Abstract
Senescence is an unavoidable physiological phenomenon that accompanied with dynamic intracellular changes for organisms. Glutathione S-transferases (GSTs) are multifunctional proteins involved in diverse intracellular events, such as primary and secondary metabolism, signaling and stress metabolism and are suggested one of senescence-related genes. However, there are a few reports for senescence-specific GST activity and its function is remained unclear. In this study, we found a senescence-induced new peak of GST activity by Butyl-chromatography from senescent barley leaves. This senescence-induced GST was purified, and analyzed its internal sequence by a tryptic in-gel digestion. The GST gene was cloned from cDNA of senescent barley leaves. The obtained sequence shows this GST is classified in plant specific tau class. Tau GST is considered to involve in a signal transduction in plant hormone. Accordingly, the purified barley GST may function as a stimulator or suppressor of leaf senescence.
