Abstract
Gibberellin (GA) is an important phytohormone that can participate in various developmental processes of plants. The study found that application of GA(3) can induce parthenocarpy fruit and improve fruit set. However, the use of GA(3) affects endogenous hormones in fruits, thereby affecting fruit quality. This study mainly investigates the effect of exogenous GA(3) on endogenous hormones in sweet cherries. The anabolic pathways of each hormone were analyzed by metabolome and transcriptome to identify key metabolites and genes that affect endogenous hormones in response to exogenous GA(3) application. Results showed that exogenous GA(3) led to a significant increase in the content of abscisic acid (ABA) and GA and affected jasmonic acid (JA) and auxin (IAA). At the same time, the key structural genes affecting the synthesis of various hormones were preliminarily determined. Combined with transcription factor family analysis, WRKY genes were found to be more sensitive to the use of exogenous GA(3), especially the genes belonging to Group III (PaWRKY16, PaWRKY21, PaWRKY38, PaWRKY52, and PaWRKY53). These transcription factors can combine with the promoters of NCED, YUCCA, and other genes to regulate the content of endogenous hormones. These findings lay the foundation for the preliminary determination of the mechanism of GA(3)'s effect on endogenous hormones in sweet cherry and the biological function of WRKY transcription factors.