Sugimoto Nobuko, Forsline Philip, Beaudry Randolph
Department of Horticulture, Michigan State University , East Lansing, Michigan 48824, United States.
J Agric Food Chem. 2015 Feb 25;63(7):2106-16. doi: 10.1021/jf505523m. Epub 2015 Feb 16.
The volatile ester and alcohol profiles of ripening apple fruit from 184 germplasm lines in the USDA Malus Germplasm Repository at the New York Agricultural Experiment Station in Geneva, NY, USA, were evaluated. Cluster analysis suggested biochemical relationships exist between several ester classes. A strong linkage was revealed between 2-methylbutanoate, propanoate, and butanoate esters, suggesting the influence of the recently proposed "citramalic acid pathway" in apple fruit. Those lines with a high content of esters formed from 2-methylbutan-1-ol and 2-methylbutanoate (2MB) relative to straight-chain (SC) esters (high 2MB/SC ratio) exhibited a marked increase in isoleucine and citramalic acid during ripening, but those lines with a low content did not. Thus, the data were consistent with the existence of the hypothesized citramalic acid pathway and suggest that the Geneva Malus Germplasm Repository, appropriately used, could be helpful in expanding our understanding of mechanisms for fruit volatile synthesis and other aspects of secondary metabolism.
对美国纽约州日内瓦市纽约农业试验站美国农业部苹果种质资源库中184个种质系的成熟苹果果实的挥发性酯类和醇类成分进行了评估。聚类分析表明，几种酯类之间存在生化关系。2-甲基丁酸酯、丙酸酯和丁酸酯之间存在很强的联系，这表明最近提出的苹果果实中的“柠苹酸途径”的影响。相对于直链（SC）酯（高2-甲基丁酸/直链酯比率），那些由2-甲基丁醇和2-甲基丁酸（2MB）形成的酯含量高的品系在成熟过程中异亮氨酸和柠苹酸显著增加，但那些含量低的品系则没有。因此，数据与假设的柠苹酸途径的存在一致，并表明适当地利用日内瓦苹果种质资源库有助于扩大我们对果实挥发性物质合成机制和次生代谢其他方面的理解。
