TabHLH27 orchestrates root growth and drought tolerance to enhance water use efficiency in wheat

作者：Dongzhi Wang, Xiuxiu Zhang, Yuan Cao, Aamana Batool, Yongxin Xu, Yunzhou Qiao, Yongpeng Li, H. M. Wang, Xuelei Lin, Xiaomin Bie, Xiansheng Zhang, Ruilian Jing, Baodi Dong, Yi‐Ping Tong, Wan Teng, Xigang Liu, Jun Xiao · 发表于：Journal of Integrative Plant Biology · 年份：2024 · DOI：10.1111/jipb.13670 · 被引用次数：37 · 研究领域：Plant nutrient uptake and metabolism、Crop Yield and Soil Fertility、Rice Cultivation and Yield Improvement

ABSTRACT Cultivating high‐yield wheat under limited water resources is crucial for sustainable agriculture in semiarid regions. Amid water scarcity, plants activate drought response signaling, yet the delicate balance between drought tolerance and development remains unclear. Through genome‐wide association studies and transcriptome profiling, we identified a wheat atypical basic helix‐loop‐helix (bHLH) transcription factor (TF), TabHLH27‐A1, as a promising quantitative trait locus candidate for both relative root dry weight and spikelet number per spike in wheat. TabHLH27‐A1/B1/D1 knock‐out reduced wheat drought tolerance, yield, and water use efficiency (WUE). TabHLH27‐A1 exhibited rapid induction with polyethylene glycol (PEG) treatment, gradually declining over days. It activated stress response genes such as TaCBL8‐B1 and TaCPI2‐A1 while inhibiting root growth genes like TaSH15‐B1 and TaWRKY70‐B1 under short‐term PEG stimulus. The distinct transcriptional regulation of TabHLH27‐A1 involved diverse interacting factors such as TaABI3‐D1 and TabZIP62‐D1. Natural variations of TabHLH27‐A1 influence its transcriptional responses to drought stress, with TabHLH27‐A1 Hap‐II associated with stronger drought tolerance, larger root system, more spikelets, and higher WUE in wheat. Significantly, the excellent TabHLH27‐A1 Hap‐II was selected during the breeding process in China, and introgression of TabHLH27‐A1 Hap‐II allele improved drought tolerance and grain yield, especially unde...