【摘要】 为了明确导致薄皮甜瓜果实香味差异的酯类物质及其关键酶活性和基因的相关性，以薄皮甜瓜DX108和DX3-5果实为试验材料，研究了果实酯类代谢物的差异及羧酸酯酶(CXE)和醇酰基转移酶(AAT)活性和基因表达特性。结果表明:薄皮甜瓜果实中共检测到644种代谢物，其中酯类物质114种;成熟果实中共检测到差异代谢物108种，差异的酯类物质23种;与DX3-5相比，DX108成熟果实中酯类物质种类与含量增加明显，表明酯类物质是薄皮甜瓜成熟果实香气形成差异的关键物质; K-均值聚类分析法发现乙酸异戊酯、乙酸2-甲基丁酯、β-苯乙酸乙酯、乙酸对甲酚酯、乙酸己酯、苯乙酸甲酯、邻氨基苯甲酸甲酯和己酸乙酯是造成2个薄皮甜瓜品种成熟果实香味差异的关键酯类物质。此外，果实AAT和CXE活性变化趋势相反，暗示了AAT和CXE协调影响了酯类物质的代谢;随着果实的发育，AAT和CXE基因家族成员的表达特性存在差异，且相关性分析暗示了CmCXE5、CmCXE6和Cm AAT5参与了薄皮甜瓜成熟果实中8种差异酯类物质的代谢。由上可知，8种关键酯类物质合成与积累差异是导致2种薄皮甜瓜成熟果实香味差异的重要原因，且CmCXE5、CmCXE6和Cm AAT5可能发挥了主要调节作用。更多还原

【Abstract】 To determine the relationship between the esters compounds and key enzyme activities and genes that involved in the differences in aromas of oriental melon fruits,the disparities of ester metabolites and the enzyme activities and gene expression characteristics of CXE and AAT were investigated,with the fruits of oriental melon,DX108 and DX3-5,used as experimental materials. The results showed that a total of 644 metabolites were detected in oriental melon fruits,including 114 esters. A total of 108 metabolite variations and 23 different esters were detected in mature fruits. Compared with DX3-5,the types and contents of esters in ripe fruits of DX108 increased significantly,indicating that esters were the key substances in the formation of aroma difference in ripe fruits of oriental melons. K-means clustering analysis showed that isoamyl acetate,ethyl 2-methybuyrate,β-ethyl phenylacetate,pcresol acetate,hexyl acetate ester,methyl phenylacetate,methyl anthranilate and ethyl caproate were the key esters,which caused the difference of ripe fruit aroma between two oriental melons. In addition,the activities of AAT and CXE in fruits showed opposite trend,suggesting that the coordination of AAT and CXE affected the metabolism of esters. The expression characteristics of AAT and CXE gene family members were different with fruit development,and correlation analysis suggested that CmCXE5,CmCXE6 and CmAAT5 were involved in the metabolism of eight different esters in oriental melon ripe fruits. From those findings,the variations in synthesis and accumulation of eight key esters are important reasons that direct the difference in aroma of two kinds of oriental melon,and CmCXE5,CmCXE6 and CmAAT5 may play a major regulatory role.更多还原