白芍单萜苷成分与生物合成相关基因的时空表达特性及其相关性研究

目的 揭示白芍不同发育时期不同组织部位中单萜苷含量及其生物合成基因的表达差异和两者之间的相关性。方法 通过HPLC测定白芍叶、花、果、根及根中不同部位(韧皮部、木质部、须根和根皮)在不同发育时期氧化芍药苷、白芍内酯苷、芍药苷和苯甲酰芍药苷含量。采用RT-PCR对筛选出来的8个白芍单萜苷生物合成相关基因进行相对含量测定。应用R语言分析4种单萜苷含量与各生物合成相关基因表达量的相关性。结果 芍药苷和苯甲酰芍药苷主要分布于根中，而氧化芍药苷和白芍内酯苷主要分布于花中。氧化芍药苷、芍药苷和苯甲酰芍药苷主要分布于木质部中，白芍内酯苷主要在韧皮部和须根。4种单萜苷成分在根中花期和果期含量均较低，在黄枯期中最高，展叶期次之。单萜苷含量与其关键酶基因表达量相关性分析结果表明，HMGR2和IDI基因与芍药苷、苯甲酰芍药苷和氧化芍药苷含量呈高度正相关。结论 白芍单萜苷及其生物合成相关基因存在时空特异表达模式，甲羟戉酸途径是白芍中生物合成萜类骨架的主要途径。

Study on the Spatio-temporal Expression Pattern and Their Correlation of Monoterpene Glycosides Content and the Biosynthesis-related Gene in Paeonia Lactiflora Pall.

OBJECTIVE To study the expression pattern of monoterpene glycosides contents and their biosynthesis-related genes in different tissues of Paeonia lactiflora Pall. at different developmental stages, investigate the correlation between them.METHODS The content of oxypaeoniflorin, albiflorin, paeoniflorin and benzoylpaeoniflorin in root, leaf, flower, fruit and different tissues(phloem, xylem, fibril and velamen) of the root was determined by HPLC. RT-PCR was used to analyze the candidate genes related to biosynthesis of monoterpene glycosides. The correlation between the contents of four monoterpene glycosides and the expression levels of biosynthesis related genes was comprehensively analyzed by R language. RESULTS Paeoniflorin and benzoylpaeoniflorin were mainly distributed in roots, while oxypaeoniflorin and albiflorin were mainly distributed in flowers. Oxypaeoniflorin, paeoniflorin and benzoylpaeoniflorin were mainly distributed in xylem, while albiflorin was mainly distributed in phloem and fibrous roots. The contents of the four monoterpene glycosides in root were low in flowering and fruit stage, and the highest in withered stage, followed by leaf spreading stage. The correlation analysis between monoterpene glycosides content and the expression level of key enzyme genes showed that HMGR2 and IDI genes were closely positively correlated with the contents of paeoniflorin, benzoylpaeoniflorin and paeoniflorin. CONCLUSION Monoterpene glycosides and their biosynthesis related genes in P. lactflora showed spatio-temporal expression patterns, and mevalonate pathway is the main pathway for biosynthesis of terpenoid skeleton in P. lactiflora.