Accumulation Of Anti-malarial Components And Soil Characteristics Of Artemisia Annua L.

Malaria,one of the three major death diseases,has threatened human life with rapid morbidity,high mortality and difficult prevention and cure for a long time.Until the 1970 s,Antimalarial artemisinin,which was extracted from Artemisia annua L.by Chinese scientist Tu Yoyo,has become the first choice drug approved for the treatment of malaria by the World Health Organization(WHO).Although the scientists obtained artemisinin from different ways(such as chemical synthesis,etc.),synthetic artemisinin has not been applied due to the complicated synthesis technology and high cost.In addition,the accumulation of artemisinin(AOA)in A.annua in different habitats was significantly different(0.01 ~ 1.5%),while the content > 0.6%has only the value of industrial extraction.Thus,increasing the artemisinin content of A.annua is most important way to obtain artemisinin antimalarial drugs.However,A.annua has hitherto been the only raw material plant for obtaining artemisinin.AOA is essentially a biosynthesis process,which possesses one or more synthetic precursor and plays an important role in AOA.It is reported that phenolics have synergistic antimalarial effects with artemisinin.The accumulation of these components(commonly known as antimalarial related components,ARCs)is closely related to environmental conditions,and soil is an important factor.Therefore,it is of great theoretical significance to carry out studies on the accumulation of ARCs and soil characteristics of A.annua.In this paper,we studied the relationship between the accumulation of ARCs and soil characteristics by analyzing the accumulation of ARCs and the soil characteristics of A.Annua.The obtained results were as following:1.Accumulation of ARCs in A.annuaThe contents of artemisinin,artemisinic acid,scopoletin,shrysosplenpl-D,shrysospenetin and total polyphenols of A.annua were different at different sites among the research areas.The variation trend of contents for artemisinin and artemisinic acid was consistent.And the content of artemisinin was higher than that of artemisinic acid,which may produce synergistic antimalarial effect between them.And in terms of the contents of phenolics of A.annua,the sequence of scopoletin > shrysospenetin > shrysosplenpl-D was found.And the content of scopoletin was greater than the sum of the content of shrysospenetin and shrysosplenpl-D.The variation trend of the total polyphenol concentration was similar to that of shrysosplenpl-D.Thses results illustrated that scopoletin was widely distributed in A.annua.2.Soil characteristics of A.annua growthThe contents of organic matter,nitrogen,phosphorus and potassium,and the urease,invertase and phosphatase activities were different at different sites because of the various types of soil.In general,the contents of soil organic matter,available nitrogen,total phosphorus,total potassium,available potassium,invertase activity,total PLFAs of microbial,total bacteria,G+ bacteria,Gbacteria of A.annua in rhizosphere soil were higher than those of A.annua non-rhizosphere soil.There was no significant difference among total nitrogen,available phosphorus contents,urease,phosphatase activity,fungi,actinomycetes and nematodes in rhizosphere soil and nonrhizosphere soil.On the contrary,the value of p H in rhizosphere soil was significantly lower than that of p H in non-rhizosphere soil,which might be affected by the rhizosphere exudates of A.annua or microbial exudates of soil.These results obtained illustrated that there is interaction between A.annua and the rhizosphere soil.3.Correlation between ARCs and soil characteristics of A.annuaThe results from correlation analysis between the A.annua ARCs and soil factors showed that the scopoletin were significantly or extremely significantly positive related to available phosphorus and G-in rhizosphere soils(p < 0.05 or p < 0.01),while significantly negative related to alkaline nitrogen in rhizosphere soils(p < 0.05).The shrysosplenpl-D were significantly or extremely significantly positive related to the total potassium,G+,fungi and actinomycetes in rhizosphere soils(p < 0.05 or p < 0.01).The chrysosplenetin were significantly or extremely significantly positive related to the available phosphorus,total potassium,available potassium,total PLFAs of microbial,bacteria and actinomycetes in rhizosphere soils(p < 0.05 or p < 0.01).The artemisinin were extremely significantly negative related to the alkaline nitrogen and invertase in rhizosphere soils(p < 0.01),and extremely significantly positive related to G+ in rhizosphere soils(p < 0.01).The artemisinic acid were extremely significantly negative related to alkaline nitrogen,invertase in rhizosphere soil(p < 0.05 or p < 0.01),and extremely significantly positive related to p H and G+ in rhizosphere soils(p < 0.01).The total polyphenol were extremely significantly positive related to the G+ in rhizosphere soils(p < 0.01).