甜瓜CmMYBL基因调控类黄酮合成的功能分析  

Functional Analysis of CmMYBL Gene Regulating Flavonoid Synthesis in Melon(Cucumis melo)

作　　者：刘丽飞 张瑾 孟燕燕 郝源童 郝金凤[1] 哈斯阿古拉[1] Liu Lifei;Zhang Jin;Meng Yanyan;Hao Yuantong;Hao Jinfeng;Hasi Agula(Key Laboratory of Herbage and Endemic Crop Biotechnology,School of Life Sciences,Inner Mongolia University,Hohhot,010070)

机构地区：[1]内蒙古大学生命科学学院,牧草与特色作物生物技术重点实验室,呼和浩特010070

出　　处：《分子植物育种》2020年第16期5380-5388,共9页Molecular Plant Breeding

基　　金：内蒙古自然科学基金(2016MS0333);内蒙古自治区高等学校科学研究项目(NJZZ16016)共同资助。

摘　　要：MYB类转录因子对植物的次生代谢具有重要的调控作用,广泛地参与了类黄酮代谢途径,在植物果实品质调控及抗病性中发挥作用。本研究以甜瓜品种河套蜜瓜(Cucumis melo L. cv Hetao)为试材,对转录组数据中甜瓜果实成熟期高表达的CmMYBL (v-myb avian myeloblastosis viral oncogene homolog like gene)(MELONOMICS登录号:MELO3C003633)基因进行了克隆。利用实时荧光定量PCR技术对其在甜瓜果实发育成熟中的表达模式进行了分析,同时构建了基因的超表达及RNAi表达载体,利用子房注射法转化了甜瓜,经PCR及RT-qPCR方法检测,已经分别获得了2个转基因甜瓜株系。定量分析结果显示,该基因随着果实的成熟其表达量逐渐增加,在成熟时达到最大。对T2代转基因果实中类黄酮合成相关基因分析显示,超表达果实中查尔酮合成酶基因CmCHS (Chalcone synthase)、查尔酮异构酶基因CmCHI (Chalcone isomerase)和黄烷酮-3-羟基转移酶基因CmF3H (Flavanone-3-hydroxyltransferase)的表达量显著高于对照果实,而RNAi果实中CmCHS和CmCHI的表达量显著低于对照果实,CmF3H的表达量略低于对照果实。类黄酮含量分析显示,超表达CmMYBL基因的甜瓜果实中类黄酮含量显著增加,而RNAi果实的类黄酮含量相对较低。本研究初步鉴定出CmMYBL基因对甜瓜类黄酮的合成具有促进作用,为甜瓜类黄酮合成调控的研究提供了理论基础,同时为提高甜瓜果实品质的基因工程提供候选基因。MYB transcription factors are important to regulate plant secondary metabolism.They are involved in flavonoid metabolism pathways,and affect fruit development and quality accordingly.The CmMYBL gene was cloned frommeloncultivarHETAO(Cucumis meloL.cvHetao),whichwasexpressed highlyduringfruit ripeningin melon by transcriptome sequencing analysis.The expression was analyzed by RT-qPCR during melon development and ripening.The overexpression and RNAi vector were constructed,and transformed melon via ovary injection method.The two transgenic lines were obtained respectively through PCR and RT-qPCR detection.The transcript level of CmMYBL gene increases gradually with the fruit ripening,and reaches maximum at ripening.Expression of the genes CmCHS,CmCHI and CmF3H,coding enz ymes of the flavonoid pathway increased with the concentration of flavonoid in T 2 transgenic fruit of overexpression lines.In contrast,they decreased in RNAi lines.This study identified that CmMYBL gene could promote the synthetic of flavonoid in melon.This result provides a theoretical basis for clarifying the regulation of flavonoid synthesis in melon,and candidate genes to improve the quality of melon fruits.

关 键 词：甜瓜(Cucumis melo) CmMYBL基因 表达模式 类黄酮 表达调控 

分 类 号：S652[农业科学—果树学]