中国水仙R2R3-MYB基因NtMYB5的克隆和功能研究  

Cloning and Functional Analysis of R2R3-MYB Gene NtMYB5 in Narcissus tazetta var. chinensis

作　　者：吴嘉诚 王桂青 Muhammad Anwar 曾黎辉[1] WU Jiacheng;WANG Guiqing;Muhammad Anwar;and ZENG Lihui(College of Horticulture,Fujian Agriculture and Forestry University,Fuzhou 350002,Chin)

机构地区：[1]福建农林大学园艺学院,福州350002

出　　处：《园艺学报》2018年第7期1327-1337,共11页Acta Horticulturae Sinica

基　　金：福建农林大学科技创新基金项目(KFA17352A);福建农林大学国际科技合作与交流项目(Kxb16013A); 福建省自然科学基金项目(2016J01109)

摘　　要：为研究中国水仙(Narcissus tazetta var.chinensis)中类黄酮代谢途径的调控网络,从其转录组中筛选出1条R2R3-MYB基因并从花瓣cDNA中克隆其编码区全长序列,命名为NtMYB5。NtMYB5开放阅读框为681 bp,编码226个氨基酸。蛋白多重序列比对分析发现NtMYB5含有R2和R3结构域以及1个pd LNLD/ELxiG/S氨基酸基序;系统进化树分析表明,NtMYB5与花青素合成抑制因子亲缘关系最近;通过对NtMYB5在中国水仙中的表达检测发现,其表达量在花器官中较高,且随花开放逐渐上升;在烟草瞬时表达中,NtMYB5显著抑制花青素合成促进因子St MYB的效果;转NtMYB5烟草花瓣颜色变浅,q PCR检测表明NtMYB5抑制类黄酮代谢途径大部分结构基因表达。NtMYB5为中国水仙中花青素合成抑制因子。A R2R3-MYB-like gene,named NtMYB5,was selected from transcriptome of Narcissus tazetta var. chinensis and was cloned in order to study its function in flavonoid metabolic pathway. Multiple alignments showed that NtMYB5 contained R2-domain and R3-domain. A pd LNLD/ELxiG/S motif was also found near the C-terminal. Phylogenetic tree analysis indicated that NtMYB5 was closely related to negative regulators of anthocyain biosynthesis. The expression level of NtMYB5 was higher in perianth and corona,and increased during the process of flowering. The accumulation of anthocyanin activated by St MYB was suppressed by NtMYB5 in the transient expression of tobacco. Transgenic tobacco plants were obtained and the flower colour of transgenic plants became lighter. The results of quantitative real-time PCR indicated that most structural genes involved in the anthocyanin pathway were down-regulated by NtMYB5. This study suggests that NtMYB5 is a repressor of anthocyanin biosynthesis in Chinese narcissus.

关 键 词：中国水仙 R2R3-MYB 花青素合成抑制因子 结构基因表达 

分 类 号：S682.21[农业科学—观赏园艺]