miR319a targeting of CsTCP10 plays an important role in defense against gray blight disease in tea plant (Camellia sinensis)

Abstract

Gray blight disease occurs widely in major tea-producing areas and harms the leaves of tea trees, which affects the quality and yield of processed tea. According to an analysis of previous sequencing data, miR319a may be important in the resistance of tea plants to gray blight disease. In this study, based on 5'RLM-RACE, qRT-PCR, sODN, CIN and transient transformation experiments in tobacco, CsTCP10 and CsTCP4 were found to be cleaved by miR319a. qRT-PCR and northern blotting also revealed that the expression pattern of CsTCP10 in tea leaves was opposite to that of miR319a, while that of CsTCP4 displayed no similar change. Furthermore, a large amount of reactive oxygen species was found to accumulate in tea leaves in the antisense oligodeoxynucleotide experiment, while the expression of CsTCP10 was inhibited. These results suggest that CsTCP10 is a positive regulator of the resistance of tea plants to gray blight disease. Compared with the wild-type, the expression of AtTCP10 in transgenic Arabidopsis plants was downregulated. After infection with the pathogen, the transgenic plants were more severely damaged. Our results suggest that miR319a facilitates Pestalotiopsis infection by suppressing the expression of CsTCP10 in tea plants.

Keywords: CsTCP10; gray blight; miR319a; pathogenicity; tea plant.