Zhao Yongyan, Wu Hongyu, Zhao Ting, Huang Shengcai, Hao Yupeng, Chen Yidan, Feng Shouli, Wang Luyao, Zhu Yumeng, Huang Kai, Han Jin, Li Yiqian, Wang Siyuan, Dong Zeyu, Zhu Tianneng, Zhao Shengjun, Liang Yajun, Zhang Zhiyuan, Zhong Bojian, Song Hai, Zhang Tianzhen, Guan Xueying
The Advanced Seed Institute, Zhejiang Key Laboratory of Crop Germplasm Innovation and Utilization, Plant Precision Breeding Academy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 300058, China; Hainan Institute of Zhejiang University, Building 11, Yongyou Industrial Park, Yazhou Bay Science and Technology City, Yazhou District, Sanya, Hainan 572025, China.
The Advanced Seed Institute, Zhejiang Key Laboratory of Crop Germplasm Innovation and Utilization, Plant Precision Breeding Academy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 300058, China.
J Adv Res. 2025 Jul 27. doi: 10.1016/j.jare.2025.07.037.
Breeding high-yield crops has long been a fundamental goal in global agriculture, with seeds serving as the essential vehicle to achieve this aim. Therefore, understanding the regulatory mechanisms of seed size is critical for ensuring food security.
Our study focused on the natural variation, molecular regulatory mechanism and functional evolution of yield trait-related gene GhGRDP1, identified through GWAS and eQTL analyses in upland cotton natural population.
Population resequencing and phenotypic data analysis were combined with Kompetitive Allele Specific PCR, degradome, GUS staining assays, and qPCR revealed the natural variation, evolutionary history and geographic origins of GhGRDP1. Using CRISPR-Cas9 gene editing and plant transformation techniques, GRDP1 transgenic plants of cotton, rice and Arabidopsis were generated to unravel its conserved role in seed regulation. Co-IP, pull down, BiFC, LCI and enzyme activity assays were used to explore the molecular mechanism of GhGRDP1. The evolution of GRDP1 was understood through phylogenetic analysis and protein structure prediction, segmental interaction and enzyme activity assays.
A 1-bp deletion in the eighth exon of GhGRDP1 initiates the nonsense-mediated mRNA decay (NMD) mechanism, causing variations in seed index (SI) and lint percent (LP) among cotton populations. This variant, unique to Gossypium hirsutum, originated from specific races and was strongly selected during domestication. GhGRDP1 positively regulates seed size and weight without compromising fiber quality, correlating with osmolyte accumulation in ovules. GhGRDP1 interacts with UDP-L-rhamnose synthase (GhRHM1) in vivo and in vitro, functioning as an activator of GhRHM1 enzymatic activity involved in cell wall composition. Notably, GRDP1 evolved a short glycine-rich domain (sGRD) on C-terminal throughout core angiosperms, playing a conserved role in seed development across both monocots and eudicots.
These findings significantly advance understanding the genetic basis of phenotypic variation in cotton seed yield, providing valuable targets for high-yield crop breeding.
长期以来，培育高产作物一直是全球农业的一个基本目标，种子是实现这一目标的关键载体。因此，了解种子大小的调控机制对于确保粮食安全至关重要。
我们的研究聚焦于陆地棉自然群体中通过全基因组关联研究（GWAS）和表达数量性状位点（eQTL）分析鉴定出的产量性状相关基因GhGRDP1的自然变异、分子调控机制和功能进化。
将群体重测序和表型数据分析与竞争性等位基因特异性PCR、降解组、GUS染色分析以及定量PCR相结合，揭示了GhGRDP1的自然变异、进化历史和地理起源。利用CRISPR-Cas9基因编辑和植物转化技术，构建了棉花、水稻和拟南芥的GRDP1转基因植株，以阐明其在种子调控中的保守作用。通过免疫共沉淀、下拉实验、双分子荧光互补、荧光素酶互补成像和酶活性分析来探究GhGRDP1的分子机制。通过系统发育分析、蛋白质结构预测、片段相互作用和酶活性分析来了解GRDP1的进化过程。
GhGRDP1第八外显子中的一个1碱基缺失启动了无义介导的mRNA降解（NMD）机制，导致棉花群体间种子指数（SI）和皮棉百分率（LP）出现变异。这种变体是陆地棉特有的，起源于特定品种，在驯化过程中受到强烈选择。GhGRDP1在不影响纤维品质的情况下正向调控种子大小和重量，这与胚珠中渗透溶质的积累相关。GhGRDP1在体内和体外均与UDP-L-鼠李糖合酶（GhRHM1）相互作用，作为参与细胞壁组成的GhRHM1酶活性的激活剂发挥作用。值得注意的是，在整个核心被子植物中，GRDP1在其C末端进化出一个短的富含甘氨酸结构域（sGRD），在单子叶植物和双子叶植物的种子发育中发挥保守作用。
这些发现显著推进了对棉花种子产量表型变异遗传基础的理解，为高产作物育种提供了有价值的靶点。
