Research progress on the mechanism of fruit abscission regulation in fruit trees

The abscission of fruit is a crucial stage in the ontogeny of fruit trees, signifying the detachment of fruit from the tree body. This process is integral to the survival, growth, reproduction, and economic value of fruit trees. As such, analyzing the molecular mechanisms that regulate fruit abscission is important for improving fruit tree varieties and fruit quality. Fruit abscission predominantly occurs in the abscission zone, a region in which the generation and reception of abscission-stimulating signals are regulated by multiple genes. This regulatory process is the outcome of the joint action of various factors, including cellular structure, carbohydrates, cell wall metabolic enzymes, ethylene synthesis, and signal transduction pathways. The functional dynamics and interrelationships of these factors warrant further exploration. In light of this, the present paper provides a comprehensive review of the formation and structural changes of the abscission zone, concentrations of carbohydrates, ethylene, and other substances, and expression of related genes during the fruit abscission process in fruit trees. This review aims to provide novel insights into the study of the fruit abscission mechanism and to lay a theoretical foundation for the scientific regulation of fruit abscission, improvement of fruit quality, and reduction of losses in fruit tree production.