Transcriptomic analysis of fruit stored under cold conditions using controlled atmosphere in Prunus persica cv. “Red Pearl”

Abstract

Cold storage (CS) can induce a physiological disorder known as chilling injury (CI) in nectarine fruits. The main symptom is mealiness that is perceived as non-juicy fruit by consumers. Postharvest treatments such as controlled atmosphere (CA; a high CO2 concentration and low O2) have been used under cold conditions to avoid this disorder. With the objective of exploring the mechanisms involved in the CA effect on mealiness prevention, we analyzed transcriptomic changes under six conditions of “Red Pearl” nectarines by RNA-Seq. Our analysis included just harvested nectarines, juicy non-stored fruits, fruits affected for CI after CS and fruits stored in a combination of CA plus CS without CI phenotype. Nectarines stored in cold conditions combined with CA treatment resulted in less mealiness; we obtained 21.6% of juice content compared with just CS fruits (7.7%; mealy flesh). RNA-Seq data analyses were carried out to study the gene expression for different conditions assayed. During ripening, we detected that nectarines exposed to CA treatment expressed a similar number of genes compared with fruits that were not exposed to cold conditions. Firm fruits have more differentially expressed genes than soft fruits, which suggest that most important changes occur during CS. On the other hand, gene ontology analysis revealed enrichment mainly in metabolic and cellular processes. Differentially expressed genes analysis showed that low O2 concentrations combined with cold conditions slows the metabolic processes more than just the cold storage, resulting mainly in the suppression of primary metabolism and cold stress response. This is a significant step toward unraveling the molecular mechanism that explains the effectiveness of CA as a tool to prevent CI development on fruits.

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

“…A). Fruits with a postharvest‐controlled atmosphere treatment that decreases mealiness (Sanhueza et al ) and from varieties with low susceptibility to mealiness (Almeida et al ) displayed higher expression levels of ACO1 during the ripening that follows cold storage, supporting the relevance of ACO1 in avoiding mealiness.…”

“…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 .…”

The effect and mechanism of ultrasonic treatment on the postharvest texture of shiitake mushrooms (Lentinula edodes)

“…Kaji et al . () found that CO 2 accumulation in packaging causes severe softening of shiitake mushrooms, as it does for peaches, apricots, bananas and other fruits, during storage (Ahmad & Thompson, ; Rebeaud et al ., ; Sanhueza et al ., ). Therefore, it is likely that the relatively low CO 2 content in the packaging of ultrasonic‐treated mushrooms also slowed the softening.…”

Secondary metabolism associated with softening of shiitake mushroom (Lentinula edodes) induced by O2 depletion and CO2 accumulation

“…As the moisture content of Figure 5 Changes in the activities of enzymes related to cell wall degradation (a, glucanase; b, chitinase; c, cellulase). Many studies have reported that high concentrations of CO 2 contribute to the softening of fruits, such as peach (Sanhueza et al, 2015), apricots (Rebeaud et al, 2015) and bananas (Ahmad & Thompson, 2015), mainly through decreased starch and the dissolution of pectin. the mushrooms in both the treatment and control groups showed no significant changes (data not shown), we hypothesised that the main cause of mushroom softening was destruction of cell wall induced by depletion of O 2 and accumulation of CO 2 .…”