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1
Abrudan, Monica I., Fokko Smakman, Ard Jan Grimbergen, Sanne Westhoff, Eric L. Miller, Gilles P. van Wezel, and Daniel E. Rozen. "Socially mediated induction and suppression of antibiosis during bacterial coexistence." Proceedings of the National Academy of Sciences 112, no. 35 (July 27, 2015): 11054–59. http://dx.doi.org/10.1073/pnas.1504076112.
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Despite their importance for humans, there is little consensus on the function of antibiotics in nature for the bacteria that produce them. Classical explanations suggest that bacteria use antibiotics as weapons to kill or inhibit competitors, whereas a recent alternative hypothesis states that antibiotics are signals that coordinate cooperative social interactions between coexisting bacteria. Here we distinguish these hypotheses in the prolific antibiotic-producing genus Streptomyces and provide strong evidence that antibiotics are weapons whose expression is significantly influenced by social and competitive interactions between competing strains. We show that cells induce facultative responses to cues produced by competitors by (i) increasing their own antibiotic production, thereby decreasing costs associated with constitutive synthesis of these expensive products, and (ii) by suppressing antibiotic production in competitors, thereby reducing direct threats to themselves. These results thus show that although antibiotic production is profoundly social, it is emphatically not cooperative. Using computer simulations, we next show that these facultative strategies can facilitate the maintenance of biodiversity in a community context by converting lethal interactions between neighboring colonies to neutral interactions where neither strain excludes the other. Thus, just as bacteriocins can lead to increased diversity via rock–paper–scissors dynamics, so too can antibiotics via elicitation and suppression. Our results reveal that social interactions are crucial for understanding antibiosis and bacterial community dynamics, and highlight the potential of interbacterial interactions for novel drug discovery by eliciting pathways that mediate interference competition.
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Raatikainen, Olavi, Jouko Tuomisto, Risto Tahvonen, and Heikki Rosenqvist. "Polyene production of antagonistic Streptomyces species isolated from Sphagnum peat." Agricultural and Food Science 2, no. 6 (December 1, 1993): 551–60. http://dx.doi.org/10.23986/afsci.72671.
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Several isolates of Streptomyces species, suppressive against fungal growth and obtained from light-coloured Sphagnum peat, produced polyene antibiotics. The mechanism of growth suppression by these isolates is probably partially explained by antibiosis, since there was a significant difference in the antibiotic production by suppressive vs. non-suppressive isolates. The antibiotic consists of several individual components, which form an aromatic heptaene complex of the candicidin type containing p-aminoacetophenone and mycosamine moieties. The minimum inhibitory concentration (MIC) of the antibiotic against yeasts and fungi was the same as that of candicidin.
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Singh, Pawan, Navneet Verma, Prevesh Kumar, and Priynaka Nagu. "REVIEW ON A POTENTIAL OF ANTIBIOTICS." Journal of Drug Delivery and Therapeutics 8, no. 5-s (October 15, 2018): 35–40. http://dx.doi.org/10.22270/jddt.v8i5-s.1936.
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Observations about the growth of some microorganisms inhibiting the growth of other microorganisms have been reported since the late 1800s. These observations of antibiosis between microorganisms led to the discovery of natural antibacterial. This paper deliberates important findings of the educations conducted by numerous national and international combined organizations on a brief indication of the antibacterial agents׳ detection in recent years. In India especially the developing antibiotics, need to institute methods for the suitable choice of drug conduct a compound problem involving prescribers, dispensers, and consumers.
Keywords: Antibiotic, Antibiotic resistance, bacterial Infection
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Yang, Ping. "The Antibiosis of Trichoderma asperellum Resistance Plant Pathogenic Fungi." Advanced Materials Research 1073-1076 (December 2014): 1067–70. http://dx.doi.org/10.4028/www.scientific.net/amr.1073-1076.1067.
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T. asperellumhas been turned out was an important biocontrol fungus and can antagonize many plant pathogenic fungi through a variety of biocontrol mechanisms. The antibiosis was considered one of important mechanisms. The antibiosis ofT.asperellumresistance plant pathogenic fungi was examined in this paper. The antibiotic biosynthetic gene polyketide synthase genepksT1can be induced by pathogens. Moreover, the growth of the plant pathogens was inhibited byT. asperellumsecondary metabolites. The yield of antibiotic 6-PP was 1.32 mg 6-PP/g mycelial dry weight.T. asperellumcontrol plant pathogens through producing antifungal metabolites.
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Pusey, P. L., V. O. Stockwell, C. L. Reardon, T. H. M. Smits, and B. Duffy. "Antibiosis Activity of Pantoea agglomerans Biocontrol Strain E325 Against Erwinia amylovora on Apple Flower Stigmas." Phytopathology® 101, no. 10 (October 2011): 1234–41. http://dx.doi.org/10.1094/phyto-09-10-0253.
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Pantoea agglomerans E325, the active ingredient in a commercial product for fire blight control, was previously shown in vitro to produce a unique alkaline- and phosphate-sensitive antibiotic specific to Erwinia amylovora. Antibiosis was evaluated as a mode of antagonism on flower stigmas using two antibiosis-deficient mutants. On King's medium B, mutants E325ad1 and E325ad2 have stable smooth-butyrous or hypermucoid colony morphologies, respectively, and the parental strain E325 exhibits phenotypic plasticity with predominantly hypermucoid colonies accompanied by slower-growing, smooth-butyrous colonies. Mutants were tested against E. amylovora on stigmas of detached flowers of crab apple (Malus mandshurica) in growth chambers and apple (Malus domestica) in the orchard. Epiphytic fitness of the antibiosis-negative mutants was similar or greater than the parental strain as determined by relative area under the population curve (RAUPC). In laboratory and orchard trials, both mutants had significantly lower inhibitory activity against the pathogen (i.e., less reduction of E. amylovora RAUPC) compared with the parental strain. E325 and the mutants caused similar decreases in pH in a broth medium, indicating that acidification, which was previously reported as a possible mechanism of pathogen inhibition on stigmas, is not directly related to antibiosis. In this study we provide the first evidence for E325 antibiosis involved in E. amylovora growth suppression on apple flower stigmas.
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BROU, Kouassi Guy, Moroh Jean Luc ABOYA, Boni N’ZUE, Sékou DIABATÉ, Goli Pierre ZOUHOURI, Janat Ackanovna MAMYRBEKOVA-BEKRO, Koffi II Nazaire KOUASSI, Denezon Odette DOGBO, and Yves-Alain BEKRO. "Effect of glyphosate on antibiosis in the coevolution of the pathosystem Manihot esculenta-Colletotrichum gloeosporioides." Journal of Animal & Plant Sciences 48, no. 2 (May 31, 2021): 8637–48. http://dx.doi.org/10.35759/janmplsci.v48-2.
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The high use of glyphosate for weed and pest control of cassava crops in Africa, particularly in Côte d'Ivoire, is correlated with the increasing extent of cassava anthracnose in the cassava producing regions. This health situation raises the question of the existence of a combined effect of glyphosate and anthracnose infection on the defence response of the cassava plant. The study was on the effect of glyphosate on antibiosis in M. esculenta in the pathosystem with C. gloeosporioides. To achieve this objective, a classical fully randomized 3-repeat device was used and antibiosis was the factor studied with 3 modalities. Treatments carried out on the plots, 4 months after planting, were inoculation of test plots of cassava with C. gloeosporoides before they were treated with 4JAI glyphosate. The assessment of phenolic and flavonoid antibiosis levels was carried out on leaf and stem organs harvested from 1JHA to 45 JHA and from the day of glyphosate treatment to 41 JHA. Comparative flavonoid antibiosis profiles were determined by CCM at the stages of maximum inhibition and maximum accumulation. Results showed that the phenolic and flavonoid antibiosis content of plants in glyphosate-treated plots decreased progressively in all varieties studied from JATr 1 to JATr 7. After the seventh day, the respective amounts of phenolic and flavonoid antibiosis gradually increased from the 8th JATr to the 180th JATr. This study showed a negative but partial interference of glyphosate in the defense mechanism of cassava cultivars (Manihot esculenta). Brou et al., 2021 Journal of Animal & Plant Sciences (J.Anim.Plant Sci. ISSN 2071-7024) Vol.48 (2): 8637-8648 https://doi.org/10.35759/JAnmPlSci.v48-2.1 8638 RESUME L’importante utilisation du glyphosate pour le désherbage et la lutte contre les adventices des cultures de manioc en Afrique et notamment en Côte d’Ivoire, et l’étendue croissante des cas d’anthracnose du manioc dans les régions de production de cette culture, soulève la question d’un possible effet conjugué du glyphosate et de l’infection à l’anthracnose. Les auteurs ont étudié l’effet du glyphosate sur les antibioses chez M. esculenta dans le pathosystème avec C. gloeosporioides. Pour atteindre cet objectif, un dispositif classique à trois répétions complètement randomisées a été utilisé et les antibioses sont le facteur étudié avec 3 modalités. Les traitements réalisés sur les parcelles, 4 mois après plant plantation, ont été l’inoculation des parcelles tests de manioc par C. gloeosporoides avant que celles-ci ne soient traitées par le glyphosate 4JAI. L’évaluation des teneurs en antibioses phénoliques et flavonoïdiques a été réalisée sur les organes feuilles et tiges récoltées de 1JAI à 45 JAI et du jour du traitement au glyphosate à 41 JAT. Les profils comparatifs en antibioses flavonoïdiques ont été déterminés par CCM aux stades de l’inhibition maximale et de l’accumulation maximale. Les résultats ont montré que la teneur en antibioses phénoliques et flavonoïdiques des plantes des parcelles traitées avec le glyphosate ont diminué progressivement chez toutes les variétés étudiées du 1er JATr au 7ème JATr. Après le septième jour, les quantités respectives des antibioses phénoliques et de flavonoïdes ont augmenté progressivement du 8ème JATr au 180ème JATr. Il ressort de cette étude, une interférence négative mais partielle du glyphosate dans le mécanisme de défense des cultivars de manioc (Manihot esculenta).
