Affiliation:
1. Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/ Zhongshan Biological Breeding Laboratory, Agricultural College of Yangzhou University
2. Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops/ Key Laboratory of Plant Functional Genomics of the Ministry of Education, Agricultural College of Yangzhou University
3. Key Laboratory of Rice Biology, China National Rice Research Institute
Abstract
As a master regulator of seed development, Leafy Cotyledon 1 (LEC1) promotes chlorophyll (Chl) biosynthesis in
Arabidopsis
, but the mechanism underlying this remains poorly understood. Here, we found that loss of function of
OsNF-YB7
, a
LEC1
homolog of rice, leads to chlorophyllous embryo, indicating that
OsNF-YB7
plays an opposite role in Chl biosynthesis in rice compared with that in
Arabidopsis
. OsNF-YB7 regulates the expression of a group of genes responsible for Chl biosynthesis and photosynthesis by directly binding to their promoters. In addition, OsNF-YB7 interacts with Golden 2-Like 1 (OsGLK1) to inhibit the transactivation activity of OsGLK1, a key regulator of Chl biosynthesis. Moreover, OsNF-YB7 can directly repress
OsGLK1
expression by recognizing its promoter
in vivo
, indicating the involvement of OsNF-YB7 in multiple regulatory layers of Chl biosynthesis in rice embryo. We propose that OsNF-YB7 functions as a transcriptional repressor to regulate Chl biosynthesis in rice embryo.
Publisher
eLife Sciences Publications, Ltd