厚朴萜类合酶基因家族鉴定及表达模式分析

Identification and expression pattern of Magnolia officinalis terpenoid synthase gene family

关键词:  厚朴，萜类合酶(TPS)，基因家族，生物信息学，表达模式分析

Key words:  Magnolia officinalis, terpenoid synthase (TPS), gene family, bioinformatics, expression mode analysis

摘要:

萜类合酶(Terpenoid synthase, TPS)是合成萜类物质的关键酶，可以催化同一萜类前体物质形成不同的萜类骨架，也可以作用于多种底物，从而产生多样的萜类化合物。本研究通过生物信息学方法对厚朴MoTPS家族成员进行鉴定，并综合分析其理化性质、染色体定位、系统进化关系、保守基序、基因结构和顺式作用元件等，基于厚朴根、茎、叶、果实及不同时期厚朴花转录组数据，分析其在厚朴不同部位及不同时期厚朴花中的表达模式。结果表明：（1）在厚朴中共鉴定出55个MoTPS家族成员分布在10条染色体上。（2）保守基序及基因结构分析表明，MoTPS属于Ⅰ类TPS，motif数量在1~11个之间，且所有成员均包含典型的TPS保守基序，但不同MoTPS的内含子数量差异较大。（3）系统进化分析表明，MoTPS 共分为五个亚家族，其中TPS-a亚家族成员占比最高，为58.18%。（4）顺式作用元件分析表明，启动子区域包括光响应、激素调节、环境胁迫、植物生长发育、代谢等顺式作用元件，MoTPS在厚朴不同部位及不同发育阶段的厚朴花中的表达量存在显著差异， 表明MoTPS在厚朴各部位及不同花期可能存在功能的分化。本研究结果为深入探究厚朴MoTPS基因的功能、解析其在厚朴花香气物质生物合成和调控机制奠定基础。

Abstract:

Terpenoid synthase (TPS) is a key enzyme in terpenoid biosynthesis, catalyzing the formation of diverse terpene skeletons from common precursors to produce a wide array of terpenoid compounds. In this study, we identified the MoTPS gene family in Magnolia officinalis using bioinformatics approaches and systematically analyzed their physicochemical properties, chromosomal localization, phylogenetic relationships, conserved motifs, gene structures, and cis-acting elements. Based on transcriptome data from roots, stems, leaves, fruits, and flowers at different developmental stages, we further investigated their tissue-specific and floral stage-dependent expression patterns. The results were as follows: (1) A total of 55 MoTPS family members were identified on 10 chromosomes. (2) Conserved motif and gene structure analyses revealed that MoTPS proteins belong to class I TPS, containing 1-11 motifs, with all members harboring typical TPS conserved domains. However, the number of introns varied significantly among different MoTPS genes. (3) Phylogenetic analysis showed that MoTPS are divided into five subfamilies, with the TPS-a subfamily having the highest proportion of members at 58.18%. (4) Cis-acting element analysis showed that the promoter region included cis-acting elements for light response, hormone regulation, environmental stress. Expression profiling showed significant variations in MoTPS expression across different tissues and floral developmental stages, suggesting functional diversification of MoTPS genes in M. officinalis. This study provides a foundation for further functional characterization of MoTPS genes in M. officinalis and elucidates their roles in the biosynthesis and regulation of floral fragrance compounds.