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BROU, Kouassi Guy, Moroh Jean Luc ABOYA, Boni N’ZUE, Sékou DIABATÉ, Goli Pierre ZOUHOURI, Janat Ackanovna MAMYRBEKOVA-BEKRO, Koffi II Nazaire KOUASSI, Denezon Odette DOGBO, and Yves-Alain BEKRO. "Effect of glyphosate on antibiosis in the coevolution of the pathosystem Manihot esculenta-Colletotrichum gloeosporioides." Journal of Animal & Plant Sciences 48, no. 2 (May 31, 2021): 8637–48. http://dx.doi.org/10.35759/janmplsci.v48-2.1.
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The high use of glyphosate for weed and pest control of cassava crops in Africa, particularly in Côte d'Ivoire, is correlated with the increasing extent of cassava anthracnose in the cassava producing regions. This health situation raises the question of the existence of a combined effect of glyphosate and anthracnose infection on the defence response of the cassava plant. The study was on the effect of glyphosate on antibiosis in M. esculenta in the pathosystem with C. gloeosporioides. To achieve this objective, a classical fully randomized 3-repeat device was used and antibiosis was the factor studied with 3 modalities. Treatments carried out on the plots, 4 months after planting, were inoculation of test plots of cassava with C. gloeosporoides before they were treated with 4JAI glyphosate. The assessment of phenolic and flavonoid antibiosis levels was carried out on leaf and stem organs harvested from 1JHA to 45 JHA and from the day of glyphosate treatment to 41 JHA. Comparative flavonoid antibiosis profiles were determined by CCM at the stages of maximum inhibition and maximum accumulation. Results showed that the phenolic and flavonoid antibiosis content of plants in glyphosate-treated plots decreased progressively in all varieties studied from JATr 1 to JATr 7. After the seventh day, the respective amounts of phenolic and flavonoid antibiosis gradually increased from the 8th JATr to the 180th JATr. This study showed a negative but partial interference of glyphosate in the defense mechanism of cassava cultivars (Manihot esculenta). Brou et al., 2021 Journal of Animal & Plant Sciences (J.Anim.Plant Sci. ISSN 2071-7024) Vol.48 (2): 8637-8648 https://doi.org/10.35759/JAnmPlSci.v48-2.1 8638 RESUME L’importante utilisation du glyphosate pour le désherbage et la lutte contre les adventices des cultures de manioc en Afrique et notamment en Côte d’Ivoire, et l’étendue croissante des cas d’anthracnose du manioc dans les régions de production de cette culture, soulève la question d’un possible effet conjugué du glyphosate et de l’infection à l’anthracnose. Les auteurs ont étudié l’effet du glyphosate sur les antibioses chez M. esculenta dans le pathosystème avec C. gloeosporioides. Pour atteindre cet objectif, un dispositif classique à trois répétions complètement randomisées a été utilisé et les antibioses sont le facteur étudié avec 3 modalités. Les traitements réalisés sur les parcelles, 4 mois après plant plantation, ont été l’inoculation des parcelles tests de manioc par C. gloeosporoides avant que celles-ci ne soient traitées par le glyphosate 4JAI. L’évaluation des teneurs en antibioses phénoliques et flavonoïdiques a été réalisée sur les organes feuilles et tiges récoltées de 1JAI à 45 JAI et du jour du traitement au glyphosate à 41 JAT. Les profils comparatifs en antibioses flavonoïdiques ont été déterminés par CCM aux stades de l’inhibition maximale et de l’accumulation maximale. Les résultats ont montré que la teneur en antibioses phénoliques et flavonoïdiques des plantes des parcelles traitées avec le glyphosate ont diminué progressivement chez toutes les variétés étudiées du 1er JATr au 7ème JATr. Après le septième jour, les quantités respectives des antibioses phénoliques et de flavonoïdes ont augmenté progressivement du 8ème JATr au 180ème JATr. Il ressort de cette étude, une interférence négative mais partielle du glyphosate dans le mécanisme de défense des cultivars de manioc (Manihot esculenta).
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KONG, KOK-FAI, LISA SCHNEPER, and KALAI MATHEE. "Beta-lactam antibiotics: from antibiosis to resistance and bacteriology." APMIS 118, no. 1 (January 2010): 1–36. http://dx.doi.org/10.1111/j.1600-0463.2009.02563.x.
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Frankel, DavidH. "Cow-lick antibiosis." Lancet 345, no. 8953 (April 1995): 850. http://dx.doi.org/10.1016/s0140-6736(95)92980-0.
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Pusey, P. L., V. O. Stockwell, and D. R. Rudell. "Antibiosis and Acidification by Pantoea agglomerans Strain E325 May Contribute to Suppression of Erwinia amylovora." Phytopathology® 98, no. 10 (October 2008): 1136–43. http://dx.doi.org/10.1094/phyto-98-10-1136.
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Pantoea agglomerans strain E325, a commercially available antagonist for fire blight of apple and pear, was originally selected through screening based on suppression of Erwinia amylovora on flower stigmas, but specific mechanisms of antagonism were unknown. Bacterial modification of pH was evaluated as a possible mechanism by analyzing stigma exudates extracted from ‘Gala’ apple stigmas. The pH values for field samples were only slightly lower than controls, but indicated a range (pH 5 to 6) conducive for antibiotic activity according to subsequent assays. Under low-phosphate and low-pH conditions, an antibacterial product of E325 with high specificity to E. amylovora was effective at low concentrations. A minimum of 20 to 40 ng of a ninhydrin-reactive compound purified using RP-HPLC caused visible inhibition in assays. Activity was heat stable and unaffected by amino acids, iron, or enzymes known to affect antibiotics of P. agglomerans. Antibiosis was diminished, however, under basic conditions, and with increasing phosphate concentrations at pH 6 and 7. Inhibition was not observed in media containing phosphate concentrations commonly used in antibiosis assays. We propose that E325 suppresses the fire blight pathogen not only by competing for nutrients on the stigma, but by producing an antibiotic specific to E. amylovora. Further work is necessary to substantiate that the compound is produced and active on flower stigmas.
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Muriuki, Susan W., Johnstone O. Neondo, and Nancy L. M. Budambula. "Detection and Profiling of Antibiotic Resistance among Culturable Bacterial Isolates in Vended Food and Soil Samples." International Journal of Microbiology 2020 (September 7, 2020): 1–12. http://dx.doi.org/10.1155/2020/6572693.
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The emergence and persistence of antibiotic resistance remain formidable health challenges. This study aimed at detecting and profiling antibiotic resistance of bacterial contaminants in vended food and the environment. Seventy antibiotic-resistant bacterial isolates were isolated from fried fish, African sausages, roasted meat, smokies, samosa, chips (potato fries), vegetable salads, and soil samples collected from Embu Town and Kangaru Market in Embu County, Kenya. The antibiotic susceptibility test, morphological and biochemical characterization, antibiosis assay, polymerase chain reaction-based detection of antibiotic resistance genes, and sequencing of the 16S rRNA gene were done. Analysis of variance on all measured data was done, and Tukey’s honest test was used to compare and separate mean diameters of zones inhibition. Resistance of bacterial isolates to antibiotics was chloramphenicol (90%), cefotaxime (84.29%), nalidixic acid (81.43%), tetracycline (77.14%), amoxicillin (72.86%), gentamycin (48.57%), streptomycin (32.86%), and trimethoprim + sulphamethoxazole (30%). Isolate KMP337, Salmonella spp., exhibited highly significant antibiosis against S. aureus recording a mean inhibition diameter and standard error (SE) of 16.33 ± 0.88 mm, respectively, at P=0.001. The 70 bacterial isolates belonged to Bacillus, Paraclostridium, Lysinibacillus, Virgibacillus, and Serratia genera. The study isolated Bacillus wiedmannii (KC75) which is a risk group 2 as well as Serratia marcescens (KMP95) and Bacillus anthracis (KS606) which are risk group 3 organisms. The presence of antibiotic resistance genes Tet A, BlaTEM, StrB, Dfr A, Amp, and FloR genes was confirmed by a polymerase chain reaction. Samples from Kangaru Market recorded a higher (88.57%) proportion of resistant isolates as compared to isolates from Embu Town (11.43%). The study confirmed the presence of antibiotic-resistant bacteria in vended fast food and the soil in Embu Town and Kangaru Market. This study calls for continuous monitoring of bacterial status and hygienic handling of vended food.
