SnRK1 phosphorylation of FUSCA3 positively regulates embryogenesis, seed yield, and plant growth at high temperature in Arabidopsis.

ABSTRACT: The transcription factor FUSCA3 (FUS3) acts as a major regulator of seed maturation in Arabidopsis. FUS3 is phosphorylated by the SnRK1 catalytic subunit AKIN10/SnRK1α1, which belongs to a conserved eukaryotic kinase complex involved in energy homeostasis. Here we show that AKIN10 and FUS3 share overlapping expression patterns during embryogenesis, and that FUS3 is phosphorylated by AKIN10 in embryo cell extracts. To understand the role of FUS3 phosphorylation, we generated fus3-3 plants carrying FUS3 phosphorylation-null (FUS3S>A) and phosphorylation-mimic (FUS3S>D) variants. While FUS3S>A and FUS3S>D rescued all the fus3-3 seed maturation defects, FUS3S>A showed reduced transcriptional activity and enhanced fus3-3 previously uncharacterized phenotypes. FUS3S>A embryos displayed increased

SUBMITTER: Chan A 

PROVIDER: S-EPMC5853833 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature