Biotechnology Bulletin ›› 2025, Vol. 41 ›› Issue (2): 210-220.doi: 10.13560/j.cnki.biotech.bull.1985.2024-0542

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Cloning and Functional Analysis of CsWAK8 Gene from Camellia sinensis during Cold Stress

JIAO Xiao-yu(), WU Qiong, LIU Dan-dan, SUN Ming-hui, RUAN Xu, WANG Lei-gang, WANG Wen-jie()   

  1. Tea Research Institute, Anhui Academy of Agricultural Sciences, Hefei 230001
  • Received:2024-06-07 Online:2025-02-26 Published:2025-02-28
  • Contact: WANG Wen-jie E-mail:670618026@qq.com;391590137@qq.com

Abstract:

Objective The wall-associated kinase (WAK) is a unique class of receptor-like kinase (RLK) that plays an important role in regulating plant growth and responding to both biotic and abiotic stresses. Exploring the function of CsWAK8 in responding to cold stress may provide a theoretical basis for further analysis of the cold resistance mechanisms in Camellia sinensis. Method The CsWAK8 gene was cloned from the leaves of C. sinensis. The quantitative real-time PCR method was used to analyze the expression pattern of the CsWAK8 gene in different tissues and different cold-resistant tea tree varieties during the wintering period. An agrobacterium-mediated method was used to heterologously express the CsWAK8 gene in Arabidopsis thaliana. The cold-treated phenotypic observation, enzyme activity determination, and cold-response-related gene expression detection of transgenic plants were also carried out. Result The CDS of CsWAK8 gene is 2 307 bp, and encodes a protein of 768 amino acids, which contained a conserved domain unique to the WAK family. CsWAK8 was highly expressed in the mature leaves of C. sinensis, and its expression in the leaves and roots of cold-sensitive tea tree varieties was significantly higher than that in cold-tolerant ones during the wintering period. Nine transgenic lines of A. thaliana were acquired through the heterologous over-expressions of the CsWAK8 gene, and three of these lines were analyzed for their cold resistances. Under cold stress, the root lengths and survival rates of the transgenic lines were significantly lower than those of the wild type. Additionally, the degree of wilting in the rosette leaves of potted seedlings was higher in the transgenic lines compared to the wild type, and the MDA content in the transgenic variety L48 was significantly higher than that of the wild type after 6 h of freezing treatment. Furthermore, qPCR analysis revealed that the relative expressions of AtCBFs in the CsWAK8 gene transgenic A. thaliana under cold treatment were significantly lower than those in the wild type. Conclusion The transgenic A. thaliana is more sensitive to cold treatment than wild-type A. thaliana. CsWAK8 may play a negative regulatory role in response and tolerance to cold stress through the CBF-mediated cold-signaling pathway.

Key words: Camellia sinensis, wall associated kinase (WAK), gene cloning, functional verification, cold stress