Transcriptome and genome analysis to identify C2H2 genes participated in Low temperature conditioning-alleviated postharvest chilling injury of peach fruit

Abstract Objectives The work intended to identify candidate C2H2 genes participated in Low-temperature conditioning (LTC) -alleviated postharvest chilling injury of peach fruit. Materials and Methods For LTC treatment, fruit were pre-stored at 10 oC for 5 d, and then transferred to 0 oC storage. Fruit firmness was measured by the hardness tester. H2O2 content was determined by luminosity measurement model using the multifunctional enzyme labeler. Identification of C2H2 family members was performed by HMMSCAN according to peach genome. Cis-acting element of gene promoters was analyzed using the Plant CARE website. WGCNA analysis was performed by WGCNA package in BMK Cloud platform. Results LTC treatment decreased flesh browning rate and H2O2 production of ‘Beijing No.9’ peach. Transcription factors identification of DEGs in 0 oC and LTC treatment indicated peach C2H2 participated the regulation of chilling injury. A total of 47 C2H2 genes were identified based on peach genome. qRT-PCR, phylogenetic analysis and promoter cis-acting element analysis revealed ZFP21 was involved in the regulation of LTC-alleviated chilling injury in peach. Weighted gene co-expression network analysis and dual luciferase assay suggested ZFP21 participated in LTC-alleviated chilling injury by down-regulating the expression of ROS-related genes Rboh. Conclusions Our investigation, based on genome and RNA-seq, unveiled that ZFP21 was involved in LTC treatment-alleviated chilling injury of peach fruit. This work is useful for the identification of peach cold tolerance-related genes and the study of C2H2 family in peach.