| Abstract |
Lead (Pb) and cadmium (Cd) contamination of soils pose significant problems for successful seed germination and establishment. We compared effects of subjecting wheat seeds either to a magnetic field (MF: 0-800 millitesla) or laser radiation (LR: 0-8 min at 20 mW/mm(2)) on wheat seed germination and on physiology and growth of young seedlings exposed to these two heavy metals as seeds and as 2-day-old seedlings. Intermediate levels of either MF or LR increased germination. In seeds untreated by MF or LR, exposure to Cd and Pb resulted in: significant increases in the concentrations of malondialdehyde ([MDA]) and superoxide anion radical ([O-2(-)]), and in the conductivity of electrolyte leakage (CEL); significant decreases in catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GR) activity; a significant decrease in glutathione concentration ([GSH]); and a significant decrease in shoot biomass relative to seeds exposed to these heavy metals following MF or LR treatments. Although both MF and LR ameliorated physiological effects of Cd and Pb exposure on young seedlings, only LR decreased Cd and Pb concentrations in the wheat shoot itself. Our results suggest that in agricultural sites contaminated by these two heavy metals, that LR could improve production and counter heavy metals accumulation. |
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