Deciphering transcriptional changes in susceptible rice plants infected by Magnaporthe grisea

International audienc

Exploiting transcript profiling data to decipher rice – Magnaporthe grisea compatibility mechanisms

International audienceWhereas the molecular events associated with disease resistance are largely studied, those occurring in susceptible plants are poorly known, especially in Monocots. We chose the rice/Magnaporthe grisea system to explore the molecular modifications that are induced in susceptible plant tissues following pathogen attack. A truly compatible interaction (between O. sativa cultivar Nipponbare and M. grisea isolate FR13) at time points where infection occurs without visible symptoms was studied. Changes in rice transcript levels at 3 and 4 days post inoculation were measured using Affymetrix chips. In addition to the up-regulation of a large number of defence-related genes, this analysis revealed new features indicating extensive reprogramming of host gene expression. Microarray expression data were confirmed for 35/38 genes using quantitative RT-PCR, thus demonstrating the robustness of these transcript profiling experiments. This comprehensive survey of global gene expression in response to colonization by a virulent fungal isolate constitutes an important resource that should help us to further our understanding of the rice blast disease process