Tobacco Salicylic Acid Glucosyltransferase Is Active toward Tuberonic Acid (12-Hydroxyjasmonic Acid) and Is Induced by Mechanical Wounding Stress

Recently we reported that rice salicylic acid (SA) glucosyltransferase (OsSGT) is active toward 12-hydroxyjasmonic acid (tuberonic acid, TA) and that OsSGT gene expression is induced by wounding stress. Here we report that tobacco SA glucosyltransferase (NtSGT), which is thought to be an ortholog of OsSGT, is also active toward TA. Although NtSGT expression is known to be induced by biotrophic stress, it was also induced by wounding stress in the same manner as OsSGT. These results indicate that this glucosyltransferase is important not only in biotrophic stress but also for wounding stress. It was found that this enzyme is dually functional, with activity both toward TA and SA.