Protein changes in response to photoperiod during dormancy induction in peach leaves and flower buds

Bud dormancy in deciduous fruit trees is a key feature for the survival of winter chill but is a limiting factor for forcing cultivation in the greenhouse. Photoperiod is an important signal in dormancy induction; the quality and quantity of many genes and proteins can change and undergo a transition from active growth to dormancy. The aim of this work was to provide new insights into these changes during the early stage of dormancy. We analyzed protein changes in response to photoperiod during dormancy induction in peach (Prunus persica cv. Chunjie) leaves and flower buds. The results showed that short photoperiod could get the buds into dormant-induction period under non-low temperature conditions. However, the dormancy induction factor for long photoperiod treatment was the decreasing of the temperature. Sixty-five differentially expressed proteins were revealed, 42 of which were identified. The critical expression period of the differentially expressed proteins was mid-September in the leaves and mid-October or slightly earlier in the flower buds. Compared with that of the other identified proteins, the expression of proteins associated with stimulus responses and stress defense was higher and occurred earlier in short-photoperiod dormancy induction, whereas the expression of proteins associated with photosynthesis and growth was lower. This study is the first to identify the name, expression pattern, functional category, and biological function of various proteins in peach leaves and flower buds during photoperiod dormancy induction.