Project description:Arabidopsis thaliana genes MLO2 (Mildew resistance locus-O 2), MLO6 and MLO12 exhibit unequal genetic redundancy with respect to the modulation of defense responses against powdery mildew fungi and the control of developmental phenotypes such as premature leaf decay. We show that early chlorosis and necrosis of rosette leaves in mlo2 mlo6 mlo12 mutants reflects an authentic but untimely leaf senescence program. Comparative transcriptional profiling revealed that transcripts of several genes encoding tryptophan/indole biosynthetic enzymes hyper-accumulate during vegetative development in the mlo2 mlo6 mlo12 mutant. Elevated expression levels of these genes correlate with altered steady-state levels of several indolic metabolites, including the phytoalexin camalexin and indolic glucosinolates, during development in the mlo2 single and the mlo2 mlo6 mlo12 triple mutant. Results of genetic epistasis analysis suggest a decisive role for indolic metabolites in mlo2-conditioned antifungal defense against both biotrophic powdery mildews and a camalexin-sensitive strain of the necrotrophic fungus, Botrytis cinerea. The wound- and pathogen-responsive callose synthase Powdery mildew resistance 4/Glucan-synthase-like 5 (PMR4/GSL5) was found to be responsible for the spontaneous callose deposits in mlo2 mutant plants but dispensable for mlo2-conditioned penetration resistance. Our data strengthen the notion that powdery mildew resistance of mlo2 genotypes is based on the same defense execution machinery as innate antifungal immune responses that restrict invasion of non-adapted fungal pathogens.
Project description:We used two wheat genotypes, the susceptible wheat cultivar ‘8866 ’(S) and its near isogenic line with single powdery mildew resistance gene ‘pm30’ (R), to investigate gene expression changes in response to powdery mildew infection by using Wheat Genome Array
Project description:We generated ChIP-Seq data for two barley accessions with different resistance to powdery mildew. These data allowed us to explore the roles of epigenetic modifications in resistance response to powdery mildew at the first time. Our study opens the way for establishing the relationship between epigenetics and disease response in barley, and should inform future functional characterization of the regarding molecular basis. These data should also help researchers to exploit disease response-related genes for breeding application.
Project description:Arabidopsis thaliana genes MLO2 (Mildew resistance locus-O 2), MLO6 and MLO12 exhibit unequal genetic redundancy with respect to the modulation of defense responses against powdery mildew fungi and the control of developmental phenotypes such as premature leaf decay. We show that early chlorosis and necrosis of rosette leaves in mlo2 mlo6 mlo12 mutants reflects an authentic but untimely leaf senescence program. Comparative transcriptional profiling revealed that transcripts of several genes encoding tryptophan/indole biosynthetic enzymes hyper-accumulate during vegetative development in the mlo2 mlo6 mlo12 mutant. Elevated expression levels of these genes correlate with altered steady-state levels of several indolic metabolites, including the phytoalexin camalexin and indolic glucosinolates, during development in the mlo2 single and the mlo2 mlo6 mlo12 triple mutant. Results of genetic epistasis analysis suggest a decisive role for indolic metabolites in mlo2-conditioned antifungal defense against both biotrophic powdery mildews and a camalexin-sensitive strain of the necrotrophic fungus, Botrytis cinerea. The wound- and pathogen-responsive callose synthase Powdery mildew resistance 4/Glucan-synthase-like 5 (PMR4/GSL5) was found to be responsible for the spontaneous callose deposits in mlo2 mutant plants but dispensable for mlo2-conditioned penetration resistance. Our data strengthen the notion that powdery mildew resistance of mlo2 genotypes is based on the same defense execution machinery as innate antifungal immune responses that restrict invasion of non-adapted fungal pathogens. Mature rosette leaves from WT and mlo2 mlo6 mlo12 triple mutant plants were harvested at 5, 6 and 7 weeks after sowing. 6 arrays.