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Butrón, A., B. Ordás, P. Revilla, G. Sandoya, A. Ordás, and R. A. Malvar. "Is leaf or sheath antibiosis involved in the resistance of maize composite EPS12 to Sesamia nonagrioides?" Canadian Entomologist 137, no. 3 (June 2005): 350–55. http://dx.doi.org/10.4039/n04-049.
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AbstractThe pink stem borer (PSB) (Sesamia nonagrioides Lefèbvre, 1827; Lepidoptera: Noctuidae) is the main insect pest of maize (Zea mays L., Poaceae) in the Mediterranean area. Maize varieties partially resistant to PSB have been identified, but few studies have documented the mechanisms of resistance involved. The objectives of this research were to study the levels of leaf and sheath antibiosis of a maize population, EPS12, and determine whether antibiosis improved over the selection process for less stalk tunneling. A hybrid check and two Bacillus thuringiensis (Bt) hybrids were also examined. Several bioassays were carried out in a control chamber to evaluate antibiosis of maize leaves and sheaths against PSB larvae. Leaf antibiosis was significantly higher for EPS12 than for the hybrid check and sheath antibiosis was low for all non-Bt hybrids studied. We conclude that leaf and sheath antibiosis was not significantly improved during the selection process. Future efforts should look for other possible mechanisms of resistance, such as stem rind antibiosis.
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Hasanuddin, Hasanuddin. "UJI AKTIVITAS ANTIBIOSIS PSEUDOMONADS PENDARFLUOR TERHADAP Rigidoporus lignosus (Klotszch) Imazeki PENYEBAB PENYAKIT AKAR PUTIH." Jurnal Hama dan Penyakit Tumbuhan Tropika 11, no. 1 (February 10, 2011): 87–94. http://dx.doi.org/10.23960/j.hptt.11187-94.
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The potential of fluorescent bacteria as biological control agents for white root disease caused by Rigidoporus lignosus has been investigated. Isolation of bacteria from the soil using S1 media produced two fluorescent bacteria isolates. Using the Microbact 12A+12B method, both bacteria were identified as Pseudomonas fluorescens and P. aeruginosa. These two species of bacteria were then used as antibiosis activity test against R. lignosus. Four series antibiosis activity tests were done, that were antibiosis test of media culture bacteria growth to R. lignosus colony, antibiosis test of dry fluorescent pigment extract to R. lignosus, influence of Fe3+ to antibiosis activity of bacteria test, and affinity of media supernatant to Fe3+. The results were: antibiosis activity of King’s B (KB) media was more effective than media 523 in the inhibition of R. lignosus colony growth. There was no significant different antibiosis activity of dry fluorescent pigment extract from media KB and media 523 in the inhibition of R. lignosus colony growth. The level of Fe3+ in the media might influence antibiosis activity of fluorescent pigment. Affinity test of KB supernatant from fluorescent bacteria culture with Fe3+ showed an absorption peak of 410 nm on spectrophotometer, and none for the fungi. These results indicate that P. fluorescens and P. aeruginosa produce cathecol-type siderophore with high affinity against Fe3+ compared with hydroxamate-type siderophore which is generally produced by fungus.
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Wackett, Lawrence P. "Antibiosis in the environment." Environmental Microbiology Reports 6, no. 5 (October 2014): 532–33. http://dx.doi.org/10.1111/1758-2229.12213.
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Arlt, Alexander, Wiebke Erhart, Clemens Schafmayer, Hanns-Christoph Held, and Jochen Hampe. "Antibiosis of Necrotizing Pancreatitis." Viszeralmedizin 30, no. 5 (2014): 2. http://dx.doi.org/10.1159/000367948.
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McColl, AL, and RM Noble. "Evaluation of a rapid mass-screening technique for measuring antibiosis to Helicoverpa spp. in cotton cultivars." Australian Journal of Experimental Agriculture 32, no. 8 (1992): 1127. http://dx.doi.org/10.1071/ea9921127.
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A study of a variety of screening techniques was undertaken to determine their suitability for an antibiosis-enhancing cotton-breeding program. Techniques trialled included 9 different larval bioassays of varying durations on squares, leaves, and seedlings of cotton-using larvae of different ages. Chemical analyses of squares and seedlings, and a field trial to validate laboratory findings, were also conducted. The 'standard' measure of antibiosis in cotton plants, using long-term (8-day) bioassays based on larval weight gain, was found to be unsuitable for mass screening cotton plants for antibiosis to the cotton bollworm, Helicoverpa armigera (Hnbner), in Central Queensland. A 48-h technique using instar VI larvae proved as dependable as the standard, but faster and more energy-efficient, making it more suitable for mass screening. Chemical analyses supported previous findings that terpenoid aldehydes (i.e. gossypol) in cotton produce important antibiotic activity against H. armigera. Highly significant negative correlations were shown between gossypol content of ingested plant material and larval weight gains. In contrast, there was no relationship between condensed tannin content and larval weight gain. The relationships between larval bioassays and allelochemical content of cultivars were confirmed in a field trial.
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Sturz, A. V., R. D. Peters, M. R. Carter, J. B. Sanderson, B. G. Matheson, and B. R. Christie. "Variation in antibiosis ability, against potato pathogens, of bacterial communities recovered from the endo- and exoroots of potato crops produced under conventional versus minimum tillage systems." Canadian Journal of Microbiology 51, no. 8 (August 1, 2005): 643–54. http://dx.doi.org/10.1139/w05-041.
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The culturable component of bacterial communities found in the endoroot and associated exoroot (root zone soil) was examined in potatoes (Solanum tuberosum L.) grown under either conventional or minimum tillage systems. Bacterial species – abundance relationships were determined and in vitro antibiosis ability investigated to discover whether tillage practice or bacteria source (endo- or exoroot) influenced bacterial community structure and functional versatility. Antibiosis abilities against Phytophthora erythroseptica Pethyb. (causal agent of pink rot of potatoes), Streptomyces scabies (Thaxt.) Waksm. and Henrici) (causal agent of potato common scab), and Fusarium oxysporum Schlecht. Emend. Snyder and Hansen (causal agent of fusarium potato wilt) were selected as indicators of functional versatility. Bacterial community species richness and diversity indices were significantly greater (P = 0.001) in the exoroot than in the endoroot. While both endo- and exoroot communities possessed antibiosis ability against the phytopathogens tested, a significantly greater proportion (P = 0.0001) of the endoroot population demonstrated antibiosis ability than its exoroot counterpart against P. erythroseptica and F. oxysporum. Tillage regime had no significant influence on species-abundance relationships in the endo- or exoroot but did influence the relative antibiosis ability of bacteria in in vitro challenges against S. scabies, where bacteria sourced from minimum tillage systems were more likely to have antibiosis ability (P = 0.0151). We postulate that the difference in the frequency of isolates with antibiosis ability among endoroot versus exoroot populations points to the adaptation of endophytic bacterial communities that favour plant host defence against pathogens that attack the host systemically.Key words: antibiosis, bacterial endophytes, Fusarium oxysporum, Phytophthora erythroseptica, Streptomyces scabies, potatoes.
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Prihatiningsih, Nur, Triwidodo Arwiyanto, Bambang Hadisutrisno, and Jaka Widada. "MEKANISME ANTIBIOSIS BACILLUS SUBTILIS B315 UNTUK PENGENDALIAN PENYAKIT LAYU BAKTERI KENTANG." JURNAL HAMA DAN PENYAKIT TUMBUHAN TROPIKA 15, no. 1 (March 2, 2015): 64. http://dx.doi.org/10.23960/j.hptt.11564-71.
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Antibiosis mechanism of Bacillus subtilis B315 for controlling potato bacterial wilt disease. Bacillus subtilis B315 isolated from rhizospheric potato has antibiosis mechanism against Ralstonia solanacearum in vitro and become potentially used as controlling method of bacterial wilt in the field. The objectives of this research were to study the mechanism of B.subtilis B315 in controlling bacterial wilt disease, to study of B. subtilis B315 potency as both biocontrol and plant growth promoter, and to evaluate the mechanism as biocontrol agent. This green house experiment used CRD (Completely Randomized Design) with 5 treatments and 6 replicates. The treatments were control (without B. subtilis B315), B. subtilis B315 wild type, antibiosis mutant M16, antibiosis mutant M4, and antibiosis mutant M14. Variables observed were incubation period, disease index, infection rate, effectiveness of control, and growth components (i.e number of bud, plant height, leaf area, plant fresh and dry weight). The result of this research showed that B. subtilis B315 could delay incubation period, suppressed the disease index up to 64,9% and could promote the plant growth (leaf area). B. subtilis B315 had the antibiosis and other mechanisms that induced sistemic resistance. The implication of this research was that B. subtilis B315 could be used for biocontrol the bacterial wilt and promoted the potato growth.
