Hongxia Liu, Tian Li, Jian Hou, Xiaotong Yin, Yuquan Wang, Xuemei Si, Shoaib Ur Rehman, Lei Zhuang, Weilong Guo, Chenyang Hao, Xueyong Zhang

Plant Biotechnology Journal; 2025; IF:11.2 

DOI: 10.1111/pbi.70015

Abstract

Plant-specific WUSCHEL-related homeobox ( Wox ) transcription factors (TFs) are crucial for plant growth and development. However, the molecular mechanism of Wox -mediated regulation of thousand kernel weight (TKW) in crops remains elusive. In this research, we identified a major TKW-associated quantitative trait locus (QTL) on wheat chromosome 5DS by performing a genome-wide association study (GWAS) of a Chinese wheat mini core collection (MCC) in four environments combined by bulked-segregant analysis (BSA) and bulked segregant RNA-sequencing (BSR-seq) of wheat grains exhibiting a wide range of TKWs. The candidate TaWUS-like-5D was highly expressed in developing grains and was found to strongly negative influence grain TKW and wheat yield. Meanwhile, the RNAi lines, CRISPR/Cas9-edited single and double knockout mutants (AABB dd and AA bbdd ), as well as the stop-gained aa BB Kronos mutants, exhibited a significant increase in grain size and TKW ( P < 0.05 or P < 0.01) and a 10.0% increase in yield ( P < 0.01). Further analyses indicated that TaWUS-like-5D regulates TKW by inhibiting the transcription of sucrose, hormone and trehalose metabolism-related genes, subsequently sharply decreasing starch synthesis in wheat grains. The results of this study provide a fundamental molecular basis for further elucidating the mechanism of Wox -mediated regulation of grain development in crops.