【摘要】 植物多向耐药性（Pleiotropic drug resistance,PDR）蛋白属于三磷酸腺苷结合盒（ATP-binding cassette,ABC）转运蛋白ABCG亚族，在植物次生代谢产物转运特别是萜类物质跨膜转运中发挥重要作用。基于辽东楤木全基因组测序鉴定出21个PDR转运蛋白，且主要为细胞膜蛋白，该基因在12对染色体上均有分布，其中5号染色体上分布较多。共线性分析结果表明，部分PDR基因在进化过程中发生基因串联复制事件，并可能存在基因多拷贝扩增现象。基因结构分析结果表明，17个基因含有PDR基因特有结构域，且启动子上含有多种激素和非生物胁迫响应相关顺式作用元件。组织特异性表达模式分析结果表明，PDR基因主要在辽东楤木叶片中高表达。为筛选与辽东楤木三萜皂苷转运相关的PDR转运蛋白，对基因编码区序列、蛋白结构、跨膜螺旋等进行分析，初步筛选出7个结构完整的PDR转运蛋白。进一步通过系统进化分析、基因表达与皂苷含量的关联分析筛选出2个可能与楤木皂苷转运相关的PDR基因（AE02G00218和AE12G01725）。两个基因均受外源激素MeJA、SA和机械损伤诱导上调表达。以上研究为萜类物质转运相关蛋白鉴定与功能研究提供新思路和基因资源。更多还原

【Abstract】 The pleiotropic drug resistance(PDR) protein, belonging to the ATP-binding cassette(ABC) transporter protein ABCG subfamily, plays an important role in the transmembrane transport of secondary metabolites in plants, especially terpenoids. Based on the whole-genome sequencing of Aralia elata, 21 PDR transporters, which were predominantly cell membrane proteins, were identified.These genes were distributed on all 12 pairs of chromosomes, with a higher frequency on chromosome 5.Synteny analysis revealed that some PDR genes undergo tandem duplication events during evolution,suggesting gene duplication amplification. Gene structure analysis showed that 17 genes possessed PDR-specific domains, and their promoters contained various cis-acting elements involved in hormone and abiotic stress responses. Tissue-specific expression analysis indicated that PDR genes were predominantly expressed in the leaves of Aralia elata. To screen PDR proteins related to triterpenoid glycoside transport, analyses on coding sequences, protein structures and transmembrane domains were conducted, and seven structurally intact PDR transport proteins were identified. Through further systematic evolutionary analysis and correlation analysis between gene expression and saponin content, two PDR genes related to triterpenoid glycoside transport in Aralia elata(AE02G00218 and AE12G01725) were selected. These two genes were upregulated in response to exogenous hormones such as MeJA and SA, as well as mechanical damage. This study provided new insights and genetic resources for the identification and functional characterization of proteins involved in triterpenoid glycoside transport.更多还原