title: Nutrient deficiency in the production of artemisinin, dihydroartemisinic acid, and artemisinic acid in Artemisia annua L.
abstract: Artemisia annua became a valuable agricultural crop after the World Health Organization recommended artemisinin as a component of ACT (artemisinin-combination based therapies) for malaria in 2001. A cloned, greenhouse-grown, A. annua (Artemis) subjected to an acidic soil and macronutrient deficit was evaluated for artemisinin production. Lack of lime (L) and macronutrients (N, P, and K) reduced leaf biomass accumulation. When L was provided (pH 5.1), the highest average leaf biomass was achieved with the "complete" (+N, +P, +K, and +L) treatment (70.3 g/plant), and the least biomass was achieved with the untreated (-N, -P, -K, and -L) treatment (6.18 g/plant). The nutrient least required for biomass accumulation per plant (g) was K (49.0 g), followed by P (36.5 g) and N (14.3 g). The artemisinin concentration (g/100 g) was significantly higher (75.5%) in -K plants when compared to plants under the complete treatment (1.62 vs 0.93%). Although the artemisinin total yield (g/plant) was 21% higher in -K plants, it was not significantly different from plants under the complete treatment (0.80 vs 0.66 g/plant). There were no marked treatment effects for concentration (g/100 g) or yield (g/plant) of both dihydroartemisinic acid and artemisinic acid, although higher levels were achieved in plants under the complete or -K treatments. There was a positive and significant correlation between artemisinin and both artemisinic acid and dihydroartemisin acid, in g/100 g and g/plant. This is the first report where potassium deficiency significantly increases the concentration (g/100 g) of artemisinin. Thus, under a mild potassium deficiency, A. annua farmers could achieve similar gains in artemisinin/ha, while saving on potassium fertilization, increasing the profitability of artemisinin production.
authors.affiliation: Appalachian Farming Systems Research Center, Agricultural Research Service, U.S. Department of Agriculture, 1224 Airport Road, Beaver, West Virginia 25813, USA. Jorge.Ferreira@ars.usda.gov
authors.forename: Jorge F S
authors.initials: JF
authors.lastname: Ferreira
mesh_terms: D031172:Artemisia annua / Q000737:chemistry / Q000254:growth & development* / Q000378:metabolism*; D037621:Artemisinins / Q000032:analysis / Q000378:metabolism*; D005306:Fertilization; D011188:Potassium / Q000032:analysis; D012717:Sesquiterpenes / Q000032:analysis / Q000378:metabolism*; D012987:Soil / Q000032:analysis*
chemical_list: D037621:Artemisinins; D012717:Sesquiterpenes; D012987:Soil; C520462:dihydroartemisinic acid; C047721:artemisic acid; C031327:artemisinin; D011188:Potassium