Genome-Wide Identification of the Gene Family in Tea Plant and Functional Analysis of and hrough Ectopic Overexpression.

Pectin methylesterase inhibitor (PMEI) inhibits pectin methylesterase (PME) activity at post-translation level, which plays core roles in vegetative and reproductive processes and various stress responses of plants. However, the roles of PMEIs in tea plant are still undiscovered. Herein, a total of 51 genes were identified from tea plant genome. - transcripts were varied in different tea plant tissues and regulated by various treatments, including biotic and abiotic stresses, sugar treatments, cold acclimation and bud dormancy. Overexpression of slightly decreased cold tolerance of transgenic associated with lower electrolyte leakage, soluble sugars contents and transcripts of many cold-induced genes as compared to wild type plants. Under long-day and short-day conditions, / promoted early flowering phenotypes in transgenic along with higher expression levels of many flowering-related genes. Moreover, overexpression of / decreased PME activity, but increased sugars contents (sucrose, glucose, and fructose) in transgenic as compared with wild type plants under short-day condition. These results indicate that are widely involved in tea plant vegetative and reproductive processes, and also in various stress responses. Moreover, negatively regulated cold response, meanwhile, / promoted early flowering of transgenic via the autonomous pathway. Collectively, these results open new perspectives on the roles of PMEIs in tea plant.