Differential Expression of the CBF Gene Family During Postharvest Cold Storage and Subsequent Shelf-Life of Peach Fruit

Abstract

Peach fruits are sensitive to chilling injury (CI) during postharvest cold storage and their subsequent shelf-life, which results in loss of quality and market value. Many studies have examined the development of CI, including analyses of changes in biochemical composition, enzyme activity and gene expression; however, the molecular mechanism of CI remains unresolved. Six C-repeat (CRT) / dehydration-responsive element (DRE) binding factor (CBF) genes (PpCBF1-6) were isolated and characterized in peach fruit based on their homology to CBF genes that are available in public Prunus persica genome databases. The expression patterns of these genes were analyzed in response to varying temperatures and durations of treatment. Transcription of PpCBF1/5/6 was induced at low temperatures, whereas expression of other CBF genes remained relatively constant. The results presented here indicate that treating peach fruit with a CI-delaying temperature (0 °C) resulted in a greater accumulation of PpCBF1/5/6 transcripts than that observed in fruit treated with a CI-inducing temperature (5 °C). CBF gene induction was accompanied by a decrease in CI symptoms, including a loss of firmness, flesh browning and increased electrical conductivity, throughout the experimental 21-day cold storage period. An analysis of the upstream nucleotide sequence of CBF genes showed that a cis element inducer of CBF expression 1 (ICEr1) was detected in the promoter of PpCBF1/5/6.