Isolation and characterization of 9-lipoxygenase and epoxide hydrolase 2 genes: Insight into lactone biosynthesis in mango fruit (Mangifera indica L.)
Isolation and characterization of 9-lipoxygenase and epoxide hydrolase 2 genes: Insight into lactone biosynthesis in mango fruit (Mangifera indica L.)
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DOI：
10.1016/j.phytochem.2017.03.002
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发表时间：
2017-06-01
期刊：
影响因子：
3.8
通讯作者：
Gupta, Vidya S.
中科院分区：
文献类型：
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作者：
Deshpande, Ashish B.;Chidley, Hemangi G.;Gupta, Vidya S.
不同品种芒果风味的独特性和多样性是众所周知的。在各种风味代谢物中，内酯由于其成熟的特殊外观和较低的气味检测阈值，在某些芒果品种中形成了一类重要的香气挥发物。尽管内酯具有重要的生物学和生化意义，但植物内酯的生物合成途径尚不明确。本研究对高、低、无内酯含量的Alphonso、Paid和Kent品种果实中9-脂氧合酶（Mi9LOX）、环氧化物水解酶2 （MiEH2）、过氧酶、氢过氧化物裂解酶和酰基辅酶a氧化酶基因进行了实时定量分析，并解释了其内酯含量的变化规律。研究还包括芒果果实中Mi9LOX和MiEH2基因的分离、重组蛋白鉴定和瞬时过表达。重组Mi9LOX利用亚油酸和亚麻酸，而MiEH2分别利用芳香和脂肪酸环氧化物作为底物，描述了它们在脂肪酸代谢中的作用。Mi9LOX过表达后δ -戊内酯和γ -去内酯浓度显著升高，MiEH2过表达后δ -戊内酯、γ -六内酯和δ -六内酯浓度显著升高，进一步表明这些基因可能参与芒果内酯的生物合成。(C) 2017 Elsevier Ltd.版权所有。
Uniqueness and diversity of mango flavour across various cultivars are well known. Among various flavour metabolites lactones form an important class of aroma volatiles in certain mango varieties due to their ripening specific appearance and lower odour detection threshold. In spite of their biological and biochemical importance, lactone biosynthetic pathway in plants remains elusive. Present study encompasses quantitative real-time analysis of 9-lipoxygenase (Mi9LOX), epoxide hydrolase 2 (MiEH2), peroxygenase, hydroperoxide lyase and acyl-CoA-oxidase genes during various developmental and ripening stages in fruit of Alphonso, Paid and Kent cultivars with high, low and no lactone content and explains their variable lactone content. Study also covers isolation, recombinant protein characterization and transient over-expression of Mi9LOX and MiEH2 genes in mango fruits. Recombinant Mi9LOX utilized linoleic and linolenic acids, while MiEH2 utilized aromatic and fatty acid epoxides as their respective substrates depicting their role in fatty acid metabolism. Significant increase in concentration of delta-valerolactone and gamma-decalactone upon Mi9LOX over-expression and that of delta-valerolactone, gamma-hexalactone and delta-hexalactone upon MiEH2 over-expression further suggested probable involvement of these genes in lactone biosynthesis in mango. (C) 2017 Elsevier Ltd. All rights reserved.