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. State Key Laboratory of Rice Biology and Breeding, 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