关键词: 桃, 溶质, 硬质, 果实成熟, 多肽组学

Abstract: 【Objective】To explore the differences between melting flesh and stony hard peaches at the peptide level and precursor protein level during fruit ripening. The study provides a theoretical basis for mining the key peptides that determine or regulate the ripening process.【Method】 The characteristics of peptides and precursor protein functions in ‘CN13’ (melting flesh, MF) and ‘CN16’ (stony hard, SH) peaches were analyzed by peptidome, the relative contents of precursor proteins and peptides during MF and SH peach fruit ripening were compared, and the precursor proteins of different peptide segments.was analyzed by function enrichment.【Result】In this study, the peptides of ‘CN13’ and ‘CN16’ (S3 and S4III) were extracted for mass spectrometry. A total of 473 precursor proteins were identified, including 2580 specific peptide sequences. The molecular weight, isoelectric point and cleavage sites of the peptide were summarized. In addition, the high-abundance precursor proteins corresponding to endogenous peptides were explored by COG function annotations and pathway enrichment analysis. The results showed that the precursor proteins were mainly involved in the processes of general function prediction, post-translational modification, protein turnover, energy production and conversion, carbohydrate transport and metabolism. The enrichment analysis showed that the differential peptide precursor proteins of ‘CN13’ were related to biological processes such as oxidation reduction, oxygen and oxygen and electron transport chain, and were mainly involved in glycolysis/gluconeogenesis, pentose phosphate pathway and RNA transport; The differential peptide precursor proteins in ‘CN16’ were related to biological processes such as response to metal ion, response to inorganic substance, response to cadmium ion, and were mainly involved in microbial metabolism in diverse environments, spliceosome and RNA transport; The differential peptide precursor proteins at the same stage in ‘CN13’ and ‘CN16’ at S4III were related to gene expression, translation and cellular macromolecular biological processes, and were mainly involved in RNA degradation, RNA transport and splicing.【Conclusion】There are significant differences in peptides between ‘CN13’ and ‘CN16’ during fruit ripening. The precursor proteins of differential peptide are involved in starch / sucrose metabolism, glycolysis and ribosome synthesis, it is suggested that these metabolic pathways are closely related to peach fruit ripening, which provides a theoretical reference for further exploring the key peptides which regulating peach fruit ripening and senescence..

Key words: peach, melting flesh, stony hard, fruit ripening, peptidomics