DEFENSE GENES, ENZYMATIC ACTIVITY AND CAPSIDIOL CONTENT IN CM-334 CHILLI PEPPER INOCULATED WITH Phytophthora capsici

In order to provide information about the mechanisms that restrict colonization and reproduction of Phytophthora capsici in roots of CM-334 chilli pepper resistant to the oomycete, the present study aimed I) to compare the accumulation of POX (peroxidase), GLU (beta-1,3 glucanase), PR-1 (PRI protein) and EAS (5-epi-aristolochene synthase) gene transcripts, and 2) to compare the total enzymatic activity of peroxidases and glucanases, and the total caps idol content, in roots of CM-334 pepper inoculated or not with the oomycete. In CM-334 pepper roots inoculated with P. capsici the relative levels of POX, GLU and PR-1 were significantly increased from 6h post-inoculation (hpi), and the largest increases in comparison with the non-inoculated plants (15.4, 10.1 and 8.5 times, respectively) were recorded at 48hpi. EAS increased Considerably from 6hpi (16.3 times), but in contrast to the other genes the accumulation maximum (23 times) was observed at 12hpi. The activity of glucanases and peroxidases increased as time after oomycete inoculation progressed and for both enzymes the increase was significant (P <= 0.05) at 12, 24 and 48hpi. The capsidiol content of inoculated CM-334 plants was significantly higher (P <= 0.05) with respect to non-inoculated plants, with increments of 69.7, 165.1, 259.1 and 386.7% at 6, 12, 24 and 48 hpi, respectively.