Proteomic Analysis of Differentially Expressed Proteins in Luffa cylindrica During Fruit Development

Abstract: The fruit development of Luffa cylindrica is accompanied by obvious morphological transitions and complex physiological and biochemical changes， which all affect the fruit postharvest life and quality. T protein expression level of three different fruit development stages (5 days after flowering， 15 days after flowering and 30 days after flowering) was determined by using isobaric tag for relative and absolute quantification-liquid chromatograph-mass spectrometer (iTRAQ-LC-MS/MS) methods， and the differentially expressed proteins were identified， then the subcellular localization， GO (gene oncology) and KEGG (kyoto encyclopedia of genes and genomes) pathway of them were analyzed. A total of 709 proteins significantly differentially expressed were detected， among them， 209 proteins were coexisting in different fruit development stages， of which 118 proteins were up-regulated and 111 were down-regulated. The results of subcellular localization showed that the differentially expressed proteins were mainly localized in the chloroplast， cytoplasm and nucleus. GO analysis founded that tetrapyrrole binding， peroxidase activity， oxidoreductase activity， heme binding and antioxidant activity were the five main molecular functions of differential proteins， and hydrogen peroxide metabolism， stress response and defense response are the three main biological processes involved in differential proteins. KEGG pathway analysis showed that the differential proteins were mainly enriched in three metabolic pathways， which were biosynthesis of secondary metabolites， sugar metabolism and DNA replication， respectively. In this study， 36 target differentially expressed proteins were screened， which might play an important role in the fruit development of Luffa cylindrica. Among them， PAL， C4H， 4-CL， COMT and CAD were the key proteins to regulate the phenolics and lignin biosynthesis in fruits. PAL， POD， PPO， CAT and APX were involved in enzymatic browning during the later development stage of fruit. SS and α-AL played an important role in sucrose accumulation and starch degradation of Luffa cylindrica fruit. The above results will help to further clarify the regulation of Luffa cylindrica fruit development， and provide theoretical support for guiding the selection and cultivation of Luffa cylindrica.

CSTR: 32200.14.cjcb.2018.11.0003