Effects of Aluminium Exposures on Growth, Photosynthetic Efficiency, Lipid Peroxidation, Antioxidant Enzymes and Artemisinin Content of Artemisia annua L.
Acid soils are widely distributed at a global scale; under acidic conditions, the solubility of aluminium (Al) increases and the elevated concentration of toxic Al3+ in soil solution seriously limits crop production. There is no information on the effects of aluminium (Al) on Artemisia annua L., which is a most important antimalarial plant in the recent time being artemisinin; responsible for its antimalarial activity. In this report, we describe the effects of Al contamination on growth, photosynthetic efficiency, membrane damage, antioxidant enzyme activities and changes in artemisinin content in A. annua. Al addition to the soil medium significantly reduced the yield and growth of the plants. Lower values of net photosynthetic rate, stomatal conductance, internal CO2 and total chlorophyll content were observed as a result of different Al concentrations applied. The activities of nitrate reductase (NR) and carbonic anhydrase (CA) were also found to be hampered by Al exposure to the plants. Al enhanced lipid peroxidation rate (TBRAS content) and activated the activities of catalase (CAT), peroxidase (POX) and superoxide dismutase (SOD) enzymes in the treated plants. The elicitation in the endogenous ROS levels, due to the Al treatments, was also noticed in the present study. Furthermore, enhanced artemisinin content and yield was obtained at 0.10mM concentration of soil applied Al. Our study provides evidence that excess Al in soil hamper the growth and yield, slow down the activities of NR and CA, induce lipid peroxidation and antioxidant enzymes but a low level of Al-toxicity can induce artemisinin content in A. annua plants.Key words: Aluminium (Al); Artemisia annua L.; Artemisinin; Lipid peroxidation; Reactive oxygen species (ROS)Tariq Aftab et al. Effects of Aluminium Exposures on Growth, Photosynthetic Efficiency, Lipid Peroxidation, Antioxidant Enzymes and Artemisinin Content of Artemisia annua L. J Phytol 2/8(2010) 23-37
