Tomato WRKY-S transcription factor targets FS8.1 to regulate fruit shape and associated yield traits
TL;DR
expression analysis revealed that WRKY-S is highly expressed during early fruit stages, and 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.
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.