Research advances in leaf senescence of woody plants

Deciduous trees in temperate zone display the biological phenomenon of “spring leaf-out and autumn leaf-fall” during leaf development. Autumn leaf color changes from green to yellow or red is a typical feature of leaf senescence. Leaf senescence constitutes the last stage of leaf development and is regulated by multiple environmental signals such as photoperiod and temperature, and endogenous phytohormones such as abscisic acid and ethylene. In this review, we summarize the recent progress in understanding the complexity of leaf senescence in woody plants, including the relationship between seasonal leaf senescence and vegetative and reproductive growth, the regulatory mechanisms of phytohormones in leaf senescence, and the relationship between leaf senescence and seasonal dormancy, and propose the potential research strategies for leaf senescence in deciduous trees.