title: Acyl-CoA oxidase 1 is involved in γ-decalactone release from peach (Prunus persica) fruit.
abstract: γ-Decalactone accumulation in peach mesocarp was highly correlated with ACX enzyme activity and natural PpACX1 content. Adding the purified recombinant PpACX1 induced γ-decalactone biosynthesis in cultured mesocarp discs in vitro. Previous gene expression studies have implied that acyl coenzyme A oxidase (ACX) is related to lactones synthesis, the characteristic aroma compounds of peach. Here, we analysed the correlation between γ-decalactone content and ACX enzyme activity in mesocarp of five different types of fully ripe peach varieties. Furthermore, 'Hu Jing Mi Lu' ('HJ') and 'Feng Hua Yu Lu' ('YL'), which have strong aroma among them, at four ripening stages were selected to study the role of ACX in lactone biosynthesis. The result showed that γ-decalactone was the most abundant lactone compound. γ-Decalactone accumulation was highly correlated with ACX enzyme activity. Mass spectrometry (MS) showed that PpACX1 was the most abundant PpACX protein in fully ripe mesocarp of cv. 'HJ'. To further elucidate the function of the PpACX1 protein, the PpACX1 gene was heterologously expressed in a bacterial system and characterized in vitro. MS identification gave the molecular weight of the recombinant PpACX1 as 94.44 kDa and the coverage rate of the peptide segments was 47.3%. In cultured mesocarp discs in vitro, adding the purified recombinant PpACX1 and C16-CoA substrate induced the expected γ-decalactone biosynthesis. Using a sandwich ELISA based on mixed mono- and polyclonal antibodies against recombinant PpACX1, PpACX1 content in mesocarp was found to be highly correlated with γ-decalactone accumulation in mesocarp of five fully ripe varieties and four ripening stages of 'HJ' and 'YL'. This study revealed the vital function of PpACX1 in γ-decalactone biosynthesis in peach fruit.
authors.affiliation: Key Laboratory of Horticultural Plant Growth, Development and Quality improvement, Ministry of Agriculture, Department of Horticulture, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Liping
authors.identifier: http://orcid.org/0000-0002-6702-8345
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Horticultural Plant Growth, Development and Quality improvement, Ministry of Agriculture, Department of Horticulture, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Li
authors.affiliation: Key Laboratory of Horticultural Plant Growth, Development and Quality improvement, Ministry of Agriculture, Department of Horticulture, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Gao
authors.affiliation: Key Laboratory of Horticultural Plant Growth, Development and Quality improvement, Ministry of Agriculture, Department of Horticulture, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Yujie
authors.initials: Y
authors.lastname: Qi
authors.affiliation: Key Laboratory of Horticultural Plant Growth, Development and Quality improvement, Ministry of Agriculture, Department of Horticulture, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Wanyi
authors.initials: W
authors.lastname: Fu
authors.affiliation: Key Laboratory of Horticultural Plant Growth, Development and Quality improvement, Ministry of Agriculture, Department of Horticulture, Zhejiang University, Hangzhou, 310058, China.|Forest and Fruit Tree Institute, Shanghai Academy of Agricultural Sciences, Shanghai, 201403, China.
authors.forename: Xiongwei
authors.initials: X
authors.lastname: Li
authors.affiliation: Key Laboratory of Horticultural Plant Growth, Development and Quality improvement, Ministry of Agriculture, Department of Horticulture, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Bio-Macromolecules Analysis Lab, Analysis Center of Agrobiology, Environmental Sciences of Zhejiang University, Hangzhou, 310058, China.
authors.forename: Qikang
authors.initials: Q
authors.lastname: Gao
authors.affiliation: Key Laboratory of Horticultural Plant Growth, Development and Quality improvement, Ministry of Agriculture, Department of Horticulture, Zhejiang University, Hangzhou, 310058, China. gaozhongshan@zju.edu.cn.
authors.forename: Zhongshan
authors.initials: Z
authors.lastname: Gao
authors.affiliation: Key Laboratory of Horticultural Plant Growth, Development and Quality improvement, Ministry of Agriculture, Department of Horticulture, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Huijuan
authors.initials: H
authors.lastname: Jia
mesh_terms: D042962:Acyl-CoA Oxidase / Q000235:genetics / Q000378:metabolism*; D005638:Fruit / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*; D007783:Lactones / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D000068239:Prunus persica / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*
chemical_list: D007783:Lactones; D010940:Plant Proteins; C109757:decan-4-olide; D042962:Acyl-CoA Oxidase
keywords: Acyl-CoA oxidase 1 (ACX1); Heterologous expression; Peach [Prunus persica (L.) Batsch]; Recombinant protein; Sandwich ELISA; γ-Decalactone