Response Of Secondary Metabolism Of Baicalin In Callus Of Scutellaria Baicalensis Georgi To Temperature Change

Scutellaria baicalensis Georgi is a perennial herb of Labiatae.Its dried root has many medicinal functions,such as clearing heat and detoxification,hemostasis,anti-inflammatory and antibacterial.In this paper,callus induction was selected as the best explant material of annual potted S.baicalensis L,and expanded to stable genetic system.After callus growth to the maximum biomass,the callus was treated by changing temperature,the temperature-variable treatment was carried out after the biomass reached the maximum value,and different temperature conditions were discussed.The changes of baicalin content,protective enzyme activity,key enzyme activity and key enzyme gene expression in callus of S.baicalensis were studied to explain the response process of callus to environmental signal.The molecular ecological regulation mechanism of temperature changes on the accumulation and accumulation of active ingredients in S.baicalensis Georgi,and to provide a scientific theoretical basis for the quality stability and controllability of S.baicalensis.The main findings are as follows:(1)The changes of temperature had a significant effect on the baicalin content in the callus of S.baicalensis,and there are differences in the performance of baicalin content at different temperatures at the same temperature.in different treatment time at the same temperature.The content was treated at 20 °C for 4d to reach a maximum of 2.64%.30 °C treatment played a certain role in promoting the synthesis of baicalin.Inhibition of baicalin synthesis was inhibited below 20°C,and the lower the temperature,the more pronounced the inhibitory effect.(2)The changes of temperature had a significant effect on the activities of antioxidant enzymes(SOD,POD,CAT)in the callus of S.baicalensis.After the environmental temperature changes,the activity of the three protective enzymes rapidly increases,and the synergistic action together removes excess oxygen free radicals and resists oxidative damage.With the prolongation of treatment time,the activities of the three protective enzymes showed different degrees of attenuation.(3)The changes of temperature had a significant effect on the activities of key enzymes(PAL,C4 H,4CL,CHS,CHI)of the baicalin biosynthesis pathway.20 °C enhanced the activity of PAL,C4 H and CHS enzymes.Under 15 °C and 30 °C treatment,4CL and CHI activity reached the strongest.In the interval of 10°C-20°C,the key enzymes C4 H,CHS and CHI play a role in promoting the synthesis and accumulation of baicalin.(4)The changes of temperature had a significant effect on the key enzyme genes(PAL,C4 H,4CL,CHS,CHI)of the baicalin biosynthetic pathway.The PAL and CHI genes were most actively treated at 10°C.The relative expression of 4CL and CHS genes was higher at 30°C and the C4 H gene expression was up-regulated at 20°C.In the interval of 15°C-30°C,the key enzyme genes PAL,C4 H,CHS and CHI co-direct the biosynthesis of baicalin.