transgenic tobacco lines, with reduced levels of SIP470 expression, were generated using RNAi and transgenic lines overexpressing SIP470 were also generated.
3
Schubert, Axel. "Studying nonlinear optical properties of the plant light harvesting protein LHCII." Doctoral thesis, [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=972710507.
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Cincu, Emilia. "Regulation of mitochondrial gene copy number in plants and the influence of impaired chloroplast function on mitochondrial motility." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2014. http://dx.doi.org/10.18452/17192.
Анотація:
Das mitochondriale Genom der Pflanze weist mit einer heterogenen Population linearer, häufig auch verzweigten und zusätzlichen kleineren, zirkulären Molekülen eine komplexe Struktur auf. Um Einblicke in die mitochondrialen Genkopienzahl und deren Regulation sowohl unter normalen als auch unter Stressbedingungen zu erhalten, wurde die Kopienzahl pro Zelle vier repräsentativer Gene mittels qRT-PCR und Durchflusszytometrie ermittelt. Die Bestimmung der mitochondrialen Genkopienzahl in unterschiedlichen Spezies sowie in Organen der Modellpflanze Arabidopsis thaliana zeigte, dass die Kopienzahl mitochondrialer Gene sich nicht nur in den unterschiedlichen Spezies, sondern auch zwischen den unterschiedlichen Organen unterschied, wobei die höchsten Werte in der Wurzelspitze erreicht wurden. In Arabidopsis Keimlingen, welche zur Unterdrückung der plastidären Translation auf Spectinomycin-haltigem Medium angezogen wurden, wurde im Vergleich zu Kontrollpflanzen ein dreifacher Anstieg der Genkopienzahl festgestellt. Dieser Effekt erwies sich als spezifisch für Blatt- bzw. Kotyledonengewebe und warr unabhängig vom Licht. Mutanten mit Defekten in der Respiration zeigten ebenfalls erhöhte Genkopienzahlen, die durch Anzucht der Pflanzen auf Spectinomycin noch erhöht werden konnten. Dieses Ergebnis legt ein komplexes, regulatorisches Netzwerk nahe, in welchem sowohl Respiration als auch Photosynthese die Aufrechterhaltung einer stabilen Genkopienzahl innerhalb der Pflanzenzelle beeinflussen. Die Untersuchungen einer Spectinomycin-behandelter mt-GFP Arabidopsis Pflanzenlinie mittels CLSM zeigten einen Stillstand der Motilität der Mitochondrien in den epidermalen Zellen der weißen Kotyledonen, obwohl eine TEM Analyse eine normale, interne Morphologie ergab. Weitere Untersuchungen führten zu der Schlussfolgerung, dass es auch hier die Stärke der plastidären Beeinträchtigung, welche zu einem gelb-weißen Phänotyp führt, für den Arrest der Mobilität verantwortlich ist.The plant mitochondrial genome has a complex structure. It exists in the form of a heterogeneous population of linear, often branched molecules with smaller than genome-size circular molecules being present in low abundance. In order to study the mitochondrial genome abundance and its regulation in plants under both standard and stress conditions, we determined the gene copy number of four representative mitochondrial genes using quantitative real-time PCR and flow-cytometry. Determination of mitochondrial gene copy number in different plant species and in organs of the model plant Arabidopsis thaliana showed that the copy number of the four investigated genes varied between species and also between different organs, having the highest values in the root tips. The growth of Arabidopsis seedlings on MS medium containing spectinomycin (a plastid translation inhibitor) led to a three-fold increase in the copy number in white versus green seedlings, an effect that is leaf/cotyledon specific and light-independent. Respiration deficient mutants also showed an increase in the gene copy number, this effect being further amplified when the mutants were grown on spectinomycin. The data suggest a complex regulatory network in which both photosynthesis and respiration influence the maintenance of a stable mitochondrial gene copy number within plant cells. CLSM investigations of a spectinomycin-treated mt-GFP line showed that in epidermal cells of white cotyledons most of the mitochondria are not motile with TEM analysis presenting normal internal morphology. Further investigations led to the conclusion that the threshold level of chloroplast impairment that leads to a motility arrest is represented by the appearance of a yellow-white cotyledon phenotype. These results point to a new regulatory mechanism of mitochondrial dynamics that is directly influenced by impaired chloroplast development under standard growth conditions.
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Kühn, Kristina. "Analysis of components of the mitochondrial transcription machinery in Arabidopsis thaliana." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2006. http://dx.doi.org/10.18452/15453.
