Induced expression of defense-related genes in Arabidopsis upon infection with Phytophthora capsici.

Recognition of pathogens by plants initiates defense responses including activation of defense-related genes and production of antimicrobial compounds. Recently, we reported that Phytophthora capsici can successfully infect Arabidopsis and revealed interaction specificity among various accession-isolate combinations. We used this novel pathosystem to demonstrate that camalexin, indole glucosinolates (iGS) and salicylic acid (SA) have a role in defense against P. capsici. To further investigate the role of camalexin-, iGS- and SA-related pathways in the differential interaction between Arabidopsis and P. capsici, we monitored expression of marker genes over time during infection. In both compatible and incompatible interactions, induction of expression was detected, but in compatible interactions transcript levels of camalexin and iGS marker genes were higher.