Yang Yong, Zhou Lihui, Feng Linhao, Jiang Jianying, Huang Lichun, Liu Qing, Zhang Yadong, Zhang Changquan, Liu Qiaoquan
Key Laboratory of Crop Genomics and Molecular Breeding of Jiangsu Province, Zhongshan Biological Breeding Laboratory, Yangzhou University, Yangzhou 225009, China.
Jiangsu Key Laboratory of Crop Genetics and Physiology, Co-Innovation Center for Modern Production Technology of Grain Crops of Jiangsu Province, Yangzhou University, Yangzhou 225009, China.
Foods. 2024 May 23;13(11):1624. doi: 10.3390/foods13111624.
Amylose content (AC) stands as a pivotal determinant of rice grain quality, primarily governed by the gene (). The allelic variation within this gene, particularly the presence of the allele derived from the ancestral allele, significantly influences AC and is prevalent among soft rice varieties in southern China. Although both alleles are associated with lower AC, there remains a paucity of detailed understanding regarding the interplay between specific functional single nucleotide polymorphisms (SNPs) within these alleles and the overarching rice grain quality. To investigate this, we engineered three distinct transgenic rice lines, each harboring the , , or alleles in the background of the glutinous rice cultivar Nip(). This suite of transgenic rice lines showcased varying degrees of grain transparency inversely correlated to AC, which in turn influenced other physicochemical properties of the rice grains, such as taste value of cooked rice, gel consistency, and starch pasting properties. Additionally, analyses of gene expression and enzyme activity revealed that the functional SNPs, Ex4-53G to A and Ex5-53T to C, lead to a decline in the activity of granule-bound starch synthase I (GBSSI) without altering expression levels.
直链淀粉含量（AC）是水稻籽粒品质的关键决定因素，主要受 基因（）调控。该基因内的等位基因变异，特别是源自祖先 等位基因的 等位基因的存在，对AC有显著影响，且在中国南方的软质 水稻品种中普遍存在。尽管这两个等位基因都与较低的AC相关，但对于这些等位基因内特定功能性单核苷酸多态性（SNP）与整体水稻籽粒品质之间的相互作用，仍缺乏详细了解。为了研究这一点，我们构建了三个不同的转基因水稻株系，每个株系在糯米品种日本晴（Nip()）的背景下分别携带 、 或 等位基因。这组转基因水稻株系表现出不同程度的籽粒透明度，与AC呈负相关，进而影响水稻籽粒的其他理化性质，如米饭的味值、胶稠度和淀粉糊化特性。此外，基因表达和酶活性分析表明，功能性SNP，即Ex4 - 53G突变为A和Ex5 - 53T突变为C，导致颗粒结合淀粉合酶I（GBSSI）的活性下降，而不改变表达水平。
