Abstract: To investigate the molecular mechanisms of tea plants in response to low temperature stress, this study simulated the spring chill temperature pattern, using ‘Fuding Dabaicha’ as the experimental material for transcriptome sequencing, and subjected it to varying low temperature treatments. Differentially expressed genes (DEGs) were analyzed using the GO and KEGG pathway databases for metabolic pathway enrichment analysis, which revealed that these genes were mainly enriched in plant cell wall and metabolic pathways related to photosynthesis. Subsequently, thirteen DEGs were selected for validation via real-time quantitative PCR (qPCR), confirming the consistency of the qPCR results with the transcriptome sequencing data, thereby validating the reliability of the transcriptome data. In a subsequent study, two tea cultivars, ‘Fuding Dabaicha’ and ‘Shuchazao’, were used to evaluate various physiological indices, including leaf tissue structure, the contents of various cell wall components (cellulose, hemicellulose, and pectin), chlorophyll content, and chlorophyll fluorescence parameters. The results indicate that the leaf tissue structures of both tea cultivars underwent different degrees of thickening in response to low-temperature stress. Notably, significant differences were observed in the contents of cellulose and hemicellulose between the two cultivars, whereas the pectin content change was less pronounced. Furthermore, the chlorophyll content, photochemical quenching coefficient, maximum photochemical efficiency, and relative electron transport rate all exhibited a downward trend. Conversely, the non-photochemical quenching coefficient showed an upward trend. These observations highlight the key role of changes in cell wall components, particularly hemicellulose, and changes in photosynthesis-related parameters in the tea plants’ response to low temperature.

Key words: tea plant, low-temperature stress, transcriptome, cell wall, photosynthetic characteristics