EXPRESSION OF GENES RELATED TO PATHOGENESIS IN CHILI PEPPER (Capsicum annuum L.) INOCULATED WITH Bacillus subtilis AND Meloidogyne enterolobii

Chili (Capsicum annuum L.) cultivation is remarkable for the high agro-nutritional value of the product, coupled with its commercial value. The nematodes Meloidogyne incognita and M. enterolobii (Me) affect the crop; M. enterolobii (Me) is the most relevant for its bold aggressiveness. To control these phytoparasites with ecological alternatives is of interest. The objectives of this research were to know the effect of Bacillus subtilis (Bs) (CH90) on the expression of the PR-1, PR-5, and PR-12 genes that encode proteins related to pathogenesis in chili cv. California Wonder (Cw) infected with Me; and evaluate the effect of Bs on galls (A) and egg (H) production by the nematode in Cw roots. Two independent experiments (E1 and E2) were established with a completely randomized design. In E1 and E2 the treatments were: Cw inoculated only with Me (CwMe), Cw with Bs and Me (CwBsMe), Cw only with Bs (CwBs), and Cw without inoculation (Cw). In both experiments, the inoculum level for Bs was 10⁸ UFC mL^-1, and for Me it was 500 J₂ per plant. In E1, the gene expression was determined at 3, 7, and 14 d after inoculation (DPI) with Me. In E2, variables A and H were evaluated 45 DPI with Me. PR-1 and PR-5 were overexpressed 3 and 7 DPI in the CwBsMe and CwBs treatments, in contrast with CwMe (p<0.05). At 14 DPI, the genes in all treatments had a lower expression (p<0.05). The maximum overexpression of PR-12 was recorded at 14 DPI in the CwBsMe and CwBs treatments (p<0.05). Plants of cv. C. Wonder treated with B. subtilis CH90 alone or in combination with M. enterolobii activated the defense pathways dependent on salicylic (AS) and jasmonic (AJ) acids; however, this activation did not affect the reproduction of the nematode in chili roots.