Chunying Feng, Xinshuang Zhang, Ruoyu Yang, Guohao Yang, Xiaomeng Hu, Xinyu Liu, Xue Gong, Manman Li, Xiangyang Xu, Jingfu Li, Long Cui, Jingbin Jiang, Minmin Du, Huanhuan Yang
Abstract Fruit shape is a pivotal agronomic trait in tomato that significantly influences market classification and commercial value, yet the transcriptional regulation underlying its development are not fully elucidated. In this study, we identify WRKY-S as a critical regulator of fruit shape through its function in early fruit development. Expression analysis revealed that WRKY-S is highly expressed during early fruit stages. CRISPR/Cas9-mediated knockout of WRKY-S produced rounded fruits with reduced cell number along the proximal-distal axis, while overexpression resulted in irregular fruit shapes. Furthermore, WRKY-S can directly target the known fruit shape regulator gene FS8.1 to repress its expression. Notably, wrky-s mutants also exhibited increased inflorescence branching, higher fruit numbers, and improved yield without compromising fruit weight. Our findings establish WRKY-S as a novel transcriptional factor that modifies fruit shape and improves yield-related traits, providing new insights for tomato breeding.