基于广泛靶向代谢组学的血橙枯水时柠檬酸降解途径研究  

Study on Citric Acid Degradation Pathways of Blood Orange DuringSegment Drying Based on Widely Targeted Metabolomics

作　　者：张皓月 侯娇 杨相政[2] 李健[3] 曾凯芳[1] 姚世响[1] ZHANG Haoyue;HOU Jiao;YANG Xiangzheng;LI Jian;ZENG Kaifang;YAO Shixiang(College of Food Science/National Citrus Engineering Research Center/Chongqing Key Laboratory of Speciality Food Co-Built by Sichuan and Chongqing,Southwest University,Chongqing 400715,China;Jinan Fruit Research Institute,All China Federation of Supply&Marketing Cooperatives,Ji nan 250204,China;Beijing Engineering and Technology Research Center of Food Additives,Beijing Technology and Business University,Beijing 100048,China)

机构地区：[1]西南大学食品科学学院/国家柑桔工程技术研究中心/川渝共建特色食品重庆市重点实验室,重庆400715 [2]中华全国供销合作总社济南果品研究所,山东济南250204 [3]北京工商大学北京市食品添加剂工程技术研究中心,北京100048

出　　处：《食品科学技术学报》2023年第6期75-87,共13页Journal of Food Science and Technology

基　　金：国家自然科学基金面上项目(31972131);国家自然科学基金青年基金项目(31601520)。

摘　　要：枯水是影响柑橘果实品质的主要生理性病害,果实发病后风味寡淡,不堪食用。枯水主要类型为汁胞粒化型枯水和汁胞萎缩型枯水,后者研究较少。以汁胞萎缩型枯水的塔罗科血橙为实验材料,运用广泛靶向代谢组学分析汁胞萎缩型枯水的初生代谢物及代谢途径变化,并进一步结合氨基酸含量、关键酶活性及基因表达分析解析枯水时柠檬酸降解机制。研究结果表明:有193种初生代谢物的含量在汁胞枯水时显著变化,其中柠檬酸含量显著下降了53.1%,乙酰辅酶A途径代谢产物丝氨酸、亚油酸及其他脂类物质的含量显著升高;脂代谢基因在枯水时上调表达;编码ATP-柠檬酸裂解酶的基因CsACLs的表达没有变化;谷氨酰胺合成酶活性在枯水时增加了75.3%;γ-氨基丁酸含量没有变化,谷氨酰胺脱羧酶活性没有变化,编码谷氨酰胺脱羧酶的基因CsGADs在枯水时下调表达。研究表明,乙酰辅酶A合成途径是血橙汁胞萎缩型枯水时柠檬酸快速降解的主要机制,结果旨在为明确柑橘枯水机制提供一定的参考。Segment drying is the major physiological disorder that deteriorates fruit quality and results in loss of flavor and edible value of fruits,including mainly granulation-type segment drying and collapse-type segment drying.Few research had been focused on the latter.Using Tarocco blood orange upon collapse-type segment drying as study material,widely targeted metabolomics was used to analysis primary metabolite and metabolic pathway changes of collapse-type segment drying,amino acid content analysis,enzyme activity assay,and gene expression analysis were utilized to elucidate the mechanism underlying the rapid deterioration of citric acid during segment drying.The results showed that a total of 193 differentially primary metabolites were identified in juice vesicles upon segment drying,citric acid content significantly decreased by 53.1%,the metabolites relative to the acetyl-CoA synthesis pathway(such as serine,linoleic acid and other lipids)increased significantly,the gene expression of lipid metabolism was up-regulated upon segment drying,while the expression of gene CsACLs encoding ATP-citrate lyase remained unchanged.Glutamine synthetase activity increased by 75.3%in vesicles upon segment drying.γ-Aminobutyric acid content remained unchanged,glutamine decarboxylase activity was not changed,the expression of gene CsGADs encoding glutamine decarboxylase was down-regulated upon segment drying.In conclusion,the acetyl coenzyme A synthesis pathway was the main pathway for the rapid degradation of citric acid in vesicles of blood orange during collapse-type segment drying.The results aimed to provide a reference for clarifying the mechanism of collapse-type segment drying in citrus fruit.

关 键 词：塔罗科血橙 枯水 柠檬酸降解 乙酰辅酶A合成途径 GABA支路 

分 类 号：TS255.3[轻工技术与工程—农产品加工及贮藏工程]