Project description:Using a cDNA microarray themed on Ascochyta-Pulse interaction resistance response was studied in two lentil varieties, specifically in response to A. lentis inoculation in a highly resistant (ILL7537) and highly susceptible (ILL6002) lentil variety. The experiments were conducted in reference design, where samples from mock-inoculated controls acted as references against post-inoculation samples and the plants were grown using a uniform and standardized experimental system that minimized environmental effects. Robust and high quality data was obtained through the use of three biological replicates (including a dye-swap), the inclusion of negative controls, and stringent selection criteria for differentially expressed genes including a fold change cutoff determined by self-self hybridizations, Students t-test and FDR (Fasle Discovary Rate) multiple testing correction (P<0.05). Microarray observations were validated by quantitative real time RT-PCR using the RNA from one of the bioassay used in the original microarray experiment. Ninety genes were differentially expressed in ILL7537 and 95 genes were differentially expressed in ILL6002. The expression profiles of the two varieties showed substantial difference in type and time of genes that were expressed in response to A. lentis. The resistant variety showed early up-regulation of PR proteins and other defence related genes. The susceptible genotype showed mainly down-regulation of defence related genes. The microarray experiment, the first in lentil, conducted with a small number of genes themed on Asochyta and Pulse interactions was able to identify different components of the defence mechanism by comparing the transcriptional profiles of the susceptible and resistant genotypes. This study will thus form the basis of future experiments to elaborate and corroborate the genomics of lentils defence to A. lentis. Keywords: time course, disease state analysis
