S01 - Session P5 - Induction of defense responses involving accumulation of active oxygen species in Ampelopsis species inoculated with Rhizobium vitis

Authors: Hae In Lee, Zar Le Myint, Soon Young Ahn, Seung Heui Kim, Hae Keun Yun *

Active oxygen species (AOS) are one of the important factors that mediate various defense mechanisms against foreign stresses in plants, including grapevine. AOS accumulation is correlated with resistance responses against pathogen attack in grapevine. Therefore, in this study, we evaluated the defense responses related to AOS accumulation and gene expression of superoxide dismutase ( SOD ), catalase ( CAT ) and ascorbate peroxidase ( APX ) in the leaves of Ampelopsis species inoculated with Rhizobium vitis. The results revealed that there was a correlation between AOS accumulation-related responses and gene expression patterns of SOD , CAT and APX in grapevine accessions YG10075 and YG-Songni 4, which showed that the expression of these genes and enzyme activity of SOD were increased 24 hours after pathogen inoculation, while the level of hydrogen peroxide (H 2 O 2 ) content decreased due to high expression of CAT . YG10075 and YG-Songni 4 showed that AOS accumulation-related responses and related gene expression patterns were consistent. In contrast, the expression of SOD , CAT and APX , and SOD-like activity decreased, but the content of H 2 O 2 increased after inoculation in accessions YG10042 and YG10045. While expression of SOD , CAT and APX , and SOD enzyme activity increased, the level of H 2 O 2 increased after inoculation of pathogen in accessions YG10064 and YG11030. Because there is little consistency in AOS-mediated defense responses among grapevines, further studies to elucidate the roles of AOS accumulation and the expression of related genes in the defense response is required in Ampelopsis species.