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Palaniswamy, P., R. J. Lamb, and R. P. Bodnaryk. "ANTIBIOSIS OF PREFERRED AND NON-PREFERRED HOST-PLANTS FOR THE FLEA BEETLE, PHYLLOTRETA CRUCIFERAE (GOEZE) (COLEOPTERA: CHRYSOMELIDAE)." Canadian Entomologist 129, no. 1 (February 1997): 43–49. http://dx.doi.org/10.4039/ent12943-1.
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AbstractThe antibiosis of crucifers to flea beetles, Phyllotreta cruciferae (Goeze), was compared for Brassica juncea L., B. napus L., and B. rapa L. with low antixenosis, B. carinata L. and Sinapis alba L. with moderate antixenosis, and Thlaspi arvense L. with high antixenosis. Adult flea beetles collected from the field in early spring fed actively on intact or excised leaves of all plants except T. arvense. The beetles survived, and gained weight and fat on the Brassica species and S. alba, but not on intact foliage of T. arvense. No antibiosis was detected in any of the Brassica species or in S. alba. Intact foliage of T. arvense was so antixenotic that beetles probably starved rather than suffered from antibiosis. A low level of antibiosis was detected in excised foliage of T. arvense where the antixenosis was lost. These experiments show that estimates of beetle survival, dry weight, and fat content can be used in the laboratory to test small numbers of candidate plants for antibiosis. However, the level of antibiosis appears to vary less among Brassica species and related plants than does the level of antixenosis, and so the latter is a more promising type of resistance for use against flea beetles in canola.
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Yao, Luming, Biyun Yang, Xiaohong Ma, Shuangshuang Wang, Zhe Guan, Biao Wang, and Yina Jiang. "A Genome-Wide View of Transcriptional Responses during Aphis glycines Infestation in Soybean." International Journal of Molecular Sciences 21, no. 15 (July 22, 2020): 5191. http://dx.doi.org/10.3390/ijms21155191.
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Soybean aphid (Aphis glycines Matsumura) is one of the major limiting factors in soybean production. The mechanism of aphid resistance in soybean remains enigmatic as little information is available about the different mechanisms of antibiosis and antixenosis. Here, we used genome-wide gene expression profiling of aphid susceptible, antibiotic, and antixenotic genotypes to investigate the underlying aphid–plant interaction mechanisms. The high expression correlation between infested and non-infested genotypes indicated that the response to aphid was controlled by a small subset of genes. Plant response to aphid infestation was faster in antibiotic genotype and the interaction in antixenotic genotype was moderation. The expression patterns of transcription factor genes in susceptible and antixenotic genotypes clustered together and were distant from those of antibiotic genotypes. Among them APETALA 2/ethylene response factors (AP2/ERF), v-myb avian myeloblastosis viral oncogene homolog (MYB), and the transcription factor contained conserved WRKYGQK domain (WRKY) were proposed to play dominant roles. The jasmonic acid-responsive pathway was dominant in aphid–soybean interaction, and salicylic acid pathway played an important role in antibiotic genotype. Callose deposition was more rapid and efficient in antibiotic genotype, while reactive oxygen species were not involved in the response to aphid attack in resistant genotypes. Our study helps to uncover important genes associated with aphid-attack response in soybean genotypes expressing antibiosis and antixenosis.
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van den Berg, J., and M. C. van der Westhuizen. "Chilo partellus (Lepidoptera: Pyralidae) moth and larval response to levels of antixenosis and antibiosis in sorghum inbred lines under laboratory conditions." Bulletin of Entomological Research 87, no. 5 (October 1997): 541–45. http://dx.doi.org/10.1017/s0007485300041419.
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AbstractTwo experiments were conducted to determine Chilo partellus (Swinhoe) moth and larval response on sorghum lines differing in levels of antibiosis and antixenosis. The inbred lines were E 302, IS 2205, IS 2122 and SA 2681, all reportedly varying in levels of antibiosis and ovipositional and larval antixenosis to C. partellus. Ovipositional antixenosis was evaluated in choice tests under cage conditions and significant differences were observed in the average number of egg batches per line. E 302 received the greatest number of egg batches. Antibiosis and larval antixenosis was evaluated with artificial infestation in a greenhouse. Significant differences occurred in larval numbers and mean larval mass on different lines, with E 302 possessing the greatest level of antibiosis resistance. This study indicates that resistant genotypes such as E 302 may exhibit high levels of antibiosis or larval antixenosis, but may also be preferred for oviposition. The size of egg batches was not influenced by ovipositional antixenosis. The potential effect of ovipositional antixenosis mechanisms on pest populations under field conditions is discussed.
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Heungens, K., and J. L. Parke. "Postinfection Biological Control of Oomycete Pathogens of Pea by Burkholderia cepacia AMMDR1." Phytopathology® 91, no. 4 (April 2001): 383–91. http://dx.doi.org/10.1094/phyto.2001.91.4.383.
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Burkholderia cepacia AMMDR1 is a biocontrol agent that reduces Pythium damping-off and Aphanomyces root rot severity on peas in the field. We studied the effect of B. cepacia AMMDR1 on post-infection stages in the life cycles of these pathogens, including mycelial colonization of the host, production of oogonia, and production of secondary zoospore inoculum. We used Burkholderia cepacia 1324, a seed and rootcolonizing but antibiosis-deficient Tn5 mutant of B. cepacia AMMDR1, to study mechanisms of biological control other than antibiosis. B. cepacia AMMDR1 significantly reduced Pythium aphanidermatum postinfection colonization and damping-off of pea seeds, even when the bacteria were applied 12 h after zoospore inoculation. B. cepacia AMMDR1 also significantly reduced colonization of taproots by Aphanomyces euteiches mycelium, but only when the bacteria were applied at high population densities at the site of zoospore inoculation. The antibiosisdeficient mutant, B. cepacia 1324, had no effect on mycelial colonization of seeds or roots by Pythium aphanidermatum nor A. euteiches, suggesting that antibiosis is the primary mechanism of biological control. B. cepacia AMMDR1, but not B. cepacia 1324, reduced production of A. euteiches oogonia. This effect occurred even when the population size of B. cepacia AMMDR1 was too small to cause a reduction in lesion length early on in the infection process and may result from in situ antibiotic production. B. cepacia AMMDR1 had no effect on the production of secondary zoospores of A. euteiches from infected roots. The main effects of B. cepacia AMMDR1 on postinfection stages in the life cycles of these pathogens therefore were reductions in mycelial colonization by Pythium aphanidermatum and in formation of oogonia by A. euteiches. No mechanism other than antibiosis could be identified.
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Hastings, J. W., and M. E. Stiles. "Antibiosis ofLeuconostoc gelidumisolated from meat." Journal of Applied Bacteriology 70, no. 2 (February 1991): 127–34. http://dx.doi.org/10.1111/j.1365-2672.1991.tb04438.x.
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Tennant, Bryn. "Antimicrobial drug resistance and antibiosis." Companion Animal 21, no. 11 (November 2, 2016): 626–33. http://dx.doi.org/10.12968/coan.2016.21.11.626.
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Tennant, Bryn. "Antimicrobial drug resistance and antibiosis." Veterinary Nurse 7, no. 10 (December 2, 2016): 576–81. http://dx.doi.org/10.12968/vetn.2016.7.10.576.
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Cruzado Razco, Lizardo, Daisy Paola Gutierrez Calderon, and Segundo Guillermo Ruiz Reyes. "Ensayo químico y efecto de antibiosis in vitro de la miel de abeja sobre microorganismos grampositivos y gramnegativos." REVISTA MÉDICA VALLEJIANA/ Vallejian Medical Journal 4, no. 2 (December 9, 2019): 95–108. http://dx.doi.org/10.18050/revistamedicavallejiana.v4i2.2233.
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El presente trabajo está orientado a determinar los componentes químicos y el efecto de antibiosis “in vitro” de la miel de abeja, frente a bacterias grampositivas y gramnegativas, comúnmente causantes de enfermedades prevalentes en la población. En el ensayo químico se determinaron metabolitos primarios y secundarios; mediante reacciones químicas correspondientes presentando flavonoides, esteroides y leucoantocianidinas. Para el efecto de antibiosis “in vitro” se empleó el Método de Difusión en Discos– Método de Kirby&Bauer. Los resultados de antibiosis fueron positivos para Escherichia coli, Salmonella enteritidis, Staphylococcus aureus y negativo para Klebsiella pneumoniae.
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Brou, Kouassi Guy, Jean Luc Aboya Moroh, Sékou Diabaté, Boni N’zue, Goli Pierre Zouhouri, Janat Ackanovna Mamyrbekova-Bekro, II Nazaire Koffi Kouassi, Denézon Odette Dogbo, and Yves-Alain Bekro. "Physiological mechanism of resistance antibiosis to anthracnose of different Manihot varieties." International Journal of Biological and Chemical Sciences 14, no. 8 (December 9, 2020): 2854–69. http://dx.doi.org/10.4314/ijbcs.v14i8.16.
