光照影响红曲霉桔霉素代谢机制的研究

Effect of light on citrinin metabolism mechanism of Monascus

利用高效液相色谱(HPLC)法研究了红光、蓝光、黑暗条件下红曲霉的桔霉素产量,利用实时荧光定量聚合酶链式反应(RT-FQPCR)检测了桔霉素相关合成基因簇(ctnA、pksCT、orf7基因)、全局性转录因子(LaeA、VeA基因)及pka基因的表达量,研究光照对红曲霉桔霉素代谢机制的影响。研究发现,与黑暗条件相比,蓝光条件下菌体生物量降低15.85%,桔霉素产量升高30.40%;红光条件下生物量无显著差异(P>0.05),桔霉素产量降低35.26%。蓝光促进ctnA和pksCT基因的表达、抑制orf7基因的表达,红光抑制ctnA和pksCT基因的表达、促进orf7基因的表达。蓝光抑制LaeA、VeA和pka基因的表达,红光促进LaeA、VeA和pka基因的表达。结果表明,光照通过调控LaeA、VeA和pka基因的表达量进行信号传递,调控桔霉素基因簇重要的调控因子ctnA和orf7,改变桔霉素合成基因pksCT表达量,进而实现对桔霉素产量的调控作用。

The yield of citrinin produced by Monascus under red light,blue light and dark conditions was studied by HPLC.The expression quantity of citrinin-related synthetic gene clusters(ctnA,pksCT,orf7),global transcription factor(LaeA,VeA)and pka was detected by real-time fluorescent quantitative polymerase chain reaction(RT-FQPCR)to study the effect of light on citrinin metabolism mechanism by Monascus.The study showed that compared with the dark conditions,the biomass under blue light decreased by 15.85%,and the yield of citrinin increased 30.40%;the red light had no significant effect on biomass(P>0.05),and the yield of citrinin under red light decreased by 35.26%.The blue light promoted the expression of ctnA and pksCT genes,and inhibited the expression of orf7 gene.The red light inhibited the expression of ctnA and pksCT genes,and promoted the expression of orf7 gene.The blue light inhibited the expression of LaeA,VeA and pka genes,and red light promoted the expression of LaeA,VeA and pka genes.The results showed that the light could transmit signals by regulating the expression quantity of LaeA,VeA and pka genes,regulating the important regulatory factors ctnA and orf7 of citrinin biosynthetic gene clusters,and changed the expression quantity of pksCT gene,to achieve the regulation of citrinin yield.