Objective  FtsH gene plays an important role in plant stress resistance. Revealing the function and expression pattern of FtsH gene in tea plant can provide a theoretical basis for the improvement of tea plant resistance to photooxidation and high temperature stress.

  Method  The FtsH gene was identified by tea plant genome data, and a CsFtsH31 gene sensitive to high temperature was screened by bioinformatics analysis. The CsFtsH31 gene was overexpressed in tobacco, and the expression patterns of CsFtsH31 gene against photooxidation and high temperature were analyzed.

  Result  A total of 45 FtsH genes were identified in the genome of tea plant, which were divided into five categories according to the evolutionary relationship. The members of this family are distributed on different chromosomes of tea plants. CsFtsH genes in tea plants are differentially expressed in different tissues and stress conditions. After high temperature treatment, CsFtsH14, CsFtsH31 and CsFtsH34 genes in tea plants showed an increasing trend over time, and CsFtsH31 is particularly sensitive to high temperature. The transgenic tobacco with CsFtsH31 gene was obtained by genetic transformation of CsFtsH31 gene. The transgenic tobacco with CsFtsH31 gene was subjected to stress treatment. The results showed that the chlorophyll and soluble sugar content and superoxide dismutase activity of transgenic tobacco were higher than wild type, while malondialdehyde was lower than wild type.

  Conclusion  The CsFtsH31 gene was expressed in tobacco by increasing the content of chlorophyll and soluble sugar, and the activity of superoxide dismutase, reducing the content of malondialdehyde, scavenging the reactive oxygen species produced by stress, protecting the function of membrane structure, and improving the resistance of tobacco to light oxidation and high temperature stress.