Tu Bin, Zhang Tao, Liu Pin, Yang Wen, Zheng Ling, Dai Ying, Wang Hao, Lin Song, Zhang Zehua, Zheng Xiaohang, Yuan Mengting, Chen Yong, Zhu Xiaobo, Yuan Hua, Li Ting, Xiong Jiawei, Zhong Zhaohui, Chen Weilan, Ma Bingtian, Qin Peng, Wang Yuping, Li Shigui
State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Chengdu, Sichuan, China.
Rice Research Institute of Sichuan Agricultural University, Chengdu, Sichuan, China.
Plant Biotechnol J. 2025 Jan;23(1):36-50. doi: 10.1111/pbi.14475. Epub 2024 Sep 23.
It is well known that the overall quality of japonica/geng rice is superior to that of indica/xian rice varieties. However, the molecular mechanisms underlying the quality disparities between these two subspecies of rice are still largely unknown. In this study, we have pinpointed a gene homologous to SLR1, termed LCG1, exhibiting significant expression during early caryopsis development and playing a specific role in regulating rice chalkiness and taste by affecting the accumulation of grain storage components, starch granule structure and chain length distribution of amylopectin. LCG1 physically interacts with OsBP5 and indirectly influences the expression of the amylose synthesis gene Waxy (Wx) by hindering the transcriptional activity of the OsBP5/OsEBP89 complex. Notably, sequence variations in the promoter region of LCG1 result in enhanced transcription in japonica rice accessions. This leads to elevated LCG1 expression in CSSL-LCG1, thereby enhancing rice quality. Our research elucidates the molecular mechanism underlying the impact of the LCG1-OsBP5/OsEBP89-Wx regulatory pathway on rice chalkiness and taste quality, offering new genetic resources for improving the indica rice quality.
众所周知，粳稻的整体品质优于籼稻品种。然而，这两个水稻亚种之间品质差异的分子机制仍 largely unknown。在本研究中，我们确定了一个与 SLR1 同源的基因，命名为 LCG1，其在颖果发育早期表现出显著表达，并通过影响谷物贮藏成分的积累、淀粉颗粒结构和支链淀粉的链长分布，在调节水稻垩白度和口感方面发挥特定作用。LCG1 与 OsBP5 发生物理相互作用，并通过阻碍 OsBP5/OsEBP89 复合物的转录活性间接影响直链淀粉合成基因 Waxy（Wx）的表达。值得注意的是，LCG1 启动子区域的序列变异导致粳稻品种中转录增强。这导致 CSSL-LCG1 中 LCG1 表达升高，从而提高水稻品质。我们的研究阐明了 LCG1-OsBP5/OsEBP89-Wx 调控途径对水稻垩白度和口感品质影响的分子机制，为改良籼稻品质提供了新的遗传资源。
