温差和水分对黄连生物碱合成基因表达的影响

Effects of diurnal temperature difference and water on expression of genes for alkaloid synthesis in Coptis chinensis

探究昼夜温差和水分缺失对黄连生物碱合成关键基因表达的影响。以昼夜温差条件下以及水分缺失条件下黄连植株为实验组,无昼夜温差以及正常水分条件下黄连植株为对照组,每隔7 d对黄连根茎叶组织进行采样,提取其总RNA,实时荧光定量检测黄连生物碱合成途径中6个具有重要功能的关键基因表达水平。昼夜温差处理后,黄连根茎叶中关键基因的相对表达量均高于对照组,说明昼夜温差处理可诱导关键基因的表达。而水分缺失情况下催化四氢氧化物氧化的关键基因表达量显著高于对照组,在恢复浇水之后,其表达量反而降低。催化亚甲基二氧桥的4个关键基因,其表达量随着时间的推移均升高,但在经过水分缺失处理后其表达量均显著低于对照组,说明水分的缺失会使其表达量降低。昼夜温差处理对关键基因具有直接特异诱导的作用,而水分的缺失则会增加催化四氢氧化物氧化的关键基因的表达量,而使催化亚甲基二氧桥关键基因的表达量降低。

To investigate the effects of diurnal temperature difference and water deficiency on the expression of key genes for alkaloid synthesis in Coptis chinensis.The C.chinensis plants under diurnal temperature difference and water deficiency conditions were used as the experimental group,and that under no diurnal temperature difference and normal water conditions were used as the control group.The root,stem and leaf tissues of C.chinensis were sampled every 7 days to extract the total RNA.Real-time PCR was used to detect the expression level changes of 6 key genes with important functions in alkaloids synthesis of C.chinensis.After treatment with diurnal temperature difference,the relative expression levels of key genes in the roots,stems and leaves of C.chinensis were higher than those in the control group,indicating that the diurnal temperature difference probably induce the expression of key genes.However,the expression of the key genes that catalyze the oxidation of tetrahydroxide under the water deficiency was significantly higher than that under the normal watering conditions,but after resuming watering,their expression levels decreased.The expression levels of the four key genes that catalyze the methylenedioxy bridge increased over time,but their expression levels were significantly lower than those of the control group after the water deficiency treatment,indicating that the lack of water would cause the expression level of those genes reduced.Diurnal temperature difference has a direct and specific induction effect on key genes,and the lack of water will increase the expression of key genes that catalyze the oxidation of tetrahydroxide,and decrease the expression of key genes that catalyze the methylenedioxy bridge.