GBSS-BINDING PROTEIN, encoding a CBM48 domain-containing protein, affects rice quality and yield
GBSS-BINDING PROTEIN, encoding a CBM48 domain-containing protein, affects rice quality and yield
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DOI：
10.1111/jipb.12866
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发表时间：
2019-10-18
影响因子：
11.4
通讯作者：
Hu, Peisong
中科院分区：
文献类型：
--
作者：
Wang, Wei;Wei, Xiangjin;Hu, Peisong
稻米胚乳中直链淀粉的含量在很大程度上决定了稻米的蒸煮和食用品质。颗粒结合淀粉合成酶I（GBSSI）和GBSSII分别负责胚乳和叶片中直链淀粉的生物合成。在这里，我们确定了OsGBP，水稻GBSS结合蛋白，在体外和体内与GBSSI和GBSSII相互作用。osgbp突变体叶片和籽粒中总淀粉和直链淀粉含量显著低于野生型，导致粒重和品质降低。存在于OsGBP的C-末端的碳水化合物结合模块48（CBM 48）结构域对于OsGBP与淀粉的结合至关重要。在osgbp突变体中，GBSSI和GBSSII与叶片和胚乳中淀粉结合的程度显著低于野生型。我们的数据表明OsGBP通过介导GBSS蛋白与发育中的淀粉粒的结合在叶片和胚乳淀粉合成中起重要作用。OsGBP功能的阐明加深了我们对水稻淀粉生物合成的分子基础的理解，并为产量和品质的遗传改良提供了潜在的信息。
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.