The TaSDIR1 ‐ 4A ‐ TaASR4 ‐ 3D module regulates ABA ‐related drought responses in wheat seedlings

作者：Yanhong Lei, Zongzhe Wang, Liqun Li, Ling Zhou, Bingxin Wang, Birong Chen, Haodong Qi, Jinchao Chen, Jie Cao, Shimin You, Wenjing Yang, Yanzhou Xie, Liqun Li · 发表于：New Phytologist · 年份：2026 · DOI：10.1111/nph.71322 · 研究领域：Plant Stress Responses and Tolerance、Plant Molecular Biology Research、Plant nutrient uptake and metabolism

Drought is a major constraint on global wheat productivity. Although the phytohormone abscisic acid (ABA) is a well-established regulator of drought responses, its regulatory mechanisms in wheat remain unclear. Here, we identify the abscisic acid-, stress- and ripening-induced (ASR) transcription factor TaASR4-3D as a negative regulator of drought tolerance in wheat. Constitutive overexpression of TaASR4-3D increased drought sensitivity, disrupted reactive oxygen species (ROS) homeostasis and reduced stomatal closure capacity, whereas taasr4-3d mutants showed enhanced drought tolerance. RNA sequencing and biochemical assays revealed that TaNCED2-5D and TaRD17-6D are direct targets of TaASR4-3D, which represses their expression by binding to CACCG-containing motifs in their promoters. Furthermore, the RING-type E3 ubiquitin ligase TaSDIR1-4A physically interacts with TaASR4-3D and promotes its ubiquitination and 26S proteasome-mediated degradation. Collectively, these results show that TaASR4-3D negatively regulates ABA-related drought responses and affects ROS homeostasis in wheat seedlings, whereas TaSDIR1-4A interacts with TaASR4-3D and promotes its degradation. These findings provide molecular insights for future improvement of drought tolerance in wheat.