Alteration of pectin metabolism in blood orange fruit(Citrus sinensis cv.Tarocco)in response to vesicle collapse  

作　　者：Jiao Hou Dandan Yan Meizhu Huang Kaifang Zeng Shixiang Yao 侯娇;严丹丹;黄美珠;曾凯芳;姚世响(College of Food Science,Southwest University,Chongqing,China;Chongqing Key Laboratory of Speciality Food Co-Built by Sichuan and Chongqing,Chongqing,China;Food Storage and Logistics Research Center,Southwest University,Chongqing,China)

机构地区：[1]College of Food Science,Southwest University,Chongqing,China [2]Chongqing Key Laboratory of Speciality Food Co-Built by Sichuan and Chongqing,Chongqing,China [3]Food Storage and Logistics Research Center,Southwest University,Chongqing,China

出　　处：《Food Quality and Safety》2022年第4期629-637,共9页食品品质与安全研究（英文版）

基　　金：funded by the National Natural Science Foundation of China(No.32172262);the Fundamental Research Funds for the Central Universities(No.XDJK2021F008);Chongqing Graduate Student Research Innovation Project(No.CYS21118),China.

摘　　要：Segment drying is a severe physiological disorder of citrus fruit,and vesicles become granulated or collapsed.Aside from the hypothesis that alteration of cell wall metabolism is the main factor of citrus granulation,little is known about vesicle collapse.This study aimed to elucidate the changes in pectin metabolism during vesicle collapse in blood orange.Vesicle collapse was characterized by decreased nutrients and increased chelate-and sodium carbonate-soluble pectin and calcium content.The nanostructure of chelate-soluble pectin became complex and developed multi-branching upon collapse.The activity of pectin methylesterase increased,while that of polygalacturonase and pectate lyase decreased upon collapse.Genome-wide transcriptional analysis revealed an increasing pattern of genes encoding pectin methylesterase and other enzymes involved in pectin synthesis and demethylesterification upon collapse.Drying vesicles were characterized by increased abscisic acid content and relevant gene expression.In conclusion,we discovered alteration in pectin metabolism underlying citrus vesicle collapse,mainly promoting pectin demethylesterification,remodeling pectin structures,and further inhibiting pectin degradation,which was hypothesized to be a main factor for citrus collapse.This is the first study to disclose the potential intrinsic mechanism underlying vesicle collapse in orange fruit.

关 键 词：Citrus sinensis cv.Tarocco vesicle collapse pectin metabolism pectin methylesterase gene expression 

分 类 号：S66[农业科学—果树学]