Project description:Stem rust of wheat is a deleterious fungal disease across the globe causing severe yield losses. Although, many stem rust resistance genes (Sr) are being used in wheat breeding programs, new emerging stem rust pathotypes are a challenge to important Sr genes. In recent years, multiple studies on leaf and yellow rust molecular mechanism have been done, however, for stem rust such studies are lacking. Current study investigated stem rust induced response in the susceptible wheat genotype C306 and its Near Isogenic Line (NIL) for Sr24 gene, HW2004, using microarray analysis to understand the transcriptomic differences at different stages of infection. Results showed that HW2004 has higher basal levels of several important genes involved in pathogen detection, defence, and display early activation of multiple defence mechanisms. Further Gene Ontology (GO) and pathway analysis identified important genes responsible for pathogen detection, downstream signalling cascades and transcription factors (TFs) involved in activation and mediation of defence responses. Results suggest that generation of Reactive Oxygen Species (ROS), cytoskeletal rearrangement, activation of multiple hydrolases, and lipid metabolism mediated biosynthesis of certain secondary metabolites are collectively involved in Sr24-mediated defence in HW2004, in response to stem rust infection. Novel and unannotated, but highly responsive genes were also identified, which may also contribute towards resistance phenotype. Furthermore, certain DEGs also mapped close to the Sr24-linked marker on Thinopyrum elongatum translocated fragment on wheat 3E chromosome, which advocate further investigations for better insights of the Sr24-mediated stem rust resistance.
Project description:Switchgrass (Panicum virgatum) can be infected by the rust pathogen (Puccinia novopanici) resulting in lowering biomass yields and quality. Here, two cultivars with divergent rust resistance were used to evaluate the dynamic changes in proteomes following rust inoculation. Label-free quantitative proteomics was conducted on leaf extracts harvested from a susceptible cultivar Summer at 7, 11, and 18 DAI, and leaves collected at 18 DAI from controls and infected plants of the more resistant cultivar Kanlow.
Project description:Eucalyptus rust is caused by the biotrophic fungus, Austropuccinia psidii, which affects commercial plantations of Eucalyptus, a major raw material for the pulp and paper industry in Brazil. Aiming to uncover the molecular mechanisms involved in rust resistance and susceptibility in Eucalyptus grandis, we used epifluorescence microscopy to follow the fungus development inside the leaves of two contrasting half-sibling genotypes (rust-resistance and rust-susceptible), to determine the time-course for comparative metabolomic and proteomic analyses in plantlets artificially inoculated with rust. Within 24 hours of complete fungal invasion, a total of 709 plant metabolites showed that the rust-resistant genotype suppressed many metabolites 6 hours after inoculation (hai), with responses being progressively induced after 12 hai. In contrast, the rust-susceptible genotype displayed an alternated metabolite response to infection, which culminated in a strong suppression at 24 hai. Multivariate analyses of genotypes and time points were used to select 16 differential metabolites chemically classified as flavonoids, benzenoids and other compounds. Applying the Weighted Gene Co-Expression Network Analysis (WGCNA), rust-resistant and rust-susceptible genotypes had, respectively, 871 and 852 proteins grouped into 14 and 13 modules, of which 10 and 7 protein modules were significantly correlated to the selected metabolites. Functional analyses revealed roles for oxidative-dependent responses leading to temporal activity of metabolites and proteins after 12 hai in rust-resistance, while the initial over-accumulation of metabolites and correlated proteins caused a lack of progressive response after 12 hai in rust-susceptible genotype. This study provides a brief understand on the temporal divergences of resistant and susceptible molecular responses of E. grandis plants to rust.
Project description:To investigate the molecular mechanism of nonhost resistance of M. truncatula against soybean rust, we performed integrated tanscriptome and metabolome analyses using samples derived from M. truncatula leaves inoculated with soybean rust. To identify host signaling pathways triggered by soybean rust infection, we carried out microarray analysis to monitor the expression profiles associated with nonhost resistance including pre-invasive (12 hai) and apoplastic defense (24 hai) using Affymetrix GeneChip® Medicago Genome Array (Affymetrix).
Project description:Transcriptional profiling of rust-infected pearl millet seedlings over time [0h, 20h, 5d and 8d post infection (pi)]. Keywords: Time course, Stress response
Project description:Two sets of wheat lines near-isogenic to Lr34 were used to compare gene expression profiles of wheat: 1. with and without Lr34 gene; 2. rust and mock inoculation; 3. distal and basal portion of the flag leaves. The two sets of wheat near-isogenic lines were used to subtract genetic background variations and to enrich Lr34-regulated gene expression profiles. The study is aimed to better understand the mechanisms of the well-known durable leaf rust resistance gene, Lr34, mediated resistance at the transcriptome level. Keywords: Distal and basal leaf halves of near-isogenic lines
Project description:Transcriptional profiling of rust-infected pearl millet seedlings over time [0h, 20h, 5d and 8d post infection (pi)]. Keywords: Time course, Stress response Loop design. All time points compared with time = 0 h in data analysis. Two biological replicates per sample, and one technical dye swap replicate.
Project description:One week old bread wheat plantlets were artifically infected with Puccinia triticinae (the causal organism of wheat leaf rust) and samples were collected after one week from infection. Samples were collected after one week from infection, non infected as well. Two loacl varities were used MISR 1 and GEMMZA 7.