a b s t r a c t
The effects of arsenic stress on the production of low molecular weight thiols (LMWT), glutathione
S-transferase activity (GST) and sulfur metabolism of mesquite plant (Prosopis sp.) were examined in
hydroponic culture at different arsenic [As(III) and (V)] concentrations. The production of LMWT was
dependent on As speciation and concentration in the growth medium. The roots of As(III) treated plants
produced significantly higher LMWT levels than As(V) treated roots at the same concentration of
As applied. In leaves, the thiols content increased with increasing As(III) and (V) concentrations in the
medium. Hypersensitivity of the plant to high As concentrations was observed by a significant decrease
of LMWT produced in the roots at 50 mg/L treatment in both As(III) and (V) treatments. Sulfur was
translocated from roots and accumulated mainly in the shoots. In response to As-induced phytotoxicity,
the plants slightly increased the sulfur content in the roots at the highest As treatment. Compared with
As(V)-treated plants, As(III)-treated roots and leaves showed significantly higher GST activity. The roots
of both As(III) and (V) treated plants showed an initial increase in GST at low As concentration (5 mg/L),
followed by significant inhibition up to 50 mg/L. The leaves had the highest GST activity, an indication of
the ability of the plant to detoxify As in the leaves than in the roots. The correlation between LMWT
content, S content and GST activity may be an indication these parameters may be used as biomarkers of
As stress in mesquite.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:tut/oai:encore.tut.ac.za:d1001709 |
| Date | 02 July 2009 |
| Creators | Mokgalaka-Matlala, NS, Flores-Tavizon, E, Castillo-Michel, H, Peralta-Vdea, JR, Gardea-Torresdey, JL |
| Publisher | Elsevier |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | |
| Rights | c 2009 Elsevier Masson SAS |
| Relation | Plant Physiology and Biochemistry |
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