Project description:It has been demonstrated that wheat overexpressing Pm3b, an allele of the R gene Pm3, has enhanced resistance against powdery mildew under field conditions. A gene expression profile study using GeneChip® Wheat Genome Array was performed to obtain insights into the mode of action of Pm3b and to elucidate the molecular basis of pleiotropic effects observed in three out of four independent transgenic events tested under field conditions. 24 samples were analyzed. Three biological replicates of each sample were included. Two independent transformation events and respective null segregants as control treated with fungicide or artificially inoculated with powdery mildew.
Project description:We used two wheat genotypes, the susceptible wheat cultivar ‘8866 ’(S) and its near isogenic line with single powdery mildew resistance gene ‘pm30’ (R), to investigate gene expression changes in response to powdery mildew infection by using Wheat Genome Array wheat young leveas of near isogenic lines before or 12 hours after powdery mildew infection were selected for RNA extraction and hybridization on Affymetrix microarrays.The leaf samples were harvested from three independent biological replicates, and the leaves without inoculation were regarded as control.
Project description:The edr1 mutant of Arabidopsis thaliana displays enhanced resistance to the powdery mildew Golovinomyces cichoracearum, resulting in cell death and an absence of visible disease symptoms. To better characterize and understand the defense response of edr1, a time course of early signaling responses was performed after inoculation with powdery mildew and compared to the responses of wild-type Col-0. These time points represent early stages in the infection process, before any signs of susceptibility or resistance are visible.
Project description:Powdery mildew caused by Erysiphe cruciferarum, is an epidemic of oil rapeseed (Brassica napus) growing worldwide, but resistant germplasm is rare in this species. We obtained the hybrid seeds of distant hybridization between powdery-mildew-immune Brassica carinata cultivar ‘White flower’ and susceptible B. napus cultivar ‘Zhongshuang11’. Five lines in the BC1F3 generation (F3 after backcross to 'Zhongshuang11') were identified to be resistant or moderately resistant. In order to identify the important biological responses to powdery mildew, the foliar transcriptomes of the resistant and susceptible plants in these progenies after powdery mildew inoculation were compared by using Illumina RNA-seq. We identified 10,454 differential expression genes (DEGs) and 1050 genes out of them are related to disease resistance. There were 271 DEGs in Group Resistance expressed at least two fold higher than in group S, while 779 DGEs expressed two fold lower. The genes highly expressed in Group Resistance are those encoding the proteins: (1) related to wax, chloroplast and cell wall metabolism, such as KCS6, CSP41B, RWA, callose synthetase 3, pectinase 9, fructosidase 2, 9s-lipoxygenase LOX2, etc.; (2) kinases including RKL, ERECTA, BAK1, BAM2, LysM receptor like kinase, and lipid transfer protein kinase ERl1 and ERl2; (3) broad spectrum powdery mildew resistance proteins RPW8, calmodulin MLO2, PMR5, MLP328, EDR2, RPS4 and RPS6, etc. In group susceptible, pectinesterase, cytochrome CYP81f2, LOX1, cysteine rich receptor protein kinases and serine / threonine protein kinases such as MEKK, RLK6, CRK45, APK1, BRl3, WAK1, WAK10, etc., and TIR-NB-LRR receptor like proteins R1M1, DSC1, DSC2 and pathogenesis-related protein PR-1 etc. were the most activated genes. The results provide the preliminarily knowledge about molecular mechanism in rapeseed defense response to powdery mildew.
Project description:The edr1 mutant of Arabidopsis thaliana displays enhanced resistance to the powdery mildew Golovinomyces cichoracearum, resulting in cell death and an absence of visible disease symptoms. To better characterize and understand the defense response of edr1, a time course of early signaling responses was performed after inoculation with powdery mildew and compared to the responses of wild-type Col-0. These time points represent early stages in the infection process, before any signs of susceptibility or resistance are visible. Four-week-old Col-0 and edr1 plants were inoculated with powdery mildew and whole rosettes were collected at 0, 18, 36, and 96 hours post inoculation. Each sample is a pool of four rosettes processed together.
Project description:To investigate the candidate genes governing Pm5.1 and their effects on powdery resistance, the RNA-sequencing based transcriptomes of the powdery mildew resistant segment substitution line SSL508-28 and recurrent parent D8 were compared 48 h after inoculation with the PM pathogen.