不同产地浙贝母生物碱含量及其合成相关基因表达研究

为了探究浙贝母(Fritillaria thunbergii)药效成分积累量与生物碱合成相关基因表达水平之间的关系,该研究采用UPLC-MS、qPCR技术分别测定不同产地11个样品中总生物碱(贝母素甲和贝母素乙之和)含量和3个参与生物碱合成途径相关基因(HMGR、FPS和DXR)的表达量,同时运用生物统计学方法分析成熟期鳞茎生物碱含量与各基因表达量之间的相关性。结果表明:不同产地浙贝母成熟期鳞茎总生物碱含量存在显著差异(P<0.05),为0.2105% ～ 0.4612%; HMGR和FPS基因在盛花期组织表达、盛花期至成熟期鳞茎表达变化趋势同生物碱含量变化趋势基本一致; DXR基因在成熟期鳞茎中表达量最高,盛花期组织表达、盛花期至成熟期鳞茎表达变化趋势同生物碱含量变化趋势大体不一致; HMGR、FPS基因表达量分别与贝母素甲、贝母素乙和总生物碱含量呈显著或极显著正相关性(P<0.05或P<0.01),以FPS基因表达量与生物碱含量相关系数为最高,相关系数分别为0.672,0.631,0.664,DXR基因与生物碱含量呈低度相关性。由此可以推断,生物碱的积累受MVA途径中HMGR、FPS基因协同调控或者修饰作用明显,受MEP途径中DXR基因调控作用不明显。

Alkaloid content and synthesis related gene expression of Fritillaria thunbergii in different producing areas

In order to explore the relationship between the accumulation of medicinal components and the expression level of alkaloid synthesis related genes in Fritillaria thunbergii, ultra high performance liquid chromatography mass spectrometry(UPLC-MS)and real-time quantitative PCR(qPCR)techniques were used to determine the total alkaloids(the sum of peimine and peiminine)and the expression level of three genes involved in alkaloid synthesis pathway(HMGR, FPS and DXR)in eleven samples from different producing areas. Meanwhile, biostatistics was used to analyze the correlation between the alkaloid content of mature bulbs and the expression of each gene. The results were as follows: There were significant differences in total alkaloid content of mature bulbs(P<0.05), ranging from 0.2105% to 0.4612%; The variation trend of the expression of HMGR and FPS genes in the tissue of full-bloom stage and the bulbs from full-bloom stage to maturity stage was basically consistent with the variation trend of alkaloid content; The expression of DXR gene was the highest in mature bulbs, and the change trend of the tissue expression at the full-bloom stage and the bulb expression from the full-bloom stage to maturity stage was generally inconsistent with the change trend of alkaloid content; The expression levels of HMGR and FPS genes were significantly or extremely significantly positively correlated with peimine, peiminine and total alkaloid content, respectively(P<0.05 or P<0.01), and the coefficients between FPS gene expression and alkaloid content were the highest, which were 0.672, 0.631, 0.664, respectively, meanwhile, the coefficients between DXR gene expression and alkaloid content were low. In summary, the data indicate the accumulation of alkaloids is significantly regulated or modified by HMGR and FPS genes in the MVA pathway, but not by DXR genes in the MEP pathway.