509 / 2019-03-01 08:40:46

SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASES Regulate the Identity of Embryonic Stem Cells in Arabidopsis

Embryogenesis,Ground tissue stem cell,Vascular precursor,MKK4/5,YDA,SERKs

全体主题 > Development

During embryo development, the vascular precursors and the ground tissue stem cells divide to renew themselves and produce the vascular tissue, endodermal cells and cortical cells. However, the molecular mechanisms maintaining identity of these stem cells have remained largely elusive. In this study, we show that loss function of SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE (SERK) genes results in aberrant embryo development. Fewer cortical, endodermal and vascular cells are generated in the embryo of serk1 serk2 bak1 triple mutants. The first transverse division of the vascular precursors in mid-globular embryos is abnormally altered to a longitudinal division, and the ground tissue stem cells in early-heart embryos undergo a longitudinal division. The embryo defects can be partially rescued by constitutively activated YDA and MKK5. Hence, SERK-mediated signals are likely transduced via the YDA-MKK4/5 cascade to maintain the identity of the vascular precursors and the ground tissue stem cells during embryo development.