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Cassava is one of the main food crops in Africa, particularly in Côte d'Ivoire. However, the cultivated varieties are prone to attack by diseases. The present work focused on the role of phenolic and in particular flavonoid resistance markers in the Manihot esculenta-Colletotrichum gloeosporioides pathosystem. The aim was to elucidate the involvement of flavonoid antibiosis in the natural defense of three cultivars of M. esculenta when confronted with attacks by C. gloeosporioides. The quantitative dosage approach for total phenolics and flavonoids as well as the identification of flavonoid antibiosis have been carried out. The results revealed that the cultivars 9620A, TMS30572 and YACE of M. esculenta have, after the C. gloeosporioides inoculation tests, reacted early 2 days after inoculation (JAI) and accumulated relatively high levels of antibiosis phenolic and flavonoid 9JAI. The three cultivars accumulated constitutive flavonoid antibiosis and 3 neosynthesized antibiosis from 7JAI to 9JAI. The accumulation of flavonoid antibacterials neosynthesized in the stems and in the leaves testify to the expression of a systemic resistance of the cassava plants. The cultivars 9620A and TMS30572 are more tolerant than cultivar YACE. This study approach has made it possible to discriminate between cultivars and can therefore be used as a complementary selection tool to traditional selection tests.Keywords: Manihot esculenta, anthracnose, flavonoïd antibisis, glyphosate.
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le Roes, Marilize, and Paul R. Meyers. "Actinomadura rudentiformis sp. nov., isolated from soil." International Journal of Systematic and Evolutionary Microbiology 57, no. 1 (January 1, 2007): 45–50. http://dx.doi.org/10.1099/ijs.0.64438-0.
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As part of an antibiotic-screening programme, the actinomycete strain HMC1T was isolated from soil collected from the banks of the Gamka River in the Swartberg Nature Reserve, Western Cape Province, South Africa. The isolate produced branching vegetative mycelia, which entwined to form rope-like structures. It exhibited antibiosis against Enterococcus faecium VanA (a vancomycin-resistant clinical strain) and Mycobacterium aurum A+. Organic solvent extracts of the culture filtrate and mycelial mass of strain HMC1T exhibited moderate antibiosis against Mycobacterium aurum A+, Mycobacterium bovis BCG (Tokyo) and Mycobacterium tuberculosis H37RvT. The chemotaxonomic characteristics of strain HMC1T corresponded with those of members of the genus Actinomadura. Furthermore, phylogenetic analysis based on the 16S rRNA gene showed that the strain was closely related to members of the genus Actinomadura. Phenotypic and 16S rRNA gene sequence analyses indicated that strain HMC1T represents a novel species of the genus Actinomadura, for which the name Actinomadura rudentiformis sp. nov. is proposed. The type strain is HMC1T (=DSM 44962T=NRRL B-24458T).
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Sah, Shiv Nandan, and Binod Lekhak. "Screening of Antibiotic Producing Actinomycetes for Antibiosis from Soil of Siraha, Nepal." Himalayan Journal of Science and Technology 1 (December 1, 2017): 20–25. http://dx.doi.org/10.3126/hijost.v1i0.25817.
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The increasing need of novel antibiotics has provided a pace for the search of antibiotics from actinomycetes. Primary and secondary screenings of antibiotic producing actinomycetes from the soil of Siraha (75-600 m) were performed. The minimum inhibitory concentration of the metabolites was determined against E. coli. Macroscopic, microscopic and biochemical characterization were performed for the identification of presumptive genera. Characterization of the antibacterial substances was done by TLC. Among 92 isolates, 22 showed antibacterial activity against at least 1 bacterium out of 6 test bacteria used. Microscopy and other characteristics studies revealed that 19 (86.36%) were Streptomyces spp.,1 (4.55%) was Thermomonospora spp., and 2 (9.09 %) were unidentified. Five potent isolates were selected for the secondary screening where 2 isolates inhibited Gram negative bacteria with an MIC value of 1.2 mg/mL for each isolate. TLC showed that both antibiotics produced only one spot suggesting the presence of one active compound other than vancomycin (standard). The active isolates from primary screening were heterogeneous in their overall macroscopic, biochemical, and physiological characteristics. The two potent isolates showing antibacterial activity were found to belong to different distinct taxonomic groups.
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Limbu, Dhiren Subba, Ramesh Majhi, ShivNandan Sah, Kamana Bantawa, and Bishan Rai. "Screening of Antibiotic producing Actinomycetes for Antibiosis from soil of Sunsari, Nepal." Himalayan Journal of Science and Technology 7, no. 1 (December 31, 2023): 101–9. http://dx.doi.org/10.3126/hijost.v7i1.61136.
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Actinomycetes, slow-growing gram-positive bacteria, are useful in the search for bioactive compounds. A total of 24 different actinomycete strains were recovered from farming soil samples collected from the Sunsari district. The isolates were then tested against two gram-positive and three gram-negative bacteria. Results showed that 21% of all isolates are antibacterial at least, one of the test organisms, Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella Typhi, and Pseudomonas spp. According to antibacterial activity and spectrum broadness, one of the isolates (S11) was selected for secondary screening. The minimum inhibitory concentration (MIC) of crude antibacterial substances extracted from the broth culture of the isolate (S11) was found to be 1.3 mg/ml against test organisms. The chromatogram in TLC showed only one spot with an Rf value of 0.87 by the isolate suggesting that the isolate produced only one compound which was utterly different from the spot with an Rf value of 0.94 paid by gentamycin. According to identification by Microscopy (1000X) and overall biochemical, and physiological characteristics, the isolate was considered Streptomyces antibioticus, a distinct taxonomic group.
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Quecine, Maria Carolina, Teresa A. Kidarsa, Neal C. Goebel, Brenda T. Shaffer, Marcella D. Henkels, T. Mark Zabriskie, and Joyce E. Loper. "An Interspecies Signaling System Mediated by Fusaric Acid Has Parallel Effects on Antifungal Metabolite Production by Pseudomonas protegens Strain Pf-5 and Antibiosis of Fusarium spp." Applied and Environmental Microbiology 82, no. 5 (December 11, 2015): 1372–82. http://dx.doi.org/10.1128/aem.02574-15.
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ABSTRACTPseudomonas protegensstrain Pf-5 is a rhizosphere bacterium that suppresses soilborne plant diseases and produces at least seven different secondary metabolites with antifungal properties. We derived mutants of Pf-5 with single and multiple mutations in biosynthesis genes for seven antifungal metabolites: 2,4-diacetylphoroglucinol (DAPG), pyrrolnitrin, pyoluteorin, hydrogen cyanide, rhizoxin, orfamide A, and toxoflavin. These mutants were tested for inhibition of the pathogensFusarium verticillioidesandFusarium oxysporumf. sp.pisi. Rhizoxin, pyrrolnitrin, and DAPG were found to be primarily responsible for fungal antagonism by Pf-5. Previously, other workers showed that the mycotoxin fusaric acid, which is produced by manyFusariumspecies, includingF. verticillioides, inhibited the production of DAPG byPseudomonasspp. In this study, amendment of culture media with fusaric acid decreased DAPG production, increased pyoluteorin production, and had no consistent influence on pyrrolnitrin or orfamide A production by Pf-5. Fusaric acid also altered the transcription of biosynthetic genes, indicating that the mycotoxin influenced antibiotic production by Pf-5 at the transcriptional level. Addition of fusaric acid to the culture medium reduced antibiosis ofF. verticillioidesby Pf-5 and derivative strains that produce DAPG but had no effect on antibiosis by Pf-5 derivatives that suppressedF. verticillioidesdue to pyrrolnitrin or rhizoxin production. Our results demonstrated the importance of three compounds, rhizoxin, pyrrolnitrin, and DAPG, in suppression ofFusariumspp. by Pf-5 and confirmed that an interspecies signaling system mediated by fusaric acid had parallel effects on antifungal metabolite production and antibiosis by the bacterial biological control organism.
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Migui, S. M., and R. J. Lamb. "Patterns of resistance to three cereal aphids among wheats in the genus Triticum (Poaceae)." Bulletin of Entomological Research 93, no. 4 (July 2003): 323–33. http://dx.doi.org/10.1079/ber2003246.
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AbstractForty-one accessions of wild and cultivated wheats belonging to 19 Triticum species were tested in the field for resistance to three species of aphids, Rhopalosiphum padi Linnaeus, Sitobion avenae Fabricius and Schizaphis graminum Rondani. Antibiotic resistance was estimated by the increase in biomass of aphids over 21 days on adult plants. Overall resistance was estimated by the plant biomass lost due to aphid infestation. All three species of aphids survived and reproduced on all wheats, and reduced spike biomass compared to uninfested controls. The level of antibiosis varied among wheat species and among accessions, with accessions from three, five and one species showing antibiosis to R. padi, S. avenae and S. graminum, respectively. Overall resistance to the three aphid species was observed in five to seven accessions per aphid species. Resistance was usually specific to one aphid species. The frequency of accessions with antibiosis or overall resistance was associated with the ploidy level of the plant species. Except for overall resistance to R. padi, resistance was highest for diploid species and lowest for hexaploid species. No consistent relationship between resistance and level of domestication was detected. Accessions of the wild wheats, Triticum boeoticum Bois, Triticum tauschii (Coss.) Schmal. and Triticum araraticum Jakubz. exhibited high levels of resistance to aphids, as did Triticum monococcum L. which is derived from T. boeoticum. Nevertheless, individual susceptible or resistant accessions occurred at all levels within the evolutionary tree of wheat.
