Dynamic regulation of Arabidopsis β-AMYLASE1 by glutathione and thioredoxins affects starch in guard cells.

ABSTRACT: Guard cells control the opening and closure of stomatal pores in response to internal and external stimuli, ensuring gas exchange in plants. In Arabidopsis (Arabidopsis thaliana), β-AMYLASE1 (BAM1), assisted by α-AMYLASE3, begins degrading starch at dawn in guard cells to promote stomatal opening. Both enzymes are controlled by reversible disulfide bond formation, which decreases their activity. In the present study, we investigated the sensitivity of BAM1 to other redox-dependent post-translational modifications (PTM) both in vitro and in vivo. In vitro, H2O2 reversibly inactivates BAM1 and, in the presence of glutathione (GSH), induces S-glutathionylation of BAM1. Glutathionylated BAM1 is active and transiently protected from H2O2 inhibition. However, the glutathionylated state of BAM1 h

SUBMITTER: Gurrieri L 

PROVIDER: S-EPMC12351283 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature