فیزیولوژی محیطی گیاهی (Nov 2007)
The effects of lead pollution on the growth parameters, protein content, sugars, and anatomical structure in Medicago sativa L.
Abstract
In this investigation, the effects of various concentrations of Pb(NO3)2 (0.25–0.5–1–2mM) on the growth parameters in Medicago sativa L. were studied. The Treatment period was 20 days and the end of this period, the length, dry weight, and fresh weight of roots and shoots, leaves area, microscopically observation, accumulation of lead in roots and shoots, determination of soluble and insoluble sugars, total proteins and profile of proteins by SDS-PAGE, measured and studied. The statistical studies were carried out by SPSS software and variance analysis (ANOVA) and Duncan test. The results showed that lead toxicity decreased significantly roots and shoots length, leaves area, dry and fresh weight and in the high concentration of Pb+2, lignin biosynthesis and fiber were increased. Analyzing of lead content in the roots and shoots by atomic absorption indicated that, the lead absorption excess by increasing level of lead in treatments. When the concentration of lead increased, the amount of soluble sugars in shoots and roots were decreased whereas insoluble sugars in shoots were increased but in roots were decreased. By increasing lead in treatment both in shoots and roots, the total protein increased. The profile of proteins by SDS-PAGE showed some changes as compared with control plants. This research indicated that the Medicago sativa L. is a heavy metal tolerant plant and absorbed high level of lead from soil and accumulated in roots and shoots tissues.
