A phosphorylation cascade involving ZmSnRK2.10–ZmRIPK2–ZmWRKY38 attenuates drought response by derepressing <i>ZmSUS2</i> in maize
Abstract
Drought stress severely limits crop productivity, with transcription factors (TFs) playing pivotal roles in plant adaptation. Here, we identify the maize TF ZmWRKY38 as a positive regulator of drought tolerance. CRISPR/Cas9-mediated knockout of ZmWRKY38 increased plant sensitivity to drought compared with the wild type. We demonstrate that ZmWRKY38 binds to the promoter of the sucrose synthase gene ZmSUS2 and represses its transcription. Conversely, ZmSUS2 functions as a negative regulator of drought tolerance, as zmsus2 mutants displayed enhanced drought resistance. Moreover, we identified ZmRIPK2 (RPM1-induced protein kinase 2), a plasma membrane-localized receptor-like cytoplasmic kinase that also negatively regulates drought responses. Under abscisic acid (ABA) or drought stress, ZmSnRK2.10 phosphorylates and activates ZmRIPK2, triggering its partial translocation into the nucleus. Within the nucleus, ZmRIPK2 interacts with and phosphorylates ZmWRKY38, impairing its DNA-binding capacity and thereby alleviating transcriptional repression of ZmSUS2 . Together, our results reveal a negative feedback loop in which ZmRIPK2-mediated phosphorylation of ZmWRKY38 fine-tunes the drought stress response through modulation of ZmSUS2 expression. This mechanism illustrates how ABA signaling attenuates drought responses to balance stress adaptation with normal growth.
Article Details
Journal Info
Proceedings of the National Academy of Sciences
National Academy of Sciences
Authors (14)
Tingting Wang
State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry
Aifang Ma
State Key Laboratory of Plant Environmental Resilience, Frontiers Science Center for Molecular Design Breeding, Center for Crop Functional Genomics and Molecular Breeding, College of Biological Sciences, China Agricultural University
Jinkui Cheng
Yinan Han
State Key Laboratory of Plant Environmental Resilience, Frontiers Science Center for Molecular Design Breeding, Center for Crop Functional Genomics and Molecular Breeding, College of Biological Sciences, China Agricultural University
Xuexue Chen
State Key Laboratory of Seed Innovation, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences
Tingting Fang
State Key Laboratory of Plant Environmental Resilience, Frontiers Science Center for Molecular Design Breeding, Center for Crop Functional Genomics and Molecular Breeding, College of Biological Sciences, China Agricultural University
Ziting Zhong
State Key Laboratory of Plant Environmental Resilience, Frontiers Science Center for Molecular Design Breeding, Center for Crop Functional Genomics and Molecular Breeding, College of Biological Sciences, China Agricultural University
Yuemei Zhang
Department of Endocrinology and Metabolism, Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Centre for Diabetes
Jikang Tian
State Key Laboratory of Plant Environmental Resilience, Frontiers Science Center for Molecular Design Breeding, Center for Crop Functional Genomics and Molecular Breeding, College of Biological Sciences, China Agricultural University
Han Wang
Yu Wang
Junsheng Qi
State Key Laboratory of Plant Environmental Resilience, Frontiers Science Center for Molecular Design Breeding, Center for Crop Functional Genomics and Molecular Breeding, Department of Plant Science, College of Biological Sciences, China Agricultural University
Shuhua Yang
Zhizhong Gong