A Genome-Wide Characterization of Receptor-like Cytoplasmic Kinase IV Subfamily Members in <i>Populus deltoides</i> Identifies the Potential Role of <i>PdeCRCK6</i> in Plant Osmotic Stress Responses
Huanhuan Pan,
Zhengquan He,
Linxiu Liu,
Renyue Cai,
Hu Huang,
Xinru Xie,
Xun Cao,
Yanan Li,
Wenmin Qiu,
Zhuchou Lu,
Xiaojiao Han,
Guirong Qiao,
Renying Zhuo,
Jianjun Hu,
Jing Xu
Affiliations
Huanhuan Pan
Key Laboratory of Three Gorges Regional Plant Genetic & Germplasm Enhancement (CTGU), Biotechnology Research Center, China Three Gorges University, Yichang 443002, China
Zhengquan He
Key Laboratory of Three Gorges Regional Plant Genetic & Germplasm Enhancement (CTGU), Biotechnology Research Center, China Three Gorges University, Yichang 443002, China
Linxiu Liu
State Key Laboratory of Tree Genetic and Breeding, The Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
Renyue Cai
Tiantai Forestry Technology Promotion Station, Tiantai 317200, China
Hu Huang
State Key Laboratory of Tree Genetic and Breeding, The Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
Xinru Xie
State Key Laboratory of Tree Genetic and Breeding, The Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
Xun Cao
Key Laboratory of Three Gorges Regional Plant Genetic & Germplasm Enhancement (CTGU), Biotechnology Research Center, China Three Gorges University, Yichang 443002, China
Yanan Li
State Key Laboratory of Tree Genetic and Breeding, The Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
Wenmin Qiu
State Key Laboratory of Tree Genetic and Breeding, The Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
Zhuchou Lu
State Key Laboratory of Tree Genetic and Breeding, The Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
Xiaojiao Han
State Key Laboratory of Tree Genetic and Breeding, The Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
Guirong Qiao
State Key Laboratory of Tree Genetic and Breeding, The Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
Renying Zhuo
State Key Laboratory of Tree Genetic and Breeding, The Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
Jianjun Hu
State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
Jing Xu
State Key Laboratory of Tree Genetic and Breeding, The Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
The IV subfamily of receptor-like cytoplasmic kinase (RLCK-IV), known as calcium-binding receptor-like cytoplasmic kinases (CRCKs), plays a vital role in plant signal transduction, particularly in coordinating growth and responses to abiotic stresses. However, our comprehension of CRCK genes in Populus deltoides, a species characterized as fast-growing and pest-resistant but with drought intolerance, is limited. Here, we identify 6 members of the CRCK subfamily on a genome-wide scale in P. deltoides, denoted as PdeCRCK1–PdeCRCK6. An evolutionary and structural analysis revealed highly conserved kinase catalytic domains across all PdeCRCKs, characterized by calmodulin (CaM)-binding sites and serine (Ser)/threonine (Thr) phosphorylation sites. The cis-acting elements of promoters indicated the presence of responsive elements for plant hormones, abiotic stresses, and transcription factor binding sites, which is supported by the distinct transcriptional expression patterns of PdeCRCKs under abscisic acid (ABA), polyethylene glycol (PEG), and mannitol treatments. A transient overexpression of PdeCRCK3/5/6 in tobacco (Nicotiana benthamiana) leaves indicated their involvement in reactive oxygen species (ROS) scavenging, polyamine gene synthesis, and ABA signaling pathway modulation. Immunoprecipitation–Mass Spectrometry (IP–MS) and a yeast two-hybrid (Y2H) assay showed that PdeCRCK6 interacted with AAA-type ATPase proteins and ubiquitin, suggesting its potential function in being involved in chloroplast homeostasis and the 26S ubiquitin protease system. Taken together, these findings offer a comprehensive analysis of the RLCK-IV subfamily members in P. deltoides, especially laying a foundation for revealing the potential mechanism of PdeCRCK6 in response to osmotic stresses and accelerating the molecular design breeding of drought tolerance in poplar.
