Wheat kinase TaSnRK2.4 forms a functional module with phosphatase TaPP2C01 and transcription factor TaABF2 to regulate drought response
Yanyang Zhang,
Xiaoyang Hou,
Tianjiao Li,
Ziyi Wang,
Jiaqi Zhang,
Chunlin Zhang,
Xianchang Liu,
Xinxin Shi,
Wanrong Duan,
Kai Xiao
Affiliations
Yanyang Zhang
State Key Laboratory of North China Crop Improvement and Regulation, Baoding 071001, Hebei, China; College of Agronomy, Hebei Agricultural University, Baoding 071001, Hebei, China
Xiaoyang Hou
State Key Laboratory of North China Crop Improvement and Regulation, Baoding 071001, Hebei, China; College of Agronomy, Hebei Agricultural University, Baoding 071001, Hebei, China
Tianjiao Li
State Key Laboratory of North China Crop Improvement and Regulation, Baoding 071001, Hebei, China; College of Agronomy, Hebei Agricultural University, Baoding 071001, Hebei, China
Ziyi Wang
State Key Laboratory of North China Crop Improvement and Regulation, Baoding 071001, Hebei, China; College of Agronomy, Hebei Agricultural University, Baoding 071001, Hebei, China
Jiaqi Zhang
State Key Laboratory of North China Crop Improvement and Regulation, Baoding 071001, Hebei, China; College of Agronomy, Hebei Agricultural University, Baoding 071001, Hebei, China
Chunlin Zhang
State Key Laboratory of North China Crop Improvement and Regulation, Baoding 071001, Hebei, China; College of Agronomy, Hebei Agricultural University, Baoding 071001, Hebei, China
Xianchang Liu
State Key Laboratory of North China Crop Improvement and Regulation, Baoding 071001, Hebei, China; College of Agronomy, Hebei Agricultural University, Baoding 071001, Hebei, China
Xinxin Shi
State Key Laboratory of North China Crop Improvement and Regulation, Baoding 071001, Hebei, China; College of Agronomy, Hebei Agricultural University, Baoding 071001, Hebei, China
Wanrong Duan
State Key Laboratory of North China Crop Improvement and Regulation, Baoding 071001, Hebei, China; College of Agronomy, Hebei Agricultural University, Baoding 071001, Hebei, China
Kai Xiao
State Key Laboratory of North China Crop Improvement and Regulation, Baoding 071001, Hebei, China; College of Agronomy, Hebei Agricultural University, Baoding 071001, Hebei, China; Corresponding author.
SNF1-related protein kinase 2 (SnRK2) family members are essential components of the plant abscisic acid (ABA) signaling pathway initiated by osmotic stress and triggering a drought stress response. This study characterized the molecular properties of TaSnRK2.4 and its function in mediating adaptation to drought in Triticum aestivum. Transcripts of TaSnRK2.4 were upregulated upon drought and ABA signaling and associated with drought- and ABA-responsive cis-elements ABRE and DRE, and MYB and MYC binding sites in the promoter as indicated by reporter GUS protein staining and activity driven by truncations of the promoter. Yeast two-hybrid, BiFC, and Co-IP assays indicated that TaSnRK2.4 protein interacts with TaPP2C01 and an ABF transcription factor (TF) TaABF2. The results suggested that TaSnRK2.4 forms a functional TaPP2C01-TaSnRK2.4-TaABF2 module with its upstream and downstream partners. Transgene analysis revealed that TaSnRK2.4 and TaABF2 positively regulate drought tolerance whereas TaPP2C01 acts negatively by modulating stomatal movement, osmotic adjustment, reactive oxygen species (ROS) homeostasis, and root morphology. Expression analysis, yeast one-hybrid, and transcriptional activation assays indicated that several osmotic stress-responsive genes, including TaSLAC1-4, TaP5CS3, TaSOD5, TaCAT1, and TaPIN4, are regulated by TaABF2. Transgene analysis verified their functions in positively regulating stomatal movement (TaSLAC1-4), proline accumulation (TaP5CS3), SOD activity (TaSOD5), CAT activity (TaCAT1), and root morphology (TaPIN4). There were high correlations between plant biomass and yield with module transcripts in a wheat variety panel cultivated under drought conditions in the field. Our findings provide insights into understanding plant drought response underlying the SnRK2 signaling pathway in common wheat.
