Expression profile of some resistance genes in three citrus genotypes in challenging with Pseudomonas syringae pv. syringae the causal agent of blast disease

Plant diseases are the most critical limitation factors in agricultural products. Citrus bacterial blast disease caused by Pseudomonas syringae pv. syringae is one of the most common diseases in in citrus gardens except in tropical region of the world. Host plants interact to bacterial pathogenes by inducing of resistance genes. Accumulation of pathogenesis related proteins such as, chitinase, ß-1, 3 and some of the other genes like phenyl alanine ammonia lyase and transcriptional factor WRKY40 are among the defens mechanisms in challengins to pathogens. In this research, the transcript levels of PR2, PR3, PAL and WRKY40 genes were evaluated in sour orange, limequat and okitsu lines in stimulating with Pss using quantitative real time PCR technique at different time courses. After inoculation of citrus lines to Pss, total RNA were extracted from samples at different time courses. Complementary DNA were synthesized and the expression levels of mentioned genes evaluated. Result of this study showed that transcripts levels of PR2, PR3, PAL and WRKY40 genes increased faster and significantly higher in okitsu and sour orange than limequat.