College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, 310018, China.
State Key Laboratory for Managing Biotic and Chemical Threats To the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, 198 Shiqiao Road, Hangzhou, 310021, China.
Planta. 2021 Apr 7;253(5):93. doi: 10.1007/s00425-021-03607-2.
Genome-wide identification, expression analysis of the MYC family in Camellia sinensis, and potential functional characterization of CsMYC2.1 have laid a solid foundation for further research on CsMYC2.1 in jasmonate (JA)-mediated response. Myelocytomatosis (MYC) of basic helix-loop-helix (bHLH) plays a major role in JA-mediated plant growth and developmental processes through specifically binding to the G-box in the promoters of their target genes. In Camellia sinensis, studies on the MYC gene family are limited. Here, we identified 14 C. sinensis MYC (CsMYC) genes, and further analyzed the evolutionary relationship, gene structure, and motif pattern among them. The expression patterns of these CsMYC genes in different tissues suggested their important roles in diverse function in tea plant. Four MYC transcription factors with the highest homology to MYC2 in Arabidopsis were localized in the nucleus. Two of them, named CsMYC2.1 and CsMYC2.2, exhibited transcriptional self-activating activity, and, therefore, could significantly activate the promoter containing G-box motif, whereas CsJAM1.1 and CsJAM1.2 lack the transcriptional self-activating activity, indirectly mediating the JA pathway through interacting with CsMYC2.1 and CsMYC2.2. Furthermore, Yeast Two-Hybrid (Y2H) and Bimolecular Fluorescent Complimentary (BiFC) assays showed that CsMYC2.1 could interact with CsJAZ3/7/8 proteins. Genetically, the complementation of CsMYC2.1 in myc2 mutants conferred the ability to restore the sensitivity to JA signals. The results provide a comprehensive characterization of the 14 CsMYCs in C. sinensis, establishing a solid foundation for further research on CsMYCs in JA-mediated response.
在茶树中，全基因组鉴定、表达分析 MYC 家族和 CsMYC2.1 的潜在功能特征，为进一步研究茉莉酸（JA）介导的响应中的 CsMYC2.1 奠定了坚实的基础。碱性螺旋-环-螺旋（bHLH）的髓母细胞瘤（MYC）通过特异性结合其靶基因启动子中的 G 盒，在 JA 介导的植物生长和发育过程中发挥主要作用。在茶树中，对 MYC 基因家族的研究有限。在这里，我们鉴定了 14 个茶树 MYC（CsMYC）基因，并进一步分析了它们之间的进化关系、基因结构和基序模式。这些 CsMYC 基因在不同组织中的表达模式表明它们在茶树的多种功能中具有重要作用。与拟南芥中的 MYC2 同源性最高的四个 MYC 转录因子定位于细胞核中。其中两个，命名为 CsMYC2.1 和 CsMYC2.2，表现出转录自激活活性，因此可以显著激活含有 G 盒基序的启动子，而 CsJAM1.1 和 CsJAM1.2 缺乏转录自激活活性，通过与 CsMYC2.1 和 CsMYC2.2 相互作用间接介导 JA 途径。此外，酵母双杂交（Y2H）和双分子荧光互补（BiFC）实验表明，CsMYC2.1 可以与 CsJAZ3/7/8 蛋白相互作用。遗传上，CsMYC2.1 在 myc2 突变体中的互补赋予了恢复对 JA 信号敏感性的能力。这些结果全面描述了茶树中的 14 个 CsMYCs，为进一步研究 JA 介导的响应中的 CsMYCs 奠定了基础。
