番茄叶绿素镁脱螯合酶基因SlNYE1突变对果实成熟物质代谢的影响

A significant effect of mutation of chlorophyll Mg-dechelatase gene SlNYE1 on the material metabolism of ripening fruits in tomato

番茄果实的营养品质主要取决于其代谢物的组成和含量。果实褪绿是成熟的标志性事件。为了探究叶绿素降解代谢对果实品质性状形成的影响,对叶绿素降解关键酶基因SlNYE1/GF突变体(gf)与野生型(AC)番茄果实成熟过程中代谢物的组成和变化趋势进行了分析。利用核磁共振氢谱(1HNMR)技术对成熟期的gf和AC果实进行了检测,鉴定出了30种代谢物,包括5种有机酸、3种糖类、16种氨基酸及其衍生物和6种其它代谢物。分析结果显示,AC果实的葡萄糖和柠檬酸含量在成熟过程中逐渐增多,而gf果实的葡萄糖含量呈现下降趋势,柠檬酸的含量先增加而后有所降低;gf果实在整个成熟期苹果酸含量较低而氨基酸含量较高。研究表明,SlNYE1/GF的突变显著影响番茄果实的生理代谢及营养品质。

The nutritional quality of tomato(Solanum lycopersicum) fruits depends largely on the content and composition of their metabolites;de-greening is the characteristic symptom of ripening fruits. In order to investigate the influence of chlorophyll(Chl) breakdown on the nutritional quality of ripening tomato fruits, an analysis of the composition, content and dynamic change of metabolites in the ripening fruits of gf mutant, with a mutation in the key Chl catabolic gene of SlNYE1/GF, was carried out, in comparison with those in the ripening fruits of wild-type AC, by ~1H NMR spectroscopy. Altogether, thirty metabolites were identified including five organic acids, three sugars, sixteen amino acids and their derivatives, and six other metabolites. Further analyses showed that the contents of glucose and citric acid increased gradually in AC fruits, whereas the content of glucose decreased and the content of citric acid increased significantly at first and then decreased in gf fruits during the ripening process. The gf mutant contained more amino acids and less malic acid throughout the fruit ripening period. These results indicate that SLNYE1/GF mutation significantly affects the metabolism of tomato fruits and consequently their nutritional quality.