南京农业大学万建民团队宣布他们发现了OsTPS8基因的自然变异对籼稻和粳稻的垩白度和种子活力有不同的调控作用。相关论文于2025年12月15日发表在《自然—遗传学》杂志上。

在这里，课题组人员发现了一个白垩位点qPGWC-8，它编码海藻糖-6-磷酸合成酶8 (OsTPS8)，通过与OsTPS1相互作用并抑制OsTPS1抑制海藻糖-6-磷酸（Tre6P）的生物合成。OsTPS8的自然启动子变异赋予OsbHLH001的差异转录调控。OsTPS8表达升高可降低Tre6P水平，激活OsMYBS1和α-淀粉酶基因的表达，促进淀粉降解、垩白形成和种子活力提升。该功能启动子变异定义了OsTPS8^ASO和OsTPS8^IR24两个主要单倍型，其中OsTPS8^IR24在籼稻驯化过程中被优先选择。综上所述，他们的发现建立了OsbHLH001-OsTPS8-Tre6P-α-淀粉酶信号级联，该信号级联在调控籽粒垩白度和种子活力中具有双重作用，揭示了水稻外观质量与种子活力之间的分子联系。

据介绍，垩白度和种子活力是影响稻米品质和产量的主要农艺性状。这两种性状的内在关系和调控机制尚不清楚。

附：英文原文

Title: Natural variation in OsTPS8 confers differential regulation of chalkiness and seed vigor in indica and japonica rice

Author: Chen, Xiaoli, Ren, Yulong, Dong, Hui, Jiang, Xiaokang, Zheng, Xiaoming, Duan, Erchao, Teng, Xuan, Wang, Yunlong, Gu, Chuanwei, Chen, Rongbo, Wang, Qingkai, Wang, Yongfei, Zhang, Yipeng, Zhang, Rushuang, Zhang, Yunpeng, Zhao, Wenjie, Zhang, Yu, Yang, Xue, Zhou, Lei, Li, Chao, Shan, Tiaofeng, Bao, Yiqun, Tian, Yunlu, Liu, Xi, Liu, Shijia, Guo, Tao, Chen, Mingjiang, Wang, Haiyang, Wang, Yihua, Wan, Jianmin

Issue&Volume: 2025-12-15

Abstract: Chalkiness and seed vigor are major agronomic traits affecting rice grain quality and productivity, respectively. Little is known about the intrinsic relationship and the regulatory mechanisms of these two traits. Here we identified a chalkiness locus qPGWC-8, which encodes trehalose-6-phosphate synthase 8 (OsTPS8) that suppresses trehalose-6-phosphate (Tre6P) biosynthesis by interacting with and inhibiting OsTPS1. A natural promoter variation in OsTPS8 confers differential transcriptional regulation by OsbHLH001. Elevated expression of OsTPS8 reduces Tre6P levels and activates the expression of OsMYBS1 and α-amylase genes, thus promoting starch degradation, chalkiness formation and seed vigor elevation. Two major haplotypes, OsTPS8ASO and OsTPS8IR24, were defined by this functional promoter variation, with OsTPS8IR24 preferentially selected during the domestication of indica rice. Collectively, our findings establish an OsbHLH001-OsTPS8-Tre6P-α-amylase signaling cascade that has a dual role in regulating grain chalkiness and seed vigor, which reveals a molecular link between the appearance quality and seed vigor of rice.

DOI: 10.1038/s41588-025-02429-2

Source: https://www.nature.com/articles/s41588-025-02429-2