Defense gene expression in root galls induced by Nacobbus aberrans in CM334 chilli plants

Abstract

Capsicum annuum L. CM334 is susceptible to Nacobbus aberrans but highly resistant to Phytophthora capsici. Resistance to P. capsici is associated with the over-expression of various defense genes such as those encoding pathogenesis-related proteins. The transcriptional alterations of defense-related genes were determined in galls induced by N. aberrans (Na) in CM334 chili roots. Transcripts accumulation of WRKY-a, WRKY1, POX (peroxidase), PR-1 (pathogenesis-related protein 1), and EAS (5-epiaristolochene synthase) was estimated by qRT-PCR, and they were compared with those recorded in the incompatible CM334- P. capsici (Pc) interaction. The levels of all studied genes were significantly (P ≤ 0.05) lower (WRKY1, POX and PR-1) or down-regulated (WRKY-a and EAS) in the presence of N. aberrans; in contrast, in the incompatible interaction, all genes were significantly up-regulated. The alterations induced by N. aberrans could be necessary to ensure the successful completion of its life cycle in CM334 chili roots.