Altered expression of the bZIP transcription factor DRINK ME affects growth and reproductive development in Arabidopsis thaliana.

Here we describe an uncharacterized gene that negatively influences Arabidopsis growth and reproductive development. DRINK ME (DKM; bZIP30) is a member of the bZIP transcription factor family, and is expressed in meristematic tissues such as the inflorescence meristem (IM), floral meristem (FM), and carpel margin meristem (CMM). Altered DKM expression affects meristematic tissues and reproductive organ development, including the gynoecium, which is the female reproductive structure and is determinant for fertility and sexual reproduction. A microarray analysis indicates that DKM overexpression affects the expression of cell cycle, cell wall, organ initiation, cell elongation, hormone homeostasis, and meristem activity genes. Furthermore, DKM can interact in yeast and in planta with proteins involved in shoot apical meristem maintenance such as WUSCHEL, KNAT1/BP, KNAT2 and JAIBA, and with proteins involved in medial tissue development in the gynoecium such as HECATE, BELL1 and NGATHA1. Taken together, our results highlight the relevance of DKM as a negative modulator of Arabidopsis growth and reproductive development.