Cloning and molecular characterization of phospholipase D (PLD) delta gene from longan (Dimocarpus longan Lour.)

Longan (Dimocarpus longan Lour.) is a non-climacteric fruit with a short postharvest life. The regulation of phospholipase D (PLD) activity closely relates to postharvest browning and senescence of longan fruit. In this study, a novel cDNA clone of longan PLDδ (LgPLDδ) was obtained and registered in GenBank (accession No. JF791814). The deduced amino acid sequence possessed all of the three typical domains of plant PLDs, a C2 domain and two catalytic HxKxxxxD motifs. The tertiary structure of LgPLDδ was further predicted. The western blot result showed that the LgPLDδ protein was specifically recognized by PLDδ antibody. The Q-RT-PCR (real-time quantitative PCR) result showed that the level of LgPLDδ mRNA expression was higher in senescent tissues than in developing tissues, which was also high in postharvest fruit. The western-blotting result further certified the different expression of LgPLDδ. These results provided a scientific basis for further investigating the mechanism of postharvest longan fruit adapting to environmental stress.