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Bioaccumulation and physiological effects of mercury in Sesbania drummondii [An article from: Chemosphere]
Book Details
PublisherElsevier
ISBN / ASINB000P6OQ1S
ISBN-13978B000P6OQ13
AvailabilityAvailable for download now
Sales Rank9,645,241
MarketplaceUnited States 🇺🇸
Description
This digital document is a journal article from Chemosphere, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.
Description:
The accumulation of mercury and its effect on growth, photosynthesis and antioxidative responses were studied in Sesbania drummondii seedlings. Mercury concentration in shoots as well as in the roots increased with increasing Hg concentrations in the growth solution. The accumulation of Hg was more in roots than shoots. At 100mgl^-^1 Hg concentration, shoots accumulated 998mgHgkg^-^1 dry weight (dw) while roots accumulated 41403mgHgkg^-^1dw. Seedlings growth was not significantly affected at lower concentrations of Hg. A concentration of 100mgl^-^1 Hg inhibited growth by 36.8%, with respect to control. Photosynthetic activity was assessed by measuring chlorophyll a fluorescence by determination of F"v/F"m and F"v/F"o values. Photosynthetic integrity was not affected up to 50mgl^-^1 Hg concentration, however, concentrations higher than 50mgl^-^1 affected photosynthetic integrity. Sesbania responded to Hg induced oxidative stress by modulating non-enzymatic antioxidants [glutathione (GSH) and non-protein thiols (NPSH)] and enzymatic antioxidants: superoxide dismutase (SOD), ascorbate peroxidase (APX) and glutathione reductase (GR). Glutathione content and GSH/GSSG ratio increased up to a concentration of 50mgl^-^1 while slight down at 100mgl^-^1 Hg. The content of NPSH significantly increased with increasing Hg concentrations in the growth medium. The activities of antioxidative enzymes, SOD, APX and GR followed the same trends as antioxidants first increased up to a concentration of 50mgl^-^1 Hg and then slight decreased. The results of present study suggest that Sesbania plants were able to accumulate and tolerate Hg induced stress using an effective antioxidative defense mechanisms.
Description:
The accumulation of mercury and its effect on growth, photosynthesis and antioxidative responses were studied in Sesbania drummondii seedlings. Mercury concentration in shoots as well as in the roots increased with increasing Hg concentrations in the growth solution. The accumulation of Hg was more in roots than shoots. At 100mgl^-^1 Hg concentration, shoots accumulated 998mgHgkg^-^1 dry weight (dw) while roots accumulated 41403mgHgkg^-^1dw. Seedlings growth was not significantly affected at lower concentrations of Hg. A concentration of 100mgl^-^1 Hg inhibited growth by 36.8%, with respect to control. Photosynthetic activity was assessed by measuring chlorophyll a fluorescence by determination of F"v/F"m and F"v/F"o values. Photosynthetic integrity was not affected up to 50mgl^-^1 Hg concentration, however, concentrations higher than 50mgl^-^1 affected photosynthetic integrity. Sesbania responded to Hg induced oxidative stress by modulating non-enzymatic antioxidants [glutathione (GSH) and non-protein thiols (NPSH)] and enzymatic antioxidants: superoxide dismutase (SOD), ascorbate peroxidase (APX) and glutathione reductase (GR). Glutathione content and GSH/GSSG ratio increased up to a concentration of 50mgl^-^1 while slight down at 100mgl^-^1 Hg. The content of NPSH significantly increased with increasing Hg concentrations in the growth medium. The activities of antioxidative enzymes, SOD, APX and GR followed the same trends as antioxidants first increased up to a concentration of 50mgl^-^1 Hg and then slight decreased. The results of present study suggest that Sesbania plants were able to accumulate and tolerate Hg induced stress using an effective antioxidative defense mechanisms.