Анотація:
In der vorliegenden Arbeit wurde die Transkription mitochondrialer Gene durch die kernkodierten Phagentyp-RNA-Polymerasen RpoTm und RpoTmp der Pflanze Arabidopsis untersucht. Im Mitochondriengenom von Arabidopsis wurden f r 12 Gene Promotoren bestimmt. Diese zeigten verschiedene Sequenzelemente und wichen meist von der f r Dikotyle publizierten Konsensussequenz ab. F r die Mehrheit der Gene wurden multiple Promotoren identifiziert. Es wurden weiterhin Promotoren nachgewiesen, welche die Transkription vermutlich nicht funktioneller Sequenzen aktivieren. Architektur, Lokalisation und Nutzung mitochondrialer Promotoren implizieren eine wenig stringente Kontrolle der Transkriptionsinitiation in Arabidopsis-Mitochondrien. Zur Analyse der Funktionen von RpoTm und RpoTmp wurde ein in vitro-Transkriptionssystem entwickelt. Da RpoT-Enzyme m”glicherweise Kofaktoren ben”tigen, wurde in Arabidopsis nach Genen potentieller mitochondrialer Transkriptionsfaktoren gesucht. Als mitochondriales Protein mit Žhnlichkeit zu mtTFB, einem essentiellen Transkriptionsfaktor in Hefemitochondrien, wurde MetA identifiziert. In in vitro-Assays initiierte RpoTm an verschiedenen Promotoren die Transkription, w„hrend RpoTmp keine signifikante Promotorspezifit„t zeigte. Die spezifische Promotornutzung durch RpoTm erforderte superhelikale DNA. Weder RpoTm noch RpoTmp wurde durch MetA stimuliert. Eine mtTFB-„hnliche Funktion von MetA ist daher unwahrscheinlich. F r MetA wurde ausserdem eine engere phylogenetische Beziehung zu nukle„ren rRNA-Dimethylasen als zu mtTFB ermittelt. Die hier vorgestellten Studien belegen die Transkription mitochondrialer Gene in Arabidopsis durch RpoTm; f r RpoTmp ist eine nicht-redundante Transkriptionsfunktion denkbar. Die Kofaktor-unabh„ngige Spezifit„t von RpoTm f r verschiedene Promotoren und die wenig stringente Initiationskontrolle in vivo legen nahe, dass eine individuelle Regulation mitochondrialer Gene in Arabidopsis auf Transkriptionsebene nicht erfolgt.Mitochondria depend on a nucleus-encoded transcription machinery to express their genome. The present study examined the transcription of mitochondrial genes by two nucleus-encoded phage-type RNA polymerases, RpoTm and RpoTmp, in the plant Arabidopsis. For selected mitochondrial genes in Arabidopsis, transcription initiation sites were determined. Most genes were found to possess multiple promoters. The identified promoters displayed diverse sequence elements and mostly deviated from a nonanucleotide consensus derived previously for dicot mitochondrial promoters. Several promoters were detected that activate transcription of presumably non-functional sequences. Promoter architecture, distribution and utilization suggest a non-stringent control of transcription initiation in Arabidopsis mitochondria. An in vitro transcription system was set up to elucidate the roles of RpoTm and RpoTmp. Since RpoT enzymes possibly require auxiliary factors, the Arabidopsis genome was screened for potential cofactors of phage-type RNA polymerases. A mitochondrial protein (MetA) with similarity to mtTFB, an essential transcription factor in yeast mitochondria, was identified. In in vitro transcription studies, RpoTm recognized various promoters whereas RpoTmp displayed no significant promoter specificity. Promoter recognition by RpoTm depended on supercoiled DNA templates. Transcription initiation by RpoTm or RpoTmp was not affected by MetA, indicating that MetA is not functionally equivalent to mtTFB. Besides, MetA was found to be more closely related to non-mitochondrial rRNA dimethylases than to mtTFB. The present study establishes RpoTm to transcribe mitochondrial genes; RpoTmp may have a non-overlapping transcriptional role in mitochondria. The cofactor-independent promoter specificity of RpoTm and the apparently non-stringent control of transcription initiation in vivo imply that mitochondrial genes in Arabidopsis may not be regulated individually at the transcriptional level.
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Roca, Ferrerfábrega María Dolores. "Absorción de nitrato en cultivo sin suelo. Estudio de las implicaciones agronómicas y fisiológicas como base para optimizar el manejo de la fertilización. Aplicación a un cultivo de rosas." Doctoral thesis, Editorial Universitat Politècnica de València, 2009. http://hdl.handle.net/10251/6474.