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Paudyal, Sulochana, John Scott Armstrong, Kristopher L. Giles, Mark E. Payton, George P. Opit, and Ankur Limaje. "Categories of Resistance to Sugarcane Aphid (Hemiptera: Aphididae) Among Sorghum Genotypes." Journal of Economic Entomology 112, no. 4 (April 11, 2019): 1932–40. http://dx.doi.org/10.1093/jee/toz077.
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Abstract The sugarcane aphid Melanaphis sacchari (Zehnter) (Hemiptera: Aphididae) has emerged as a potential threat to sorghum (Sorghum bicolor (L.) Moench) production in the United States. Since the late summer of 2013, finding and advancing M. sacchari-resistant germplasm has been a priority for all stakeholders involved. We evaluated 23 sorghum genotypes for resistance to the sugarcane aphid by testing for tolerance, and antixenosis. In addition, nine sorghum germplasm were evaluated for the expression of antibiosis. Free-choice and no-choice tests were conducted to explore the functional categories of resistance. Levels of resistance to M. sacchari were compared with the known resistant ‘TX 2783’ and the susceptible ‘KS 585’. Sorghum entries AG1201, AG1301, W844-E, and DKS 37-07 were identified as expressing tolerance, antibiosis, and antixenosis, while H13073 expressed antibiosis and GW1489 expressed both tolerance and antibiosis. These resistant sorghums identified during this study will have a significant impact on reducing economic damage from the sugarcane aphid infestations.
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Anderson, L. Meadow, Virginia O. Stockwell, and Joyce E. Loper. "An Extracellular Protease of Pseudomonas fluorescens Inactivates Antibiotics of Pantoea agglomerans." Phytopathology® 94, no. 11 (November 2004): 1228–34. http://dx.doi.org/10.1094/phyto.2004.94.11.1228.
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Pseudomonas fluorescens A506 and Pantoea agglomerans strains Eh252 and C9-1 are biological control agents that suppress fire blight, an important disease of pear and apple caused by the bacterium Erwinia amylovora. Pseudomonas fluorescens strain A506 suppresses disease largely through competitive exclusion of E. amylovora on surfaces of blossoms, the primary infection court, whereas Pantoea agglomerans strains Eh252 and C9-1 produce antibiotics that are toxic to E. amylovora. In this study, an extracellular protease produced by A506 is characterized and evaluated for its capacity to inactivate the antibiotics produced by the strains of Pantoea agglomerans. Activity of the extracellular protease was optimal at pH 9 and inhibited by zinc- or calcium-chelators, indicating that the protease is an alkaline metalloprotease. In an agar plate bioassay, partially purified extracellular protease inactivated the antibiotics mccEh252 and herbicolin O, which are produced by Pantoea agglomerans strains Eh252 and C9-1, respectively. Derivatives of A506 deficient in extracellular protease production were obtained by transposon mutagenesis, and the aprX gene encoding the protease was cloned and sequenced. Strain A506 inactivated mccEh252 and herbicolin O in agar plate bioassays, whereas the aprX mutant did not inactivate the antibiotics. Both A506 and the aprX mutant were insensitive to antibiosis by C9-1 and Eh252; thus, the protease was not required to protect A506 from antibiosis. These data highlight a previously unknown role of the extracellular protease produced by Pseudomonas fluorescens A506 in interactions among plant-associated microbes.
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Long, Richard A., Asfia Qureshi, D. John Faulkner, and Farooq Azam. "2-n-Pentyl-4-Quinolinol Produced by a Marine Alteromonas sp. and Its Potential Ecological and Biogeochemical Roles." Applied and Environmental Microbiology 69, no. 1 (January 2003): 568–76. http://dx.doi.org/10.1128/aem.69.1.568-576.2003.
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ABSTRACT Bacterium-bacterium interactions occur at intimate spatial scales on the order of micrometers, but our knowledge of interactions at this level is rudimentary. Antagonism is a potential interaction in such microenvironments. To study the ecological role of antibiosis, we developed a model system involving an antibiotic-producing isolate (SWAT5) derived from a marine particle and its dominant antibiotic product, 2-n-pentyl-4-quinolinol (PQ). This system was used to address questions about the significance of this antibiotic for microbial ecology and carbon cycling on particles. We characterized the chemical and inhibitory properties of PQ in relation to the mechanisms used by particle-associated bacteria in interacting with particles and with other attached bacteria. PQ was produced by SWAT5 only on surfaces. When SWAT5 was grown in polysaccharide matrices, PQ diffused within the matrices but not into the surrounding seawater. SWAT5 might thus be able to generate a localized zone of high antibiotic concentration on particles suspended or sinking through seawater. Target bacterial respiration was most sensitive to PQ (75 nM), while inhibition of DNA synthesis, protein synthesis, and bacterial motility required higher (micromolar) PQ levels. The presence of PQ altered the composition of the bacterial community that colonized and developed in a model particle system. PQ also inhibited Synechococcus and phytoplankton growth. Our results suggest that antibiosis may significantly influence community composition and activities of attached bacterial and thus regulate the biogeochemical fate of particulate organic matter in the ocean.
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Wright, Sandra A. I., Cathy H. Zumoff, Lois Schneider, and Steven V. Beer. "Pantoea agglomerans Strain EH318 Produces Two Antibiotics That Inhibit Erwinia amylovoraIn Vitro." Applied and Environmental Microbiology 67, no. 1 (January 1, 2001): 284–92. http://dx.doi.org/10.1128/aem.67.1.284-292.2001.
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ABSTRACT Pantoea agglomerans (synonym: Erwinia herbicola) strain Eh318 produces through antibiosis a complex zone of inhibited growth in an overlay seeded with Erwinia amylovora, the causal agent of fire blight. This zone is caused by two antibiotics, named pantocin A and B. Using a genomic library of Eh318, two cosmids, pCPP702 and pCPP704, were identified that conferred on Escherichia coli the ability to inhibit growth ofE. amylovora. The two cosmids conferred different antibiotic activities on E. coli DH5α and had distinct restriction enzyme profiles. A smaller, antibiotic-conferring DNA segment from each cosmid was cloned. Each subclone was characterized and mutagenized with transposons to generate clones that were deficient in conferring pantocin A and B production, respectively. Mutated subclones were introduced into Eh318 to create three antibiotic-defective marker exchange mutants: strain Eh421 (pantocin A deficient); strain Eh439 (pantocin B deficient), and Eh440 (deficient in both pantocins). Cross-hybridization results, restriction maps, and spectrum-of-activity data using the subclones and marker exchange mutants, supported the presence of two distinct antibiotics, pantocin A and pantocin B, whose biosynthetic genes were present in pCPP702 and pCPP704, respectively. The structure of pantocin A is unknown, whereas that of pantocin B has been determined as (R)-N-[((S)-2-amino-propanoylamino)-methyl]-2-methanesulfonyl-succinamic acid. The two pantocins mainly affect other enteric bacteria, based on limited testing.
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Bansal, Raman, M. A. Rouf Mian, and Andy Michel. "Characterizing Resistance to Soybean Aphid (Hemiptera: Aphididae): Antibiosis and Antixenosis Assessment." Journal of Economic Entomology 114, no. 3 (March 24, 2021): 1329–35. http://dx.doi.org/10.1093/jee/toab038.
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Abstract Host-plant resistance (HPR) remains a vital tool to manage soybean aphid (Aphis glycines Matsumura), a major pest of soybean in Midwestern United States and southern Canada. HPR can be overcome by virulent biotypes of A. glycines; thus, in order to increase the durability of resistant cultivars, HPR needs to be deployed strategically. To improve the strategic deployment, a complete understanding of HPR in existing resistant germplasm will help ensure HPR success. In this study, we characterized HPR soybean to determine antibiosis and antixenosis categories of resistance to different biotypes of A. glycines. No-choice and free-choice tests were performed on 11 previously reported plant introductions (PIs) possessing resistance to at least one A. glycines biotype (1, 2, and 3). Overall, we found that the PIs manifested differences of a particular resistance category in response to infestation by different biotypes. Our data from no-choice tests indicate that all tested PIs possess antibiosis-based resistance to three biotypes. However, the strength of antibiosis was variable as some PIs showed stronger antibiosis toward a given biotype than others. All tested PIs manifested antixenosis, in addition to antibiosis. Furthermore, detached leaf assays revealed that resistance to A. glycines was not retained in excised soybean leaves. Characterization of resistance in this study can contribute to develop strategies for future deployment of resistant cultivars developed from these PIs.
