Abstract
A double-AP2 domain transcription factor WRINKLED1 (WRI1) of Arabidopsis thaliana is expressed during the mid-stage of seed development, and it plays an essential role in seed oil synthesis. WRI1 binds to AW-box conserved among the upstream region of genes involved in fatty acid synthesis in plastids, and activates their expression to facilitate the conversion of incoming sugar to oil1). Mutations in two Aw-boxes in the upstream region of PlPKβ1 abolished the expression of PlPKβ1p::GUS in not only in developing seeds but also in vegetative tissues and floral organs, suggesting that AW box-binding factors other than WRI1 are involved in the expression in tissues other than seeds. WAT1 and WAT2, closely related to WRI1, were expressed in vegetative tissues and floral organs, and activated genes involved in fatty acid synthesis in protoplasts. To clarify differential role of WRI1, WAT1, and WAT2 in the regulation of fatty acid synthesis, we characterized single, double, and triple mutants of wri1,wat1 and wat2, and introduced PlPKβ1p::GUS to these mutants. In addition, we compared effects of overexpression of WAT1, WAT2 or WRI1. 1)Maeo et al., Plant J. 60: 476 (2009)
