Abstract
Tuberonic acid (TA) and tuberonic acid glucoside (TAG) have been isolated from potato (Solanum tuberosum L.) leaflets and have been shown to induce tubers. These compounds have been found in various plant species and are biosynthesized from jasmonic acid. However, the enzymes that catalyze the metabolism between TA and TAG are poorly characterizing. We have identified the TAG hydrolyzing activity in rice and the enzyme catalyzing this activity, TAG glucoside (OsTAGG), was purified. In this study, novel TAG glucosidase isozyme (OsTAGG2) was purified and enzymatic characteristics were compared with OsTAGG1. OsTAGG2 showed high identity to OsTAGG1 and showed high substrate specificity toward TAG analogs, which is common to OsTAGG1. Together, these data suggested that OsTAGG2 is a novel TAG hydrolyzing glucosidase in rice. To elucidate the physiological functions of OsTAGG1 and OsTAGG2, expression analysis of these genes under stress conditions such as wounding is under way.
