Abstract
Autophagy functions in non-selective protein degradation, amino acid recycling and senescence of plant cells. Some of autophagy-related genes (ATG) in plant appeared to be induced in response to starvation stress. To clarify reglation mechanisms of autophagy in soybean, expression profiles of ATGs and ethylene signaling in soybean were analyzed by RT-PCR and immunoblot with specific antibodies against GmATG8i and GmEin3. Soybean seedlings were incubated in nutrient-rich medium after the cotyldon was removed. Then the seedlings were subjected to starvation treatment in the presence of protease inhibitors. Starvation stress induced expression of GmATG8i, GmATG4, GmACCS and GmERF. Immnoblot showed increase of GmATG8i and GmEin3 protein levels in starvation-treated seedlings. These results suggest that reduction of amino acid recycle by protease inhibitors in addition of the starvation treatment causes up-regulation of soybean ATG expression and that activation of ethylene signaling is involved in regulation of autophagy and ATG expression.
