College of Chemistry, Chemical Engineering and Resource Utilization, Northeast Forestry University, Harbin, 150040, China.
Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin, 150040, China.
Planta. 2021 Sep 6;254(4):64. doi: 10.1007/s00425-021-03713-1.
Thirty CcMYB were identified to involve in flavonoid and lignin biosynthesis in pigeon pea genome. A comprehensive analysis of gene structure, phylogenetic relationships, distribution on chromosomes, gene duplication, and expression patterns was performed. MYB transcription factor is one of the largest gene families in plants and plays critical roles in plant growth and development, as well as resistance to biotic and abiotic stress. However, the function of MYB genes in pigeon pea (Cajanus cajan) remains largely unknown. Here, 30 R2R3-MYB which involved flavonoid and lignin biosynthesis were identified in the pigeon pea genome and were classified into five groups based on phylogenetic analysis. Simultaneously, another 122 key enzyme genes from biosynthetic pathways of flavonoid and lignin were identified and all of them were mapped on 11 chromosomes with the co-linearity relationship. Among these genes, the intron/exon organization and motif compositions were conserved and they have undergone a strong purifying selection and tandem duplications during evolution. Expression profile analysis demonstrated most of these genes were expressed in different tissues and responded significantly to MeJA, RNA-seq analysis revealed clear details of genes varied with time of induction. Ten key genes from the phenylpropanoid pathway were selected to further verify whether they responded to induction under different abiotic stress conditions (UV-B, cold, heat, salt, drought, and GA). This study elaborates on potential regulatory relationships between R2R3-MYB genes and some key genes involved in flavonoid and lignin biosynthesis under MeJA treatment, as well as adding to the understanding of improving abiotic stress tolerance and regulating the secondary metabolism in woody crops. A simplified discussion model for the different regulation networks involved with flavonoid and lignin biosynthesis in pigeon pea is proposed.
在木豆基因组中鉴定出 30 个 CcMYB 参与类黄酮和木质素生物合成。对基因结构、系统发育关系、染色体分布、基因复制和表达模式进行了全面分析。MYB 转录因子是植物中最大的基因家族之一，在植物生长发育以及对生物和非生物胁迫的抗性中起着关键作用。然而，MYB 基因在木豆（Cajanus cajan）中的功能仍然知之甚少。在这里，在木豆基因组中鉴定出 30 个涉及类黄酮和木质素生物合成的 R2R3-MYB，并根据系统发育分析将它们分为五个组。同时，还鉴定出黄酮类和木质素生物合成途径中的另外 122 个关键酶基因，并将它们全部映射到 11 条染色体上，具有共线性关系。在这些基因中，内含子/外显子组织和基序组成保守，它们在进化过程中经历了强烈的纯化选择和串联复制。表达谱分析表明，这些基因中的大多数在不同组织中表达，并对 MeJA 有明显的响应，RNA-seq 分析显示，随着诱导时间的变化，基因的表达情况发生了明显的变化。从苯丙烷途径中选择了 10 个关键基因，以进一步验证它们是否在不同的非生物胁迫条件（UV-B、寒冷、高温、盐、干旱和 GA）下对诱导有反应。本研究阐述了 R2R3-MYB 基因与 MeJA 处理下参与类黄酮和木质素生物合成的一些关键基因之间的潜在调控关系，并增加了对提高木本作物非生物胁迫耐受性和调节次生代谢的理解。提出了一个简化的讨论模型，用于解释木豆中类黄酮和木质素生物合成涉及的不同调控网络。
