| 摘要: |
| 摘 要：R2R3-MYB转录因子在植物的生长发育、逆境响应及次生代谢等过程具有重要的调控作用。为了探究太子参中R2R3-MYB转录因子的时空表达模式并筛选参与调控环肽B生物合成的R2R3-MYB转录因子，该文基于太子参的全长转录组数据库，从太子参中鉴定到15个R2R3-MYB转录因子，利用生物信息学方法对其理化性质、保守基序和系统进化进行分析，并运用qRT-PCR对其组织表达和激素脱落酸（abscisic acid，ABA）诱导的表达模式进行研究。结果表明：（1）15个PhR2R3-MYB蛋白亚细胞定位于细胞核，大部分PhR2R3-MYB蛋白为不稳定性亲水蛋白。与拟南芥R2R3-MYB蛋白一同构建系统进化树，可将PhR2R3-MYB蛋白分为8个亚组，其中有6个亚组能分别与拟南芥R2R3-MYB转录因子聚类。（2）PhR2R3-MYB基因在太子参植物中具有组织表达特异性，其中2个基因——PhMYB4和PhMYB8在块根韧皮部中特异性高表达。相关性分析显示，PhMYB4和PhMYB8基因表达量与太子参中环肽B含量及prePhHB基因表达量均呈显著正相关，推测PhMYB4和PhMYB8可能参与了太子参中环肽B的生物合成调控。（3）ABA处理后，PhMYB4基因呈现出先降低后升高的表达趋势，而PhMYB8基因的表达受到了抑制，表明 PhMYB4和PhMYB8基因均响应ABA信号。该研究结果为后续探究PhR2R3-MYB基因的功能奠定了基础，也为研究PhR2R3-MYB转录因子调控环肽B生物合成的分子机制提供了理论依据。 |
| 关键词: 太子参，R2R3-MYB转录因子，环肽B，生物信息学分析，表达分析 |
| DOI：10.11931/guihaia.gxzw202405051 |
| 分类号: |
| 基金项目:国家自然科学基金地区项目（82160728，82160716）；贵州省基础研究项目（黔科合基础-ZK[2022]一般464）；贵州省教育厅高校科研平台（黔教技[2022]021号） |
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| Identification and expression analysis of R2R3-MYB transcription factor in Pseudostellaria heterophylla |
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Huang Yishu, He Hua, Zhou Tao, Pan Qi, Liu Hongxia, Xu Jiao, Ou Xiaohong, Jiang Weike*
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Guizhou University of Traditional Chinese Medicine
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| Abstract: |
| R2R3-MYB transcription factor plays an important role in plant growth and development, stress response, and secondary metabolism. In order to explore the temporal and spatial expression pattern of R2R3-MYB transcription factors in Pseudostellaria heterophylla and screen R2R3-MYB transcription factors involved in the regulation of heterophyllin B biosynthesis, fifteen R2R3-MYB transcription factors were identified from P. heterophylla based on the full-length transcriptome database. Their physical and chemical properties, conserved motifs and phylogenetic relationships were analyzed by bioinformatics methods, and their tissue expression and abscisic acid induced expression patterns were studied by qRT-PCR. The results were as follows: (1) 15 PhR2R3-MYB proteins subcellular were predicted to locate in cell nucleus, and most of them were unstable hydrophilic proteins. By constructing phylogenetic tree with Arabidopsis R2R3-MYB protein, PhR2R3-MYB proteins can be divided into 8 subgroups, of which 6 subgroups can be clustered with Arabidopsis R2R3-MYB transcription factors respectively. (2) PhR2R3-MYB gene has tissue expression specificity in P. heterophylla, and two of the genes, PhMYB4 and PhMYB8, are highly expressed in phloem of tuberous root. Correlation analysis showed that PhMYB4 and PhMYB8 gene expression were significantly positively correlated with heterophyllin B content and prePhHB gene expression in P. heterophylla, suggesting that PhMYB4 and PhMYB8 might be involved in the regulation of heterophyllin B biosynthesis in P. heterophylla. (3) PhMYB4 and PhMYB8 gene were differentially expressed in response to ABA treatment for different time. The expression of PhMYB4 gene decreased first and then increased, while the expression of PhMYB8 gene was inhibited with ABA treatment, indicating that both PhMYB4 and PhMYB8 genes respond to ABA signals. This study will lay a foundation for further investigation of the function of PhR2R3-MYB gene, and also provides a theoretical basis for revealing the mechanism of R2R3-MYB transcription factor involved in the regulation of heterophyllin B biosynthesis. |
| Key words: Pseudostellaria heterophylla, R2R3-MYB transcription factor, Heterophyllin B, Bioinformatic analysis, Expression analysis |
