Deciphering the genetic mechanisms of chilling requirement for bud endodormancy release in deciduous fruit trees

Bud endodormancy in deciduous fruit trees is an adaptive trait evolved by selection for the capacity to survive unfavorable environmental conditions. Deciduous trees require a certain amount of winter chill named chilling requirement (CR) to promote bud endodormancy release. In recent decades, global warming has endangered the chill accumulation in deciduous fruit trees. Developing low-CR cultivars is a practical way to neutralize the effect of climate changes on the cultivation and distribution of deciduous fruit trees. In this review, we focus on the effect of chilling accumulation on bud endodormancy release and the genetic mechanisms underlying the chilling requirement in deciduous fruit trees. Additionally, we put forth a regulatory model for bud endodormancy and provide prospective directions for future research in deciduous fruit trees.