Identification and Expression Analysis of ETR Gene Family in Camellia sinensis

  Objective  CsETRs were identified and analyzed to predict the potential molecular functions involving the mechanism of ethylene receptor in response to stress in tea plants.

  Method  Bioinformatics was used to identify members in the ETR family and predict their potential molecular functions. Real-time fluorescence quantitative analysis was employed for the expressions of the genes under stresses.

  Result  Six ETRs were identified from the genome of tea plants. They all consisted of N-terminal transmembrane region, GAF region, and histidine (His) kinase domain. Phylogenetic tree analysis divided them into two groups. Each member of the ETR family contained 1-12 exons. Significantly differentiated in tissues, the expressions of ETRs were high in the fruits and stems. The fluorescence quantitative expressions of the 6 genes, especially ERS1-1, were upregulated to varying degrees when exposed to low temperature. Under the stress of plant growth regulators ABA, JA, or GA, most of the genes were upregulated, especially ERS1-3, but ETR2-2 downregulated slowly when treated by ABA.

  Conclusion  On tea plants, 6 CsETRs in the family were identified with their potential molecular functions predicted and analyzed in this study. CsETRs were highly expressed in the fruits and stems that could be induced by low-temperature stress. Whereas ABA, MeJA, or GA could significantly upregulate the expression of ERS1-3.