1. Increasing Sulfur Supply Enhances Tolerance to Arsenic and its Accumulation in Hydrilla verticillata (L.f.) Royle.
- Author
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SRIVASTAVA, SUDHAKAR and D'SOUZA, S. F.
- Subjects
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HYDRILLA , *BIOACCUMULATION , *EFFECT of arsenic on plants , *OXIDATIVE stress , *EFFECT of sulfur on plants , *PLANT metabolism , *TOXICOLOGICAL chemistry - Abstract
The present study was aimed to analyze the effects of variable S supply on arsenic (As) accumulation potential of Hydrilla verticillata (Lf.) Royle. Plants were exposed to either arsenate (AsV; 50 μM) or arsenite (AsIII; 5 μM) for 4 h and 1 day while S supply was varied as deficient (2 μM, -S), normal (1 mM, +S) and excess (2 mM, +HS). The level of As accumulation (μg g-1 dw) after 1 day was about 2-fold higher upon exposure to either AoV (30) or AsIII (50) in +HS plants than that being in +S(12 and 24) and -S (14 and 26) plants. The +HS plants showed a significant stimulation of the thiol metabolism upon As exposure. Besides, they did not experience significant toxicity, measured in terms of malondialdehyde accumulation; an indicator of oxidative stress. By contrast, -S plants suffered from oxidative stress probably due to negative impact to thiol metabolism. Variable S supply also modulated the activity of enzymes of glycine and serine biosynthesis indicating an interconnection between S and N metabolism. In conclusion, an improved supply of S to plants was found to augment their ability for As accumulation through stimulated thiol metabolism. [ABSTRACT FROM AUTHOR]
- Published
- 2009
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