小麦类胡萝卜素合成途径关键基因Lcye功能分析  

Functional analysis of Lcye gene involved in the carotenoid synthesis in common wheat

作　　者：翟胜男 郭军[1] 刘成[1] 李豪圣[1] 宋健民[1] 刘爱峰[1] 曹新有[1] 程敦公[1] 李法计 何中虎[2] 夏先春[2] 刘建军[1] ZHAI Sheng-Nan;GUO Jun;LIU Cheng;LI Hao-Sheng;SONG Jian-Min;LIU Ai-Feng;CAO Xin-You;CHENG Dun-Gong;LI Fa-Ji;HE Zhong-Hu;XIA Xian-Chun;LIU Jian-Jun(Crop Research Institute,Shandong Academy of Agricultural Sciences,Jinan 250100,Shandong,China;Institute of Crop Sciences,Chinese Academy of Agricultural Sciences,Beijing 100081,China)

机构地区：[1]山东省农业科学院作物研究所,山东济南250100 [2]中国农业科学院作物科学研究所,北京100081

出　　处：《作物学报》2020年第10期1485-1495,共11页Acta Agronomica Sinica

基　　金：国家自然科学基金项目(31701420);山东省农业科学院农业科技创新工程(CXGC2018E01);中国科协青年人才托举工程(2017QNRC001);山东省农业良种工程项目(2019LGC001)资助。

摘　　要：小麦籽粒黄色素是面粉及面制品黄度形成的主要原因,其主要成分是类胡萝卜素。ε-番茄红素环化酶(LCYE)是小麦类胡萝卜素生物合成途径的关键酶,前人对其研究多集中于QTL定位、基因克隆和分子标记开发,而基因功能和遗传调控机制尚不明确。本研究利用TILLING技术筛选EMS诱变群体,对Lcye功能及遗传调控机制进行研究,以期深入认识小麦籽粒黄色素含量形成的分子机制。在2491份M2代EMS诱变群体中共检测到21个Lcye基因的点突变,包含6个错义突变,2个同义突变和13个内含子突变,Lcye基因在该诱变群体中的突变频率为1/266.1 kb。PARSENP软件预测分析显示,M090815(C2202T)和M091648(G3284A)两个错义突变可能严重影响蛋白质功能。MEME分析结果表明,M090815和M092230(G2195A)突变位点位于Lcye基因保守结构域内。6个错义突变植株与野生型杂交构建的F2代群体中,M090815突变位点显著降低籽粒黄色素含量,证实该位点对LCYE功能具有重要影响。qRT-PCR(quantitative real-time PCR)分析也显示,M090815突变位点显著降低Lcye基因表达水平,且Lcye-B1和Lcye-D1基因表达降低趋势相似,而Lcye-A1在花后14~28 d表现出补偿效应。本研究不仅验证Lcye基因功能,也为面粉及其制品颜色性状改良提供了理论依据和种质资源。Yellow pigment in wheat grains,mostly composed of carotenoids,is a main factor for the yellowness of flour and its end-used products.Lycopene epsilon cyclase(LCYE)is a key enzyme for the carotenoid biosynthesis pathway in wheat.Previous studies of Lcye gene mainly focused on QTL mapping,gene cloning,and molecular marker development,but its function and genetic regulatory mechanisms remained unclear.In the present study,in order to further understanding the molecular mechanism of yellow pigment formation in wheat grains,the function and genetic regulation of Lcye were studied by TILLING to screen the EMS-mutagenised population.A total of 21 Lcye mutations including six missense mutations,two synonymous mutations and 13 intron mutations were detected consisted from 2491 M2 EMS-mutagenised population.The mutation frequency of Lcye in the population was 1/266.1 kb.Two missense mutations(M090815 and M091648)were predicted to have severe effects on LCYE protein function based on PARSENP software.MEME analysis showed that the mutation sites of M090815 and M092230 were located on the conserved domain of Lcye gene.In F2 populations crossing by six missense mutants and the wild type,C2202T mutation in M090815 significantly reduced yellow pigment content in grains,indicating the mutation played an important effect on LCYE function.The quantitative real-time PCR(qRT-PCR)results also showed that the expression level of Lcye gene were significantly reduced,and the decrease trend of Lcye-B1 and Lcye-D1 expression level was similar during different seed developmental stages,while the expression level of Lcye-A1 exhibited a compensation effect at 14–28 days post anthesis.This study identified Lcye gene function,and provided germplasms and a theoretical basis for the improvement of flour color traits and end-used products.

关 键 词：EMS TILLING 面粉颜色 黄色素含量 遗传育种 

分 类 号：S512.1[农业科学—作物学]