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Muhibuddin, Anton, Syauqina Salsabila, and Antok Wahyu Sektiono. "KEMAMPUAN ANTAGONIS Tricoderma harzianum TERHADAP BEBERAPA JAMUR PATOGEN PENYAKIT TANAMAN." AGROSAINTIFIKA 4, no. 1 (November 30, 2021): 225–33. http://dx.doi.org/10.32764/agrosaintifika.v4i1.2371.
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Diseases that often attack plants are diseases caused by fungal pathogens causing stress such as fusarium wilt disease caused by Fusarium oxysporum, Alternaria solani, Rhizoctonia solani and Sclerotium rolfsii. One alternative to reduce these pathogens is Trichoderma harzianum. This study aims to determine the potential antibiosis antagonist characteristics of the fungus Trichoderma harzianum against several disease-causing pathogens in plants and the class of compounds contained therein.The method used in this research is experimental and descriptive. Experimental research was conducted by testing the fungus Trichoderma harzianum against several pathogenic fungi as an antibiosis. Then proceed to test the class of compounds using a phytochemical test on the filtrate of the secondary metabolites of Trichoderma harzianum. The results of the potential antibiosis antagonist test on the fungus Trichoderma harzianum showed the results of the antibiosis against the pathogenic fungi Fusarium oxysporum and the fungus Alternaria solani, but on the fungus Rhizoctonia solani and the fungus Sclerotium rolfsii, the results showed the presence of potential antibiosis followed by competition and parasitism. Inhibition on the seventh day of observation showed results of 79% against Fusarium oxysporum, 69% against Sclerotium rolfsii, 61% against Alternaria solani, and 59% against Rhizoctonia solani. Furthermore, for the phytochemical test, the filtrate of Trichoderma harzianum fungus showed positive content of alkaloids, flavonoids, steroids, and saponins.
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Weber, Daniela, Paul A. Egan, Anne Muola, and Johan A. Stenberg. "Genetic variation in herbivore resistance within a strawberry crop wild relative (Fragaria vesca L.)." Arthropod-Plant Interactions 14, no. 1 (November 9, 2019): 31–40. http://dx.doi.org/10.1007/s11829-019-09724-w.
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Abstract To decrease the dependency on chemical pesticides, the resistance of cultivated strawberry to pests needs to be increased. While genetic resources within domesticated varieties are limited, wild genotypes are predicted to show high heritable variation in useful resistance traits. We collected 86 wild accessions of Fragaria vesca L. from central Sweden and screened this germplasm for antibiosis (pest survival and performance) and antixenosis (pest preference) traits active against the strawberry leaf beetle (Galerucella tenella L.). First, extensive common garden experiments were used to study antibiosis traits in the sampled plant genotypes. Heritable genetic variation among plant genotypes was found for several antibiosis traits. Second, controlled cafeteria experiments were used to test for plant genetic variation in antixenosis traits. The leaf beetles avoided egg laying on plant genotypes possessing high antibiosis. This indicates a high degree of concordance between antibiosis and antixenosis and that the beetles’ egg-laying behavior optimizes the fitness of their offspring. The existence of high genetic variation in key resistance traits suggests that wild woodland strawberry contains untapped resources that are sought to reduce pesticide dependence in cultivated strawberry. Given that only a very small portion of the species’ distribution area was sampled, even higher variation may be expected at the continental scale. As a whole, the genetic resources identified in this study serve to strengthen the position of woodland strawberry as a key crop wild relative.
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Migui, S. M., and R. J. Lamb. "Seedling and adult plant resistance to Sitobion avenae (Hemiptera: Aphididae) in Triticum monococcum (Poaceae), an ancestor of wheat." Bulletin of Entomological Research 94, no. 1 (February 2004): 35–46. http://dx.doi.org/10.1079/ber2003278.
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AbstractCereal aphids are important pests of wheat, Triticum aestivum L. and Triticum durum Desf. Crop resistance is a desirable method for managing cereal aphids in central North America, where the dominant crop, spring-sown wheat, has a low value per unit area. A diploid ancestor of wheat, Triticum monococcum L., is reported to be partially resistant to Sitobion avenae (Fabricius), the most damaging cereal aphid in the region. To identify potential sources of resistance, 42 accessions of T. monococcum and three cultivated wheats were infested with aphids, seedlings for six days and adult plants for 21 days. Overall resistance was estimated by the biomass loss of foliage and spikes in relation to uninfested control plants. Antibiosis was estimated by the gain in biomass of aphids during infestation, and tolerance was estimated as a biomass conversion ratio, overall resistance divided by antibiosis. A few T. monococcum accessions exhibited partial resistance. No relationship was found between seedling and adult plant resistance: the former exhibited primarily antibiosis and the latter primarily tolerance. Two accessions with antibiosis reduced aphid biomass by 60% compared with commercial wheats. Tolerance was correlated with growth potential, and was useful only in accessions with high growth potential. Four accessions exhibited tolerance levels at least 30% greater than commercial wheats. Highly susceptible accessions also were identified, which would be useful for investigating the inheritance of antibiosis and tolerance.
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Bosland, Paul W., and John J. Ellington. "Comparison of Capsicum annuum and C. pubescens for Antixenosis as a Means of Aphid Resistance." HortScience 31, no. 6 (October 1996): 1017–18. http://dx.doi.org/10.21273/hortsci.31.6.1017.
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Accessions of Capsicum annuum L., a susceptible host, and C. pubescens (R. & P.), a resistant host, were grown in a replicated greenhouse study to test whether antixenosis (nonpreference), antibiosis, or both was the mechanism for resistance to green peach aphid [Myzus persicae (Sulzer)]. A plant choice experiment established that aphids preferred C. annuum to C. pubescens. A no-plant choice test was not undertaken; nevertheless, the aphid's reproductive rates were measured in leaf containment cages and were similar on both hosts. The mechanism of antibiosis was not indicated because fecundity was not reduced in the containment cages; however, other measures of antibiosis were not studied. These observations suggest that antixenosis may be functioning in C. pubescens.
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Maritsa, Hasnaul, and Hesti Riany. "SCREENING ANTAGONISTIK ACTINOBACTERIA SEBAGAI AGEN BIOKONTROL TERHADAP Ganoderma boninense." Jurnal Silva Tropika 6, no. 1 (June 30, 2022): 60–67. http://dx.doi.org/10.22437/jsilvtrop.v6i1.23471.
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ABSTRACT Actinobacteria (Actinomycetes) is a unique group among microbe and prokaryotes. They have both characteristics of fungi and bacteria. Actinobacteria could produce a wide range of secondary metabolites such as antibiotics, antifungal, antiprotozoal, antiviral, anticholesterol, antihelminth, anticancer, and immunosuppressant. It may cause a better combination as a biocontrol agent for plants. This research aimed to investigating potential actinomycetes as biocontrol agents of fungal plant pathogens, especially Ganoderma boninense. The method in this research consists of a few steps. Those are samples collection from soil and water in the primer forest and plantation soil (palm oil), samples isolation, actinobacteria characterization, and evaluation of the antifungal activity. The result has shown that 29 fungal isolates were found in this study. The percent growth inhibition (PGI) of actinobacteria isolates variated from 0-81,58%. And their inhibition mechanisms were antibiosis and competition. Keywords: actinomycetes, antimicrobial, fungal plant pathogen ABSTRAK Actinobacteria (Actinomycetes) adalah kelompok unik dari kelompok mikroba dan prokariota. Actinobacteria memiliki karakteristik jamur dan bakteri dan dapat menghasilkan berbagai metabolit sekunder seperti antibiotik, antijamur, antiprotozoal, antivirus, antikolesterol, antihelminth, antikanker, serta imunosupresan. Kemampuanya ini dapat dimanfaatkan untuk campuran pada agen biokontrol tanaman. Penelitian ini bertujuan untuk mengetahui potensi aktinomisetes sebagai agen biokontrol jamur patogen tanaman, khususnya Ganoderma boninense. Metode dalam penelitian ini terdiri dari beberapa langkah, yaitu pengambilan sampel dari tanah dan air di hutan primer dan tanah perkebunan (kelapa sawit), isolasi sampel, karakterisasi aktinobakteri, dan evaluasi aktivitas antijamur. Hasil penelitian ini menunjukkan bahwa 29 isolat jamur yang ditemukan. Persentase hambatan pertumbuhan (PGI) isolat aktinobakteri bervariasi antara 0-81,58%. Dan mekanisme penghambatannya adalah antibiosis dan kompetisi. Kata kunci: actinomycetes, antimikroba, jamur patogen tanaman
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Wehner, Todd C., Kent D. Elsey, and George G. Kennedy. "Screening for Cucumber Antibiosis to Pickleworm." HortScience 20, no. 6 (December 1985): 1117–19. http://dx.doi.org/10.21273/hortsci.20.6.1117.
