| 摘要: |
| 花青苷物质是影响红花檵木（Loropetalum chinense var. rubrum）观赏价值形成的关键因素之一。为探究红花檵木花青苷合成的分子机制，该研究从红花檵木中克隆了的1个花青苷合成相关的R2R3-MYB基因，命名为LcMYB113（GenBank序列号：OR344758），并初步分析了其生物信息学、红花檵木和白花檵木叶片中的LcMYB113的表达水平、转基因烟草株系的表型及花青苷合成结构基因的表达。结果表明：（1）LcMYB113基因开放阅读框全长为789 bp，编码262个氨基酸，其N端含有R2R3 DNA结合域和bHLH转录因子的结合基序[D/E]Lx2[R/K]x3Lx6Lx3R，同时还具有花青苷正调控相关的2个特征基序ANDV和[K/R]P[Q/R]P[Q/R]。系统进化树分析表明，LcMYB113与牡丹的PsMYB58、葡萄的VvMYBA1等多种植物的花青苷特异调控R2R3-MYB转录因子的亲缘关系较近。（2）红花檵木叶片中的花青苷含量为白花檵木中的7.4倍，LcMYB113基因在红花檵木叶片中的相对表达量为白花檵木的101倍，表明LcMYB113基因的表达与花青苷含量趋势相一致。（3）通过构建基因过表达载体并转化烟草，烟草中过表达LcMYB113基因能够诱导转基因株系叶片和花朵中花青苷物质的积累，同时NtANS、NtDFR、NtCHS等多个花青苷生物合成结构基因在叶片中的相对表达量相比于野生型株系显著增加。以上研究结果表明LcMYB113能够调控花青苷物质的合成，为红花檵木的叶色育种提供理论支持。 |
| 关键词: 红花檵木,花青苷,LcMYB113基因,实时荧光定量RT-PCR |
| DOI：10.11931/guihaia.gxzw202405037 |
| 分类号: |
| 基金项目:国家自然科学基金(32100576)；湖南省自然科学基金(2024JJ4018,2024JJ7156),湖南省教育厅基金(23B0541) |
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| Function of R2R3-MYB Gene LcMYB113 on Regulating Anthocyanin Biosynthesis in Loropetalum chinense var. rubrum |
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LU Peng, RONG Duoyan1, LIAO Xiaoshan2, XIAO Yangyao1, ZHANG Bangyue1*
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1. Provincial Engineering Research Center of Lily Germplasm Resource Innovation and Deep Processing, College of Life Sciences and Chemistry, Hunan University of Technology, Zhuzhou 412007, Hunan, China; 2. Zhuzhou Institute of Agricultural Sciences,Zhuzhou412007 , Hunan, China
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| Abstract: |
| Anthocyanin plays one of the key factors in determining ornamental value of Loropetalum chinense var. rubrum. In order to investigate the molecular mechanisms of anthocyanin biosynthesis in L. chinense var. rubrum, an anthocyanin biosynthesis relative R2R3-MYB gene, named LcMYB113 with GenBank accession number OR344758, was cloned from L. chinense var. rubrum. The deduced amino acid sequence of LcMYB113 gene was analyzed by bioinformatics methods. The relative expression levels of LcMYB113 gene in leaves of L. chinense var. rubrum and L. chinense were tested by real-time quantitative RT-PCR method. The phenotypes of leaves and flowers of transgenic tobacco lines were recorded. The relative expression levels of anthocyanin biosynthetic structural genes in leaves of transgenic tobacco lines were examined. The results were as follows: (1) The open reading frame of LcMYB113 gene was 789 bp, encoding 262 amino acids. Multiple alignment analysis showed that the N-terminal of LcMYB113 contained a canonical R2R3 DNA binding domain and a bHLH transcript factor binding motif [D/E]Lx2[R/K]x3Lx6Lx3R. Two anthocyanin biosynthesis activator characteristic motifs ANDV and [K/R]P[Q/R]P[Q/R] were also found in the amino acid sequence of LcMYB113. Phylogenetic tree analysis indicated that LcMYB113 was closely related to anthocyanin specific R2R3-MYB subfamily transcription factors, including PsMYB58 of Paeonia suffruticosa and VvMYBA1 of Vitis vinifera. (2) The anthocyanin content and relative expression level of LcMYB113 gene in leaves of L. chinense var. rubrum were 7.4 and 101 times that of L. chinense respectively, which indicated that the relative expression levels of LcMYB113 gene was correlated with the anthocyanin content in leaves. (3) The LcMYB113 gene overexpression vector was constructed and transformed into tobacco variety WS38. Heterologous expression of LcMYB113 gene in tobacco induced anthocyanin accumulation in leaves and flowers of transgenic lines. Further more, compared with wide type tobacco line, transgenic lines had remarkably higher relative expression levels of anthocyanin biosynthetic structural genes, such as NtANS, NtDFR and NtCHS. In summary, this research results indicate that LcMYB113 can regulate the biosynthesis of anthocyanin, providing theoretical support for leaf color breeding of L. chinense var. rubrum. |
| Key words: Loropetalum chinense var. rubrum,anthocyanin,LcMYB113 gene,real time quantitative RT-PCR |
