Effects Of Environment And Genotype On Accumulation And Functions Of Bioactive Constituents In Cyclocarya Paliurus Leaves

In this thesis,we used Cyclocarya paliurus?Batal?Iljinskaja from both natural populations and indoor trials?light intensity and light quality;light quality and genotype?as the research material to explore the response mechanism of important bioactive substances accumulated in C.paliurus leaves to environmental factors and their variation of pharmacological activity,to provide theoretical basis and technical support for the directional cultivation of C.paliurus plantations.The main results are as follows:1.The ethanol extracts of C.paliurus from different populations were found abundant in phenolic acids,flavonoids and triterpenoids,and the major components were:3-O-caffeoylquinic acid(0.04¹.38 mg g^-1),quercetin-3-O-glucuronide(0.30².38 mg g^-1),and kaempferol-3-O-glucuronide(0.30².38 mg g^-1),etc.However,the aqueous extracts of C.paliurus were found abundant in polysaccharides(18.72⁵3.59 mg g^-1).2.There were significant differences among the antihyperglycemic and antihyperlipidemic effects of C.paliurus from different populations,and the effect of ethanol extracts was obviously better than that of aqueous extracts.The populations with better antihyperglycemic effect were characterized with higher contents of flavonoids,while those with better lipid lowering effect had higher contents of total triterpenoids,isoquercetin,cyclocaric acid B and oleanolic acid.Compared with diabetic group,the levels of liver and kidney indexes were significantly decreased in positive controls and treatments with C.paliurus extracts.3.The contents of water-soluble polysaccharides(18.72⁵3.59 mg g^-1)in leaves of C.paliurus from different populations and their antioxidant capacity varied significantly?P<0.05?,meanwhile,polysaccharides content and antioxidant activity were both positively correlated with mean annual precipitation.There was significant difference in phenolic contents(2.77⁷.89 mg g^-1)in leaves of C.paliurus from different populations,and the populations with higher contents were observed with significantly higher mean annual temperature and sunshine hours.The natural populations of C.paliurus studied had strong antioxidant activity.The antioxidant ability of C.paliurus was positively correlated with the contents of total phenolics and flavonoids,and the contribution of individual phenolics to the antioxidant ability was significantly different?P<0.05?.4.Light intensity,light quality and their interaction significantly affected the biomass accumulation,photosynthetic capacity,chlorophylls contents and their ratios in C.paliurus?P<0.05?.The C.paliurus seedlings treated with red light and blue light with higher light intensity showed higher values of seedling height and diameter,biomass accumulation,photosynthesis and chlorophyll contents than those treated with green light and purple light.Light intensity and its interaction with light quality significantly affected the accumulation of bioactive components in C.paliurus?P<0.05?.In general,red light treatment with higher light intensity was helpful to the accumulation of polysaccharides in leaves,while blue light treatment with medium and higher light intensity contributed to the accumulation of flavonoids and triterpenoids in leaves.5.Both primary growth and secondary metabolism of C.paliurus from different genotypes were changed by light quality treatment under medium light intensity,meanwhile,the responses of different genotypes to light quality were different.The plants showed a series of activities,including changes of morphological,anatomical structure,regulation of photosynthetic II activity,chemical components and protective enzyme systems,to adapt to changes of light environment.Compared with white light?WL?,the total biomass,photosynthetic capacity and chlorophyll contents of C.paliurus under other light treatments?blue light:BL;green light:GL;red light:RL?decreased significantly.GL and RL treatments showed a certain degree of photoinhibition and membrane lipid peroxidation.The total biomass,photosynthetic capacity,Fv/Fm of photosystem II and performance index of Anji seedlings were significantly higher than those of other genotypes?P<0.05?.6.The contents of bioactive components in C.paliurus and their yields from different genotypes were significantly affected by light quality treatment?P<0.05?.The polysaccharide content and yield under WL and RL treatments were significantly higher than those from BL and GL treatments.The yields of total phenolics and total flavonoids per plant were in consistent with their contents,with the highest values observed from GL and BL treatments.The highest values of total triterpenoid content and yield per plant were obtained under WL treatment.The total phenolic content and yield of C.paliurus from Jinzhongshan 6 were higher than that of other genotypes,while the contents and yields of polysaccharide and total triterpenoids in C.paliurus from Jinzhongshan 7 were higher than that of other genotypes.Results showed that there was no significant difference in the tissue localization of bioactive components in C.paliurus leaves after light quality and genotype treatments.In general,the accumulation patterns of polysaccharides,flavonoids and triterpenoids in the leaves of C.paliurus were similar,with the most observed in the epidermis,palisade tissue and phloem.7.Light quality and genotype significantly affected the enzymes activity of phenolic synthesis pathway and related gene expression,and significantly positive correlations between the activities of related enzymes and the contents of total phenolics,total flavonoids and total phenolic acid were observed?P<0.01?.The relative expression of PAL,4CL and CHS genes were the highest under GL treatment.Results showed that the synthesis of triterpenoids from C.paliurus leaves was dominated by both MVA and MEP pathway.8.Light environment and genotype affect the medicinal value of C.paliurus leaves,such as the antioxidant activity in vitro.WL treatment resulted the weakest antioxidant activity in vitro,while RL and GL treatments significantly increased the antioxidant capacity of C.paliurus leaves.Muchuan genotype had the highest antioxidant activity in vitro.