Affiliation:
1. Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs, National Center for Tea Plant Improvement, Tea Research Institute Chinese Academy of Agricultural Sciences Hangzhou China
2. State Key Laboratory of Plant Environmental Resilience, College of Life Sciences Zhejiang University Hangzhou Zhejiang China
Abstract
AbstractCold stress negatively impacts the growth, development, and quality of Camellia sinensis (Cs, tea) plants. CBL‐interacting protein kinases (CIPK) comprise a pivotal protein family involved in plant development and response to multiple environmental stimuli. However, their roles and regulatory mechanisms in tea plants (Camellia sinensis (L.) O. Kuntze) remain unknown. Here we show that CsCBL‐interacting protein kinase 11 (CsCIPK11), whose transcript abundance was significantly induced at low temperatures, interacts and phosphorylates tau class glutathione S‐transferase 23 (CsGSTU23). CsGSTU23 was also a cold‐inducible gene and has significantly higher transcript abundance in cold‐resistant accessions than in cold‐susceptible accessions. CsCIPK11 phosphorylated CsGSTU23 at Ser37, enhancing its stability and enzymatic activity. Overexpression of CsCIPK11 in Arabidopsis thaliana resulted in enhanced cold tolerance under freezing conditions, while transient knockdown of CsCIPK11 expression in tea plants had the opposite effect, resulting in decreased cold tolerance and suppression of the C‐repeat‐binding transcription factor (CBF) transcriptional pathway under freezing stress. Furthermore, the transient overexpression of CsGSTU23 in tea plants increased cold tolerance. These findings demonstrate that CsCIPK11 plays a central role in the signaling pathway to cold signals and modulates antioxidant capacity by phosphorylating CsGSTU23, leading to improved cold tolerance in tea plants.