Arsenic, chromium and NaCl induced artemisinin biosynthesis in Artemisia annua L.: A valuable antimalarial plant

Effect of As(III), Cr(VI) and NaCl on plant growth, antioxidant enzymes, SOD, TBRAS, protein, cDNA amplification of key genes of artemisinin pathway and artemisinin biosynthesis have been investigated to explore the actual changes in total herb and artemisinin yield in a crop cycle of Artemisia annua. Enhanced TSARS and SOD activity (4 U mg(-1)), decreased catalase activity and total cholorophyll content were observed under metal(loid) and NaCI stress. Accumulation of As (III; gg mg(-1) DW) was higher in roots (10.75 +/- 0.00) than shoot (0.43 +/- 0.00) at 10 fig ml(-1). While Cr(VI; pig ml(-1) DW) accumulated more in shoots (37 +/- 9.6, 41.1 +/- 7.2 and 52.71 +/- 19.6). cDNA template of these treated plants along with control were amplified with HMGR, ADS and CYP71AV1 genes (artemisinin biosynthetic pathway genes); showed very low expression with Cr(VI) while As(III) (5 and 7.5 gg ml(-1)) showed higher expression than control. The results obtained from this study suggest that A. annua can grow well with favoring artemisinin biosynthesis with treatment of As(III) 5, 7.5 lig ml(-1) and NaCI, while 10 gg ml(-1) As(III) and all doses of Cr(VI) affect artemisinin synthesis. Finally some evidence also suggests that As(III), Cr(VI) and NaCl induces stress affects on total herb yield of plant. (C) 2013 Elsevier Inc. All rights reserved.