Анотація:
La integración de la técnica de cultivo sin suelo en el sistema invernadero permite optimizar tanto el ambiente de las raíces - responsables de los procesos de absorción de agua y elementos minerales disueltos en ella -, como los ajustes de sus aportes en función de la demanda de la planta a escala de minutos. En tiempos cortos, las demandas hídricas y de minerales (N-NO3-) son asincrónicas. Las tasas de absorción son variales, y los factores que le afectan son múltiples. La obtención de modelos de estimación de la demanda mineral (NO3) a escala horaria en función de parámetros fácilmente medibles en los sistemas de producción invernadero-CSS - como los climáticos - o estimables - como la demanda hídrica, es uno de los objetivos principales de este estudio, el cual se realiza sobre un cultivo-modelo, el rosal para flor cortada de producción continua, bajo condiciones comerciales de producción, las cuales han adoptado el cultivo sin suelo recirculante cuya mejora merece ser atendida. La absorción mineral depende de la energía procedente de la oxidación de los asimilados en las raíces que son traslocados desde la parte aérea fotosintética. Se ha considerado el manejo de la parte aérea adoptado por el cultivador, en el que se distinguen dos compartimientos, uno creado mediante el arqueado de tallos no comerciales, cuya función es la generación permanente de asimilados, y otro que son los tallos florales que cuando alcanzan su estado de madurez fotosintética, son recolectados. Se producen variaciones estacionales de las relaciones fuente/sumidero y de las fuerzas de sumidero entre la cosecha y las raíces, que afectan a la absorción mineral.Roca Ferrerfábrega, MD. (2009). Absorción de nitrato en cultivo sin suelo. Estudio de las implicaciones agronómicas y fisiológicas como base para optimizar el manejo de la fertilización. Aplicación a un cultivo de rosas [Tesis doctoral]. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/6474
Palancia
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Collins, Daniel. "A HPLC-ESI-MS/MS Study of Hydroxybenzoic Acids and Related Derivatives in Commercial Seaweed Biostimulants and their Plant Growth Bioactivity." Thesis, 2022. https://vuir.vu.edu.au/44693/.
Анотація:
The rapidly growing world population, increasing severity of climate change, and constantly evolving environmental pressures have drawn into question whether current agricultural practices can meet the growing food demands healthily, equitably and sustainably. This has resulted in the rising popularity of natural biostimulants, particularly seaweed extracts, to increase crop productivity in an eco-friendly and safe manner. To better understand the complex modes of action underpinning the well-reported benefits of seaweed biostimulants to crops, their phytochemical composition requires further characterisation. Hydroxybenzoic acids, a subclass of phenolic acids, are an important class of phytochemicals and the aim of this study was to characterise their profile in commercial seaweed biostimulants. This work used modern analytical technologies to investigate salicylic acid and other benzoic acid derivatives in a commercial seaweed biostimulant, and then assessed the biological activity of the monohydroxybenzoic acids using plant growth assays.
Qualitative HPLC-ESI-MS/MS methods were developed for the analysis of hydroxybenzoic acids and related derivatives. The various benzoic acid derivatives investigated include monohydroxybenzoic acids, dihydroxybenzoic acids, trihydroxybenzoic acids, methoxylated hydroxybenzoic acids, methoxylated benzoic acids, and an amino substituted benzoic acid. The HPLC-ESI-MS/MS methods for the analysis of the various derivatives were then employed to investigate the presence of these compounds in the commercial seaweed biostimulant. The compounds found to be present were the monohydroxybenzoic acids, 2,3- and 3,4-dihydroxybenzoic acid, syringic acid, and anthranilic acid.
A HPLC-ESI-MS/MS method for the analysis of the monohydroxybenzoic acids was optimised and partially validated for the quantification of salicylic acid and its isomers in a commercial seaweed biostimulant. Sample preparation employed acidified acetonitrile partitioning of the seaweed biostimulant before mixed-mode solid-phase extraction. The three isomers were successfully separated using a reversed-phase biphenyl stationary phase with a methanol/water mobile phase acidified with formic acid. The MS/MS detection employed the characteristic MRM transition of m/z 137 93 of the monohydroxybenzoic acids. The concentrations of 2-, 3- and 4-hydroxybenzoic acid in a commercial seaweed biostimulant were found to be 137, 3409, and 1748 μg/L, respectively.
Tomato seedling plant growth bioassays were conducted to investigate the biological effects of salicylic acid and its isomers on plant growth. Fresh and dry root and shoot weight data along with longest root length data were assessed to evaluate the biological effects of the various treatments on tomato seedling growth. It was found that a significant increase in root growth was observed when the commercial seaweed biostimulant was fortified with a combination of the three monohydroxybenzoic acids, using dosages that correlate to the concentrations determined in the seaweed biostimulant in this study.
Книги з теми "3108 Plant biology":
1
Bajwa, Ali Ahsan, Mithila Jugulam, and Maor Matzrafi, eds. Biology and Management of Weeds and Invasive Plant Species under Changing Climatic and Management Regimes. Frontiers Media SA, 2021. http://dx.doi.org/10.3389/978-2-88971-310-3.
Частини книг з теми "3108 Plant biology":
1
Nielsen, Jens Kvist. "Crucifer-feeding Chrysomelidae: Mechanisms of host plant finding and acceptance." In Biology of Chrysomelidae, 25–40. Dordrecht: Springer Netherlands, 1988. http://dx.doi.org/10.1007/978-94-009-3105-3_2.
2
Begossi, Alpina, and Woodruff W. Benson. "Host plants and defense mechanisms in Oedionychina (Alticinae)." In Biology of Chrysomelidae, 57–71. Dordrecht: Springer Netherlands, 1988. http://dx.doi.org/10.1007/978-94-009-3105-3_4.