Search results for "RESISTANCE"
showing 10 items of 3641 documents
From glacial refugia to hydrological microrefugia: Factors and processes driving the persistence of the climate relict tree Zelkova sicula
2021
Abstract With only two tiny populations, the climate relict Zelkova sicula (Sicily, Italy) is one of the rarest trees in the world. It also represents the most marginal member of genus Zelkova that was widespread in the broadleaved forests thriving in warm–temperate climates throughout Eurasia until the Last Glacial Age. Occurring at the westernmost range of the genus under typical Mediterranean climate, the micro‐topographic settings have always appeared crucial for the survival of this relict. However, the factors and processes actually involved in its persistence in the current refugia, as well as the response of similar relict trees in arid environments, are poorly understood worldwide.…
Cellular encapsulation in the eastern subterranean termite, Reticulitermes flavipes (Isoptera), against infection by the entomopathogenic fungus Meta…
2009
Reticulitermes flavipes workers were topically inoculated with approximately 10,000 conidia of the entomopathogenic fungus Metarhizium anisopliae. After being kept in groups of 20 individuals for 1-9 d, histopathological examination showed that termites had an individual immune reaction. The nodule formation at the point of entrance of the fungal hyphae was identified as a cellular encapsulation and the different steps in the nodule formation are described. The relative number of hemocytes per termite increased 24h after fungal exposure and remained high in the hemolymph for at least 3 d before decreasing back to pre-exposure levels. The role of an individual immune cellular reaction in soc…
Image analysis methods for assessment of H2O2 production and Plasmopara viticola development in grapevine leaves: application to the evaluation of re…
2013
article i nfo The grapevine downy mildew (Plasmopara viticola) provokes severe damages and destroys the harvest in the absence of an effective protection. Numerous fungicide treatments are thus generally necessary. To promote a sustainable production, alternative strategies of protection including new antifungal molecules, resistant geno- types or elicitor-induced resistance are under trial. To evaluate the relevance of these strategies, resistance tests are required. In this context, three image analysis methods were developed to read the results of tests performed to assessP.viticolasporulation and mycelial development, and H 2 O 2 production in leaves. They have been validated using elic…
Resistance of a recombinant Escherichia coli to dehydration.
2009
International audience; Dehydration of microorganisms, rendering them anhydrobiotic, is often an efficient method for the short and long term conservation of different strain-producers. However, some biotechnologically important recombinant bacterial strains are extremely sensitive to conventional treatment. We describe appropriate conditions during dehydration of the recombinant Escherichia coli strain HB 101 (GAPDH) that can result dry cells having a 88% viability on rehydration. The methods entails air-drying after addition of 100 mM trehalose to the cultivation medium or distilled water (for short term incubation).
Molecular Bases for Sensitivity to Tubulin-Binding Herbicides in Green Foxtail
2004
Abstract We investigated the molecular bases for resistance to several classes of herbicides that bind tubulins in green foxtail (Setaria viridis L. Beauv.). We identified two α- and two β-tubulin genes in green foxtail. Sequence comparison between resistant and sensitive plants revealed two mutations, a leucine-to-phenylalanine change at position 136 and a threonine-to-isoleucine change at position 239, in the gene encoding α2-tubulin. Association of mutation at position 239 with herbicide resistance was demonstrated using near-isogenic lines derived from interspecific pairings between green foxtail and foxtail millet (Setaria italica L. Beauv.), and herbicide sensitivity bioassays combine…
Evaluation of Nonpathogenic Fusarium oxysporum and Pseudomonas fluorescens for Panama Disease Control
2011
Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699; Nonpathogenic Fusarium oxysporum endophytes from healthy banana roots were evaluated for their ability to reduce Fusarium wilt of banana (Panama disease). Isolates were identified morphologically and by using species-specific primers. Pathogenicity was confirmed by inoculating banana plantlets in the greenhouse. Nonpathogenic F. oxysporum isolates were grouped into 14 haplotype groups by polymerase chain reaction restriction fragment length polymorphism analysis of the intergenic sp…
SNP markers for black-grass (Alopecurus myosuroides Huds.) genotypes resistant to Acetyl CoA-carboxylase inhibiting herbicides
2002
Chloroplastic acetyl CoA-carboxylase (ACCase) is the target of widely used, specific graminicide herbicides: cyclohexanediones (CHDs) and aryloxyphenoxypropionates (APPs). Resistance to these compounds is a worldwide, increasing problem. Population genetic studies aimed at understanding the dynamics of this situation and the diffusion of resistance genes within and between weed populations are challenging because biological assays are not adequate for this purpose, and because different mechanisms of resistance confer a similar resistance phenotype. Molecular markers for specifically detecting resistance genes are therefore urgently needed to conduct such studies. For this purpose, we clone…
The grapevine flagellin receptor VvFLS2 differentially recognizes flagellin-derived epitopes from the endophytic growth-promoting bacterium Burkholde…
2014
International audience; The role of flagellin perception in the context of plant beneficial bacteria still remains unclear. Here, we characterized the flagellin sensing system flg22-FLAGELLIN SENSING 2 (FLS2) in grapevine, and analyzed the flagellin perception in the interaction with the endophytic plant growth-promoting rhizobacterium (PGPR) Burkholderia phytofirmans. The functionality of the grapevine FLS2 receptor, VvFLS2, was demonstrated by complementation assays in the Arabidopsis thaliana fls2 mutant, which restored flg22-induced H2O2 production and growth inhibition. Using synthetic flg22 peptides from different bacterial origins, we compared recognition specificities between VvFLS2…
Glutathione deficiency of the Arabidopsis mutant pad2-1 affects oxidative stress-related events, defense gene expression and hypersensitive response
2011
L'article original est publié par The American Society of Plant Biologists; International audience; The Arabidopsis (Arabidopsis thaliana) phytoalexin-deficient mutant pad2-1 displays enhanced susceptibility to a broad range of pathogens and herbivorous insects that correlates with deficiencies in the production of camalexin, indole glucosinolates, and salicylic acid (SA). The pad2-1 mutation is localized in the GLUTAMATE-CYSTEINE LIGASE (GCL) gene encoding the first enzyme of glutathione biosynthesis. While pad2-1 glutathione deficiency is not caused by a decrease in GCL transcripts, analysis of GCL protein level revealed that pad2-1 plants contained only 48% of the wild-type protein amoun…
Physiological and Molecular Characteristics of Elicitin-Induced Systemic Acquired Resistance in Tobacco
1996
Elicitins are low molecular weight proteins secreted by all Phytophthora species analyzed so far. Application of the purified proteins to tobacco Nicotiana tabacum leads to the induction of resistance to subsequent inoculations with the black shank-causing agent, Phytophthora parasitica var nicotianae. In this paper, we describe the systemic characteristics of elicitin-induced acquired resistance in tobacco. Elicitin application is followed by the rapid translocation of the protein in the plant. The basic elicitin, cryptogein, induces necrosis formation in the leaves, which results from accumulation of the protein in these organs. Necrosis does not seem to be essential for the establishment…