Genome-wide identification of heat shock transcription factors and potential role in regulation of antioxidant response under hot water and glycine betaine treatments in cold-stored peaches

Background Heat shock transcription factors (Hsfs) play pivotal roles in plant response to stress. Although glycine betaine (GB) and hot water (HW) treatments are effective in reducing chilling injury (CI), little is known about characterization of Hsfs gene family and their potential roles in alleviating CI by regulating antioxidant system in peach fruit. Results In this study, 17 PpHsfs were identified in peach genome and investigated by using bioinformatics, including chromosomal locations, phylogenetic relationships, gene structure, motifs and promoter analyses. Furthermore, the expression patterns of PpHsfs under GB and HW treatments were investigated. PpHsfs showed different expression patterns in GB- and HW-treated fruit, while most of them were significantly up-regulated by both treatments, especially PpHsfA1a/b, PpHsfA2a, PpHsfA9a and PpHsfB2a/b. Meanwhile, GB and HW treatments induced the higher levels of genes expressions and antioxidant enzymes activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) compared to control, contributing to inhibiting hydrogen peroxide (H2 O2 ) accumulation and superoxide anion (O2 .- ) production. Moreover, the correlation analysis between PpHsfs and antioxidant-related genes showed that three PpAPXs were significantly correlated with ten PpHsfs, while PpCAT and PpSOD had no significant correlations with PpHsfs, which indicated that PpAPX might be regulated by PpHsfs. Conclusions Results indicated that GB and HW treatments induced different PpHsfs transcript levels to regulate the antioxidant genes expressions, which might be beneficial to inhibit the accumulation of reactive oxygen species and protect the integrity of cell structure, thus alleviating the development of CI in peach fruit during cold storage. This article is protected by copyright. All rights reserved.