Project description:Transcript changes in response to low temperature Total RNA for RNA-seq analysis were extracted from wheat leaf tissues with three biological replicates for each growth condition.
Project description:The wheat gene Lr34 confers partial resistance to all races of Puccinia triticina, the causal agent of wheat leaf rust. However, the biological basis for the exceptional durability of Lr34 is unclear. The Affymetrix wheat genome array was used to identify wheat genes differentially expressed in a compatible interaction (Tc), an R-gene mediated incompatible interaction (Tc-Lr1), and a race non-specific resistance interaction (Tc-Lr34) in response to infection challenge by P. triticina race 1 at anthesis. Transcriptome interrogation was conducted by comparing mock- and P. triticina-inoculated leaves harvested at 3 and 7 days post inoculation (dpi). SUBMITTER_CITATION: Bolton, M.D., Kolmer, J.A., Xu, W.W., and Garvin, D.F. 2008. Lr34-mediated leaf rust resistance in wheat: transcript profiling reveals a high energetic demand supported by transient recruitment of multiple metabolic pathways. Molecular Plant-Microbe Interactions 21:1515-1527. Experiment Overall Design: The Affymetrix wheat genome array was used to identify wheat genes differentially expressed in a compatible interaction (Tc), an R-gene mediated incompatible interaction (Tc-Lr1), and a race non-specific resistance interaction (Tc-Lr34) in response to infection challenge by P. triticina race 1 at anthesis. Transcriptome interrogation was conducted on leaves harvested at 3 and 7 days post inoculation (dpi). The study utilized a randomized complete block design with three replicates for each genotype, and employed univariate analysis (t-tests) between mock- and P. triticina-inoculated plants within each genotype at each timepoint, for a total of six comparisons across the entire experiment, utilizing a total 36 Affymetrix Wheat Genome Array GeneChips.
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: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.