Natural Variation in CCD4 Promoter Underpins Species-Specific Evolution of Red Coloration in Citrus Peel  

作　　者：Xiongjie Zheng Kaijie Zhu Quan Sun Weiyi Zhang Xia Wang Hongbo Cao Meilian Tan Zongzhou Xie Yunliu Zeng Junli Ye Lijun Chai Qiang Xu Zhiyong Pan Shunyuan Xiao Paul D.Fraser Xiuxin Deng 

机构地区：[1]Key Laboratory of Horticultural Plant Biology(Ministry of Education),Huazhong Agricultural University.Wuhan,China [2]School of Biological Sciences.Royal Holloway,University of London,Egham,Surrey TW20 OEX,UK [3]Department of Plant Science and Landscape Architecture,Institute for Bioscience and Biotechnology Research,University of Maryland,Rockville,MD,USA [4]Present address:College of Horticulture,Agricultural University of Hebei.Baoding Hebei 071000,China [5]Present address:Key Laboratory of Biology and Genetic Improvement of Oil Crops,Ministry of Agriculture.Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences,Wuhan 430070,China

出　　处：《Molecular Plant》2019年第9期1294-1307,共14页分子植物（英文版）

基　　金：the National Key R&D Program of China(2018YFD1000200);the National Natural Science Foundation of China(no.31630065,31330066 and 31521092)China Agriculture Research System(CARS-27);the 111 project(B13034),and a China Council Scholarship(to X.Z.).

摘　　要：Carotenoids and apocarotenoids act as phytohormones and volatile precursors that influence plant development and confer aesthetic and nutritional value critical to consumer preference.Citrus fruits display considerable natural variation in carotenoid and apocarotenoid pigments.In this study,using an integrated genetic approach we revealed that a 5;c/s-regulatory change at CCD4b encoding CAROTENOID CLEAVAGE DIOXYGENASE 4b is a major genetic determinant of natural variation in C3 0 apocarotenoids responsible for red coloration of citrus peel.Functional analyses demonstrated that in addition the known role in synthesizing 3-citraurin,CCD4b is also responsible for the production of another important C3 0 apocarotenoid pigment,p-citraurinene.Furthermore,analyses of the CCD4b promoter and transcripts from various citrus germplasm accessions established a tight correlation between the presence of a putative 5'c/s-regulatory enhancer within an MITE transposon and the enhanced allelic expression of CCD4b in C3 0 apocarotenoid-rich red-peeled accessions.Phylogenetic analysis provided further evidence that functional diversification of CCD4b and naturally occurring variation of the CCD4b promoter resulted in the stepwise evolution of red peels in mandarins and their hybrids.Taken together,our findings provide new insights into the genetic and evolutionary basis of apocarotenoid diversity in plants,and would facilitate breeding efforts that aim to improve the nutritional and aesthetic value of citrus and perhaps other fruit crops.

关 键 词：citrus apocarotenoid natural variation CAROTENOID CLEAVAGE DIOXYGENASE PROMOTER TRANSPOSON 

分 类 号：S66[农业科学—果树学]