The transcription factor TaWRKY58 coordinates growth and drought sensitivity in wheat by repressing TaLRR and TaBCS1

https://pmc.ncbi.nlm.nih.gov/articles/PMC13132433/

Yazhou Zhang 1,2,*, Xinyao Cheng 2,*, Xinyu Yu 2, Anyu Gu 2, Xufei Zhao 2, Mei Deng 2, Guoyue Cheng 1,2, Qiang Xu 1,2, Qiantao Jiang 1,2, Yuming Wei

Abstract

Balancing growth and stress adaptation is essential for optimizing crop productivity, yet the transcriptional mechanisms underlying this trade-off in wheat remain poorly understood. Here, we identify the WRKY transcription factor TaWRKY58 as a key repressor coordinating plant architecture and drought response. Loss-of-function mutants of TaWRKY58 exhibit increased plant height and early flowering, accompanied by elevated gibberellin levels, while overexpression restores wild-type phenotypes. Under drought stress, TaWRKY58 represses soluble sugar accumulation, and its mutants show enhanced drought tolerance. Using DAP-seq, we identified genome-wide binding sites of TaWRKY58 and uncovered a W-box-like motif enriched in its target promoters. Electrophoretic mobility shift and dual-luciferase assays confirmed that TaWRKY58 directly binds to and represses two key targets: TaLRR, encoding a leucine-rich repeat protein, and TaBCS1, encoding a mitochondrial AAA⁺ ATPase. Mutants of TaLRR and TaBCS1 display dwarfism and drought hypersensitivity, respectively, mirroring aspects of the TaWRKY58 overexpression phenotype. Our data support a model in which TaWRKY58 functions as a transcriptional repressor in a coherent regulatory module that fine-tunes growth and stress adaptation by modulating signaling and energy metabolism. This mechanism offers a potential strategy for breeding wheat with optimized yield stability under fluctuating environments.