Siddiqui Fauzia, Tandon P K, Srivastava Sudhakar
Department of Botany, University of Lucknow, Lucknow, 226007 U.P. India.
Institute of Environment & Sustainable Development, Banaras Hindu University, Varanasi, 221005 U.P. India.
Physiol Mol Biol Plants. 2015 Jan;21(1):61-9. doi: 10.1007/s12298-014-0278-7. Epub 2015 Jan 8.
Withania somnifera has been an important herb in the Ayurvedic and indigenous medical systems for centuries in India. However, these grow as weeds mostly in the wastelands, which receive contaminated water from municipal and industrial sources. In the present investigation, plants of Withania somnifera were exposed to various concentrations of arsenate (AsV) and arsenite (AsIII) (0, 10, 25, 50, 100 μM) for 10 days and analysed for accumulation of arsenic (As) and physiological and biochemical changes. Plants showed more As accumulation upon exposure to AsIII (320 μg g(-1) DW in roots and 161 μg g(-1) DW in leaves) than to AsV (173 μg g(-1) DW in roots and 100 μg g(-1) DW in leaves) after 10 days of treatment. Consequently, AsIII exposure caused more toxicity to plants as compared to that AsV, as evaluated in terms of the level of photosynthetic pigments and oxidative stress parameters (superoxide, hydrogen peroxide and lipid peroxidation), particularly at higher concentrations and on longer durations. Plants could tolerate low concentrations (variable for AsIII and AsV) until longer durations (10 days) and high concentrations for shorter durations (1-5 days) through increase in antioxidant enzymes and by augmented synthesis of thiols. In conclusion, As tolerance potential of Withania plants on one hand advocates its prospective use for remediation under proper supervision and on the other demonstrates possible threat of As entry into humans due to medicinal uses.
数世纪以来，印度阿育吠陀医学和本土医疗体系中，印度人参一直是一种重要的草药。然而，这些植物大多生长在荒地的杂草丛中，而这些荒地接收来自市政和工业源的受污染水。在本研究中，将印度人参植株暴露于不同浓度的砷酸盐（AsV）和亚砷酸盐（AsIII）（0、10、25、50、100 μM）中10天，并分析其砷（As）的积累以及生理和生化变化。处理10天后，与暴露于AsV（根中173 μg g(-1) DW，叶中100 μg g(-1) DW）相比，植株暴露于AsIII时积累的As更多（根中320 μg g(-1) DW，叶中161 μg g(-1) DW）。因此，根据光合色素水平和氧化应激参数（超氧化物、过氧化氢和脂质过氧化）评估，与AsV相比，AsIII对植株造成的毒性更大，尤其是在较高浓度和较长处理时间时。植株可以通过增加抗氧化酶和增强硫醇的合成来耐受低浓度（AsIII和AsV的耐受浓度不同）较长时间（10天）以及高浓度较短时间（1 - 5天）。总之，印度人参植株的耐砷潜力一方面表明其在适当监管下用于修复的潜在用途，另一方面也显示出由于药用而导致砷进入人体的潜在威胁。
