Analysis of Evolutionary Expression Relationships of Tea Plant Genes Based on the Identification of RCI2 Gene Members in Tea Plant (Camellia sinensis)

Abstract

Plants in nature frequently encounter abiotic stresses, leading to constant mutation and evolution of plant genes as part of the adaptation process. Rare cold-inducible (RCI2) genes are a specific class of genes closely associated with abiotic stress. In our study, we identified 11 RCI2 genes in tea plants. Our evolutionary analysis revealed a high similarity between CsRCI2A and CsRCI2B with AtRCI2A and AtRCI2B. Furthermore, we found that CsRCI2B, CsRCI2D, CsRCI2I, and CsRCI2J were expressed in both drought and low-temperature conditions, as well as in different tissues. The transcript abundance of these genes varied significantly across different treatment times and tissues. However, these genes had fewer mutation sites, indicating that they underwent amino acid mutations during the evolutionary process after abiotic stress, while maintaining a stable gene structure without excessive mutation sites. Our results suggest that most of the genes in tea plants may degrade under the influence of the external environment. However, core genes, which do not undergo detrimental mutations, play a crucial role in tea plants after experiencing abiotic stress. This confirms that RCI2 genes in tea plants selectively undergo deleterious and beneficial mutations in response to abiotic stress, ultimately impacting gene expression.