Transcriptional profiling of indica rice cultivar IET8585 (Ajaya) infected with bacterial leaf blight pathogen (Xoo)

An indica rice cultivar IET8585 (Ajaya), resists diverse races of the Xanthomonas oryzae pv oryzae (Xoo) pathogen attack, and is often cultivated as bacterial leaf blight (blb) resistant check in India. Earlier we reported a recessive blb resistance gene mapped to the long arm of chromosome 5 in IET8585. To further understand the mechanism of recessive and durable resistance response, two indica rice genotypes namely, i) IET8585 (Ajaya), a disease resistant indica veriety from India and ii) IR24, a bacterial leaf blight disease susceptible genotype were selected for this study. We used the 22K rice Oligoarray from Agilent technologies to study the transcript profile in the leaves of the two contrasting rice genotypes under inoculated and un-inoculated conditions during seedling stage. Keywords: Bacterial leaf blight disease resistance mechanism Overall design: We used Agilent rice gene chips (G4138A) to investigate the transcript level changes in rice leaf tissues during bacterial pathogen infection. We used two contrasting rice genotypes (IET8585 (Ajaya) blb resistant IR24 blb susceptible) differing in bacterial disease response. Plants were grown growth chambers and inoculated with bacterial pathogen on 18th DAS. Leaf sampling was done in both un-inoculated and inoculated plants at 3 time points. Two replications of microarray experiments were carried out by hybridizing the resistant samples against the susceptible samples.