Genome-wide Identification Of PpPLD Gene Family And Its Function Analysis Of Response To Low Temperature Acclimation Of Postharvest Peach

Peach which is cold-sensitive fruits is easily suffered from chilling injuryduring cold storage. Phospholipase D involves in plant response to low temperatureadaptability, but the specific molecular mechanism of regulation is unclear. In thispaper, based on genome-wide identification of PpPLD gene family, chilling injuryindicators of postharvest peach fruit during cold storage were analyzed to study thepeach fruit chilling injury law. Combined with n-butanol, salicylic acid,1-MCP andheat treatment, the function of phospholipase D regulation peach fruit coldadaptation was carried out. The main results are as follows:(1)11phospholipase D genes were identified from genome database of peachthrough bioinformatics tools, which can be divided into six subfamilies, β,,, ζ and φ. The family contains three phospholipase D, two phospholipase Dβ,two phospholipase D, one phospholipase D, two phospholipase Dζ and onephospholipase Dφ. Meanwhile, gene structures, amino acid domains, genedistribution in the chromosome and other parts of the PpPLD family were analyzed.(2) Peach fruit chilling injury indexes of different treatments were analyzed, whichindicates that groups of browning index, decay index, relative conductivity andMDA content showed an upward trend, but the indicators were lower than thecontrol group.1-MCP, salicylic acid, n-butanol and heat treatment inhibitedcold damage occurring on different degrees. The effect of1-MCP inhibit wasthe best, heat treatment had worst inhibitory effect, and salicylic acid andn-butanol had the same inhibitory effect.(3) Quantitative PCR was used to study11PpPLD mRNA expression level in thetranscription level. In the early storage, PpPLD mRNA relative expression ofCK group was rising in varying degrees, salicylic acid and n-butanol treatmentgroup had decreased relative expression level. But PpPLDɑ1、PpPLDɑ2、 PpPLD、PpPLDβ2and PpPLDζ1of1-MCP treatment group had decreasedrelative expression level, PpPLDɑ3、PpPLDβ1、PpPLD1、PpPLD2、PpPLDζ2and PpPLDφ mRNA relative expression were rising. PpPLD1、PpPLD3、PpPLDβ1、PpPLDβ2、PpPLD1and PpPLDφ of heat treatmentgroup had rising relative expression level, PpPLDɑ2、PpPLD2and PpPLDζ1were decreased. In the latter part of the storage, PpPLD1、PpPLD3、PpPLDβ2、PpPLD1、PpPLD2and PpPLDφ exhibited a rising trend, whichmay be related to the degradation of the cell membrane.