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With the development of urbanization and industrialization, soils have become increasingly polluted by heavy metals. Phytoremediation, an emerging cost-effective, nonintrusive, and aesthetically pleasing technology that uses the remarkable ability of plants to concentrate elements, can be potentially used to remediate metal-contaminated sites. In this research, two processes of phytoremediation (phytoextraction and phytostabilization) were surveyed in some plant species around an industrial town in the Hamedan Province in the central-western part of Iran. To this purpose, shoots and roots of the seven plant species and the associated soil samples were collected and analyzed by measuring Pb, Fe, Mn, Cu, and Zn concentrations using ICP-AES and then calculating the biological absorption coefficient, bioconcentration factor, and translocation factor parameters for each element. The obtained results showed that among the collected plants, Salsola soda is the most effective species for phytoextraction and phytostabilization and Cirsium arvense has the potential for phytostabilization of the measured heavy metals.

Excessive amounts of heavy metals adversely affect plant growth and development. Also, the presence of elevated levels of heavy metal ions triggers a wide range of cellular responses including changes in gene expression and synthesis of metal-detoxifying peptides. The overall objective of this research was to elucidate some microscopic effects of heavy metals on the formation, development, and structure of ovule and seed storage proteins in Chenopodium botrys L. To achieve this purpose, the surrounding area of Hame-Kasi iron and copper mine (Hamedan, Iran) was chosen as a polluted area where the amount of some heavy metals was several times higher than the natural soils. Flowers and young pods were removed from nonpolluted and polluted plants, fixed in FAA 70 and subjected to developmental studies. Our results showed that heavy metals can cause some abnormalities during the ovule developmental process. Decreasing the size of embryo sac, quick growth of inner integument, quick degradation of embryonic sac cells, accumulation of dark particles, irregularity, and even blockage of the nuclear envelope formation and increasing of embryonic sac cytoplasm concentration were the effects of heavy metals. Reduction of ovule number was also seen in the plants collected from polluted area. For protein studies, mature seeds were harvested from nonpolluted and polluted plants at the same time. Seed storage proteins (water soluble ones) were extracted and studied by sodium dodecyl sulfate-polyacrylamide gel electrophoresis after being prepared. The results revealed that there were no significant differences between seed protein bands of polluted and nonpolluted samples, but the quantity of protein bands was different, and there was a slight quantitative increase of bands with molecular mass of 35 and 15 kD and decrease of a band with molecular mass of 17 kD in the plants collected from the mine area.

As a result of human activities such as mining, metal pollution has become one of the most serious environmental problems today. Phytoremediation, an emerging cost-effective, non-intrusive, and aesthetically pleasing technology that uses the remarkable ability of plants to concentrate elements can be potentially used to remediate metal-contaminated sites. The aim of this work was to assess the extent of metal accumulation by plants found in a mining area in Hamedan province with the ultimate goal of finding suitable plants for phytoextraction and phytostabilization (two processes of phytoremediation). To this purpose, shoots and roots of the 12 plant species and the associated soil samples were collected and analyzed by measurement of total concentrations of some elements (Fe, Mn, Zn, and Cu) using atomic absorption spectrophotometer and then biological absorption coefficient, bioconcentration factor, and translocation factor parameters calculated for each element. Our results showed that none of the plants were suitable for phytoextraction and phytostabilization of Fe, Zn, and Cu, while Chenopodium botrys, Stipa barbata, Cousinia bijarensis, Scariola orientalis, Chondrila juncea, and Verbascum speciosum, with a high biological absorption coefficient for Mn, were suitable for phytoextraction of Mn, and C. bijarensis, C. juncea, V. speciosum, S. orientalis, C. botrys, and S. barbata, with a high bioconcentration factor and low translocation factor for Mn, had the potential for the phytostabilization of this element.

Heavy metals are some of the most important environmental pollutants. Excessive amounts of heavy metals adversely affect plant growth and development. Also, the presence of elevated levels of heavy metal ions triggers a wide range of cellular responses including changes in gene expression and synthesis of metal-detoxifying peptides. The overall objective of this research was to elucidate some microscopic effects of heavy metals on the formation, development, and structure of pollen, ovule, and embryo and also root proteins in Reseda lutea L. For this purpose, the vicinity of Ahangaran lead-zinc mine (Hamedan, Iran) was chosen as a polluted area where amount of some heavy metals was several times higher than the natural soils. Flowers and young buds were collected from non-polluted and polluted plants, fixed in FAA(70), and studied during developmental stages by light microscopy. The results showed that heavy metals can cause some abnormalities during the pollen and ovule developmental process. The number of pollen grains was decreased, and their shape was changed. Increasing in thickness of the callosic wall and stabilizing of tapetum layer were observed in polluted plants. Asymmetrical formation of ovular integuments, degradation of egg apparatus, irregular formation of embryo sac, considerable vacuolation of embryonic cells, and degeneration of embryo in the late stage of heart-shaped embryo are the results of heavy metal pollution. For protein studies, young roots were harvested from plants exposed to pollution and non-exposed to pollution at the same time. Root proteins were extracted and studied by electrophoresis. The results revealed that some new proteins were synthesized in polluted samples that probably elevate plant tolerance to heavy metals.

Excessive amounts of heavy metals adversely affect plant growth and development. Whereas some regions naturally contain high levels of heavy metals, anthropogenic release of heavy metals into the environment continuously increases soil contamination. Preliminary studies have shown that Chenopodium botrys can grow in some heavy metal contaminated soils and is a high accumulator plant species for Cu and moderately accumulator plant species for Fe, Mn, and Zn, thus, was considered as an important species in this study. Based on that, in this species, we studied the individual effects of heavy metals on the formation, development, and structure of anther and pollen. To achieve this purpose, surrounding area of Hame-Kasi iron and copper mine (Hamedan, Iran) was chosen as a polluted area where the amount of some heavy metals was several times higher than the natural soils. Flowers and young pods were removed from non-polluted and polluted plants, fixed in FAA 70, and subjected to developmental studies. Analysis of anther development in plants from contaminated sites showed general similarities in the pattern of pollen formation with those from non-polluted ones, but also deviation from typical form of major stages of anther and pollen development was seen in plants from polluted ones. Stabilizing of tapetum layer, increasing in tapetum layer numbers, thickening callose wall in the microspore mother cell stage, changing the anther shape, and decreasing the size of anther were the effects of heavy metals. Reduction of pollen number was also seen in the plants collected from polluted area.