Affiliation:
1. Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology Zhejiang University Hangzhou Zhejiang China
2. Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology Zhejiang University Hangzhou Zhejiang China
3. State Key Laboratory of Rice Biology and Breeding, Institute of Biotechnology Zhejiang University Hangzhou Zhejiang China
4. State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro‐products, Institute of Plant Protection and Microbiology Zhejiang Academy of Agricultural Sciences Hangzhou China
Abstract
AbstractReceptor‐like cytoplasmic kinases (RLCKs) represent a distinct class of receptor‐like kinases crucial for various aspects of plant biology, including growth, development, and stress responses. This study delves into the characterization of RLCK VII‐8 members within cucurbits, particularly in melon, examining both structural features and the phylogenetic relationships of these genes/proteins. The investigation extends to their potential involvement in disease resistance by employing ectopic overexpression in Arabidopsis. The promoters of CmRLCK VII‐8 genes harbor multiple phytohormone‐ and stress‐responsive cis‐acting elements, with the majority (excluding CmRLCK39) displaying upregulated expression in response to defense hormones and fungal infection. Subcellular localization studies reveal that CmRLCK VII‐8 proteins predominantly reside on the plasma membrane, with CmRLCK29 and CmRLCK30 exhibiting additional nuclear distribution. Notably, Arabidopsis plants overexpressing CmRLCK30 manifest dwarfing and delayed flowering phenotypes. Overexpression of CmRLCK27, CmRLCK30, and CmRLCK34 in Arabidopsis imparts enhanced resistance against Botrytis cinerea and Pseudomonas syringae pv. tomato DC3000, concomitant with the strengthened expression of defense genes and reactive oxygen species accumulation. The CmRLCK VII‐8 members actively participate in chitin‐ and flg22‐triggered immune responses. Furthermore, CmRLCK30 interacts with CmMAPKKK1 and CmARFGAP, adding a layer of complexity to the regulatory network. In summary, this functional characterization underscores the regulatory roles of CmRLCK27, CmRLCK30, and CmRLCK34 in immune responses by influencing pathogen‐induced defense gene expression and ROS accumulation.