Trehalose-6-phosphate synthase gene CsTPS11 enhances cold hardiness in tea plants via modulating trehalose metabolism and CBF signaling pathway

Cold stress critically limits the sustainability of the tea industry by reducing spring tea yield and quality and restricting plant distribution. However, the metabolic basis and molecular regulatory pathways responsible for cold tolerance in tea plants have not been fully clarified. In the current study, we elucidated the pivotal function of trehalose in enhancing cold hardiness in tea plants using quasi-targeted metabolomic analyses and exogenous spraying experiments. Notably, we successfully identified 10 CsTPS genes encoding trehalose-6-phosphate synthase in tea plants. Phylogenetic analysis showed these CsTPSs were categorized into two distinct groups: Class I ( CsTPS1 – CsTPS2 ) and Class II ( CsTPS4 – CsTPS11 ). The promoters of CsTPSs contained multiple regulatory elements involved in phytohormone signaling, light response, and abiotic stress adaptation. Tea Class II TPS genes, including CsTPS6 , 7 , 9 , 10 , and 11 , exhibited high transcript levels in sink tissues, such as roots, flowers, and fruits, and their expression was upregulated under cold stress. Subcellular localization analysis revealed that CsTPS6, 7, 9, 10, and 11 were primarily localized to the cell membrane, cytoplasm, and endoplasmic reticulum. Importantly, CsTPS11 silencing increased sensitivity to freezing stress and suppressed the transcription of CsCBF - CsCOR genes in tea leaves. In contrast, CsTPS11 overexpression upregulated trehalose content in tea leaves, enhanced cold tolerance, and upregulated CsCBF - CsCOR genes. In conclusion, our research proves that trehalose functions as a protective metabolite in enhancing tea plant cold hardiness, and identifies CsTPS11 as a key target gene for improving cold resistance.