Rice LIKE EARLY STARVATION1 cooperates with FLOURY ENDOSPERM6 to modulate starch biosynthesis and endosperm development
Author:
Yan Haigang1ORCID, Zhang Wenwei1ORCID, Wang Yihua1ORCID, Jin Jie1ORCID, Xu Hancong1ORCID, Fu Yushuang1ORCID, Shan Zhuangzhuang1ORCID, Wang Xin2ORCID, Teng Xuan1ORCID, Li Xin1ORCID, Wang Yongxiang1ORCID, Hu Xiaoqing1ORCID, Zhang Wenxiang1ORCID, Zhu Changyuan1ORCID, Zhang Xiao1ORCID, Zhang Yu1ORCID, Wang Rongqi1ORCID, Zhang Jie1ORCID, Cai Yue1ORCID, You Xiaoman1ORCID, Chen Jie1ORCID, Ge Xinyuan1ORCID, Wang Liang1ORCID, Xu Jiahuan1ORCID, Jiang Ling13ORCID, Liu Shijia13ORCID, Lei Cailin2ORCID, Zhang Xin2ORCID, Wang Haiyang2ORCID, Ren Yulong2ORCID, Wan Jianmin123ORCID
Affiliation:
1. State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University , Nanjing 210095 , China 2. State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081 , China 3. Zhongshan Biological Breeding Laboratory, Nanjing 210095, China
Abstract
Abstract
In cereal grains, starch is synthesized by the concerted actions of multiple enzymes on the surface of starch granules within the amyloplast. However, little is known about how starch-synthesizing enzymes access starch granules, especially for amylopectin biosynthesis. Here, we show that the rice (Oryza sativa) floury endosperm9 (flo9) mutant is defective in amylopectin biosynthesis, leading to grains exhibiting a floury endosperm with a hollow core. Molecular cloning revealed that FLO9 encodes a plant-specific protein homologous to Arabidopsis (Arabidopsis thaliana) LIKE EARLY STARVATION1 (LESV). Unlike Arabidopsis LESV, which is involved in starch metabolism in leaves, OsLESV is required for starch granule initiation in the endosperm. OsLESV can directly bind to starch by its C-terminal tryptophan (Trp)-rich region. Cellular and biochemical evidence suggests that OsLESV interacts with the starch-binding protein FLO6, and loss-of-function mutations of either gene impair ISOAMYLASE1 (ISA1) targeting to starch granules. Genetically, OsLESV acts synergistically with FLO6 to regulate starch biosynthesis and endosperm development. Together, our results identify OsLESV-FLO6 as a non-enzymatic molecular module responsible for ISA1 localization on starch granules, and present a target gene for use in biotechnology to control starch content and composition in rice endosperm.
Funder
National Key Research and Development Program of China National Natural Science Foundation of China Natural Science Foundation of Jiangsu Province Jiangsu Science and Technology Development Program Central Public-Interest Scientific Institution Basal Research Fund, China
Publisher
Oxford University Press (OUP)
Subject
Cell Biology,Plant Science
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