Transcriptomic and metabolic analyses provide new insights into chilling injury in peach fruit

Abstract

Low temperature conditioning (LTC) alleviates peach fruit chilling injury but the underlying molecular basis is poorly understood. Here, changes in transcriptome, ethylene production, flesh softening, internal browning and membrane lipids were compared in fruit maintained in constant 0 °C and LTC (pre-storage at 8 °C for 5 d before storage at 0 °C). Low temperature conditioning resulted in a higher rate of ethylene production and a more rapid flesh softening as a result of higher expression of ethylene biosynthetic genes and a series of cell wall hydrolases. Reduced internal browning of fruit was observed in LTC, with lower transcript levels of polyphenol oxidase and peroxidase, but higher lipoxygenase. Low temperature conditioning fruit also showed enhanced fatty acid content, increased desaturation, higher levels of phospholipids and a preferential biosynthesis of glucosylceramide. Genes encoding cell wall hydrolases and lipid metabolism enzymes were coexpressed with differentially expressed ethylene response factors (ERFs) and contained ERF binding elements in their promoters. In conclusion, LTC is a special case of cold acclimation which increases ethylene production and, operating through ERFs, promotes both softening and changes in lipid composition and desaturation, which may modulate membrane stability, reducing browning and contributing to alleviation of peach fruit chilling injury.

A Prunus persica genome‐wide RNA‐seq approach uncovers major differences in the transcriptome among chilling injury sensitive and non‐sensitive varieties

“…EIL3 induction under cold storage in SE late varieties was also shown in the chilling sensitive variety Hujingmilu (Wang et al ). EIL3 is located on a ‘harvest date’ QTL (Wang et al ), becoming a good candidate to link harvesting time with susceptibility to chilling injury. EIN3/EIL1 target secondary response factors (ERFs) which, in turn, regulate genes underlying ripening‐related traits.…”

“…Ethylene biosynthesis, transduction and signaling are affected by cold storage (Fig. A, B; Tanou et al , Wang et al ). Most of the genes involved in these processes displayed a variety‐specific expression pattern.…”

“…Transcription factors (TFs), agronomic traits‐related QTLs and sensitive/resistant to chilling varieties have been characterized (Bianchi et al , Nuñez‐Lillo et al ), making P. persica an excellent model to understand chilling injury in plants. RNA‐seq technology ability to detect large number of expressed genes have been successfully used to unfold key molecular processes related to chilling injury in P. persica (Sanhueza et al , Wang et al ), tomato (Chen et al , Cruz‐Mendívil et al ), tea (Zheng et al ), tobacco (Hu et al ) and rice (Shen et al ). In this work, we selected four varieties with contrasting mealiness sensitivity, spanning early and late season varieties, and performed a genome‐wide RNA‐seq analysis to uncover the main mechanisms related to chilling injury in P. persica .…”

Effect of Ethylene on Cell Wall and Lipid Metabolism during Alleviation of Postharvest Chilling Injury in Peach

“…Peach can develop chilling injury (CI) during cold storage or after transfer to the shelf when the fruit were stored for long periods [1,2]. The most common symptoms of CI in peach are internal browning (IB) of flesh and impairment of softening [3].…”

Effects of low‐temperature conditioning and cold storage on development of chilling injuries and the transcriptome of ‘Wonderful’ pomegranate fruit

“…This process of exposing fruit to moderate temperatures before cold storage is also termed 'cold acclimation' or 'conditioning' (Hatton, 1990;Wang, 1993). It was recently shown that LTC treatments prior to cold storage alleviated peel browning in 'Huangguan' and 'Nanguo' pears and reduced CI symptoms in stored mango fruit (Li et al, 2017a;Wang et al, 2017b;Zhang et al, 2017).…”