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Abstract A detached-leaf test was used to screen a cucumber (Cucumis sativus L.) germplasm collection for antibiosis to the pickleworm (Diaphania nitidalis Stoll.). Data were collected on 1160 lines planted in the field in 1981. The 36 most resistant and 36 most susceptible lines were retested with improved methods, reducing the number of lines to 8 and finally to 6 based on leaf damage by pickleworm larvae. Selections were made within those lines to stabilize the resistant or susceptible reaction of each line in our test. In a final test, no significant differences were found among the selections, which included the most resistant and most susceptible lines identified in all studies. A heritability study was run on a population produced by intercrossing the 5 most resistant and 3 most susceptible lines identified in the initial field screening for 3 generations. Parent-offspring regression was used to estimate a narrow-sense heri-tablity of 0.03. Thus, there was little or no genetic variation in cucumber for antibiosis to pickleworm larvae, and other methods of control should be used.
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Prochacki, H. "Observations on the Antibiosis of Dermatophytes." Mycoses 12, no. 6 (April 24, 2009): 353–58. http://dx.doi.org/10.1111/j.1439-0507.1969.tb03916.x.
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Assabgui, R. A., J. T. Arnason, and R. I. Hamilton. "Hydroxamic acid content in maize (Zea mays) roots of 18 Ontario recommended hybrids and prediction of antibiosis to the western corn rootworm, Diabrotica virgifera virgifera LeConte [Coleoptera: Chrysomelidae]." Canadian Journal of Plant Science 73, no. 1 (January 1, 1993): 359–63. http://dx.doi.org/10.4141/cjps93-053.
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High performance liquid chromatography was used to assess concentrations of hydroxamic acids in maize root extracts of 18 greenhouse-grown hybrids recommended in Ontario. On the basis of hydroxamic acid concentrations, low-level antibiosis against the western corn rootworm, Diabrotica virgifera virgifera LeConte was predicted for the majority of these (1990) hybrids, when grown under field conditions. Key words: Antibiosis, Chrysomelidae, Diabrotica, DIMBOA, hydroxamic acids, maize hybrids
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Suryaminarsih, Penta, Tri Mujoko, K. Gusriyan, Fitri Wijayanti, and Salmah Mohammad. "Study of antibiosis of Streptomyces sp. from the land of shallot plants as biological agents of Fusariumsp. cause of Twisted diseases (Moler)." IOP Conference Series: Earth and Environmental Science 1131, no. 1 (January 1, 2023): 012017. http://dx.doi.org/10.1088/1755-1315/1131/1/012017.
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Abstract The use of bio pesticides and organic pesticides from secondary metabolic filtrate of APH microorganisms is one of the food and horticulture cultivation technology packages which are the basis for this research objective. The research objective was to explore, isolate and identify of Streptomyces sp. in the land of shallot plants (Abm) and the antibiosis against the pathogens Fusariumsp cause of Moler shallot plant in vitro. Observer of Quality and quantity characteristics of secondary metabolites as antibiosis, The results showed that Streptomyces sp from land of shallot plant (Abm) isolates producing little antibiosis less able to inhibit the development of the pathogens Fusariumsp cause of Moler shallot plant in vitro. The identification of Actinomycetes spp. based on the morphology characteristic showed that Actinomycetes isolates are closely related with Streptomyces sp.
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Aguirre-Rojas, Lina M., Lawrent L. Buschman, Brian McCornack, William T. Schapaugh, Erin D. Scully, Kun Yan Zhu, Harold N. Trick, and Charles Michael Smith. "Inheritance of Antibiosis Resistance to the Dectes Stem Borer, Dectes texanus, in Soybean PI165673." Agronomy 11, no. 4 (April 10, 2021): 738. http://dx.doi.org/10.3390/agronomy11040738.
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Dectes texanus larvae girdles the stems of soybean and cultivated sunflowers causing significant yield losses in North America. The soybean Plant Introduction (PI) 165673 exhibits antibiosis resistance to the larval stage. The objectives of this study were: (1) to determine the inheritance of D. texanus resistance in PI165673; (2) evaluate PI165673 antibiosis resistance before 21 d post infestation; (3) evaluate girdling damage in PI16563 at the end of the season. K07-1544/PI165673 F2 and F2:3 populations were tested for resistance to D. texanus in 2011 and 2012, and PI165673 antibiosis resistance and girdling damage were evaluated in 2014. Segregation for resistance to D. texanus and heritability estimates in the F2 and F2:3 populations indicated that resistance was controlled by two genes with dominant and recessive epistasis. Antibiosis evaluations indicated: (1) PI165673 contained lower number of larvae and eggs relative to the number of oviposition punctures at 15 d post infestation; (2) the proportion of first-instar larvae was higher in PI165673 at 15 d post infestation; (3) larvae reach the sixth-instar stage in PI165673. None of the PI165673 plants were girdled at the end of the season. Identification of additional sources of D. texanus resistance is required to impair larval development in the stem.
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Wood, Bruce W., and Charles C. Reilly. "Nature of Resistance of Pecan Cultivars to Black Pecan Aphids." HortScience 32, no. 3 (June 1997): 441D—441. http://dx.doi.org/10.21273/hortsci.32.3.441d.
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Foliar feeding by the black pecan aphid [Melanocallis caryaefoliae (Davis)] can cause tremendous economic losses. Evaluations of black aphids on pecan genotypes indicates that both antixenosis and antibiosis-like resistance mechanisms exists. Tests for antixenosis indicated that aphids possess clear preferences for certain genotypes over others and that this preference can be dependent on a water-soluble chemical component of the leaf surface. Aphids also exhibited a “conditioning preference,” in which they preferentially feed on genotypes from which they originated. Antibiosis tests indicated that pecan genotypes influence the reproductive success of aphids already possessing a feeding adaptation to those same pecan genotypes; therefore, an evaluation of 30 cultivars for antibiosis indicated that populations developed only 20% as fast on `Choctaw' and `Alley' as on `Desirable' and `Success'. No cultivar was observed to essentially prevent aphid reproduction.
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Mei, Chuansheng, B. Sajeewa Amaradasa, Robert L. Chretien, Danyang Liu, George Snead, Jayesh B. Samtani, and Scott Lowman. "A Potential Application of Endophytic Bacteria in Strawberry Production." Horticulturae 7, no. 11 (November 18, 2021): 504. http://dx.doi.org/10.3390/horticulturae7110504.
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Endophytic bacteria could be used as a tool to promote plant growth, enhance abiotic stress tolerance, and inhibit plant pathogen growth. More than 100 bacteria, previously tested to have biocontrol activity against fungal pathogens from our lab, were chosen for pathogen inhibition in vitro with antibiosis assays against strawberry specific pathogens. Three potential endophytic bacteria were tested in the greenhouse for disease reduction and growth performance. Finally, field trials were conducted for fruit yield production. Our results showed that three endophytic bacteria significantly inhibited the growth of the strawberry pathogen Colletotrichum gloeosporioides from antibiosis assays and were identified as Bacillus velezensis strains IALR308, IALR585, and IALR619. Inoculation of these bacteria significantly reduced strawberry disease in greenhouse conditions with pathogen infection. Field trials showed that IALR619 has potential to influence marketable fruit yield when strawberry plants were inoculated twice over the growing season. All three bacteria had the ability to produce auxin and to solubilize phosphate. The antibiotics surfactin and iturin were also detected in IALR585 and IALR619. In conclusion, Bacillus velezensis IALR619 has potential inhibition of strawberry pathogen growth in the greenhouse and possible ability to increase marketable fruit yield in the field.
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Neeno-Eckwall, Eric C., Linda L. Kinkel, and Janet L. Schottel. "Competition and antibiosis in the biological control of potato scab." Canadian Journal of Microbiology 47, no. 4 (April 1, 2001): 332–40. http://dx.doi.org/10.1139/w01-010.
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Nonpathogenic, antibiotic-producing streptomycetes have been shown to reduce potato scab when added to disease-conducive soil. Spontaneous mutants of the pathogenic Streptomyces scabies RB4 that are resistant to at least one antibiotic activity produced by the nonpathogenic suppressive isolates Streptomyces diastatochromogenes strain PonSSII and S. scabies PonR have been isolated. To determine the importance of antibiosis in this biocontrol system, these mutants were investigated for their ability to cause disease in the presence of the two pathogen antagonists in a greenhouse assay. Disease caused by one of the mutant strains was reduced in the presence of both suppressive isolates, whereas disease caused by the other five mutants was not significantly reduced by either suppressive strain. In addition, a nonpathogenic mutant of S. scabies RB4 was isolated, which produced no detectable in vitro antibiotic activity and reduced disease caused by its pathogenic parent strain when the pathogen and mutant were coinoculated into soil. Population densities of the pathogen were consistently lower than those of the suppressive strains when individual strains were inoculated into soil. When a pathogen was coinoculated with a suppressive strain, the total streptomycete population density in the pot was always less than that observed when the suppressive isolate was inoculated alone. When the pathogens were inoculated individually into soil, a positive correlation was seen between population density and disease severity. In coinoculation experiments with pathogen and suppressive strains, higher total streptomycete population densities were correlated with lower amounts of disease.Key words: Streptomyces scabies, biological control, antibiotic resistance, potato scab disease.