GBSS‐BINDING PROTEIN, encoding a CBM48 domain‐containing protein, affects rice quality and yield. Issue 7 (18th October 2019)

• Record Type: Journal Article
• Authors: Wang, Wei; Wei, Xiangjin; Jiao, Guiai; Chen, Wenqiang; Wu, Yawen; Sheng, Zhonghua; Hu, Shikai; Xie, Lihong; Wang, Jiayu; Tang, Shaoqing; Hu, Peisong
• Is Part Of: Journal of integrative plant biology. Volume 62:Issue 7(2020)
• Page Start: 948
• Page End: 966
• Publication Date: 2019-10-18
• Subjects: Plants -- Periodicals; Plants -- China -- Periodicals; Electronic journals; 580.5
• DOI: 10.1111/jipb.12866
• Languages: English
• ISSNs: 1672-9072

Abstract

Abstract: The percentage of amylose in the endosperm of rice ( Oryza sativa ) largely determines grain cooking and eating qualities. Granule‐bound starch synthase I (GBSSI) and GBSSII are responsible for amylose biosynthesis in the endosperm and leaf, respectively. Here, we identified OsGBP, a rice GBSS‐binding protein that interacted with GBSSI and GBSSII in vitro and in vivo . The total starch and amylose contents in osgbp mutants were significantly lower than those of wild type in leaves and grains, resulting in reduced grain weight and quality. The carbohydrate‐binding module 48 (CBM48) domain present in the C‐terminus of OsGBP is crucial for OsGBP binding to starch. In the osgbp mutant, the extent of GBSSI and GBSSII binding to starch in the leaf and endosperm was significantly lower than wild type. Our data suggest that OsGBP plays an important role in leaf and endosperm starch biosynthesis by mediating the binding of GBSS proteins to developing starch granules. This elucidation of the function of OsGBP enhances our understanding of the molecular basis of starch biosynthesis in rice and contributes information that can be potentially used for the genetic improvement of yield and grain quality. Abstract : GBSS‐BINDING PROTEIN (OsGBP), a CBM48 domain‐containing protein, interacts with GBSSs to affect the biosynthesis of amylose in rice leaf and grain. Osgbp mutants show a chalky endosperm, resulting in reduced qualityand grain weigh. Our data show that the CBM48 domain is crucial for OsGBP binding to starch.