فهرست مطالب سیدمجید قادریان

Application of non-bio-stimulants is one of solutions to quantitative and qualitative changes in secondary metabolites of medicinal plants. Cadmium in plant reduces photosynthesis and respiration, decrease the metabolism of carbohydrates, causes cholorosis and decreases growth. The aim of the present study was to investigate the effect of cadmium concentrations on photosynthetic pigments, anthocyanin, proline, total soluble sugars, reducing sugars and atropine production in Datura stramonium L. The plants were cultured in perlite contained pots. Then plants were treated with different concentrations of Cd (0,1, 5,15 and 50 mg/L) for 2 weeks to measure physiological parameters and for 12 weeks to determine the amount of atropine. With increasing Cd concentration in solution media and photosynthetic pigments were significantly decrease. Also, the results indicated that the amount of anthocyanin, soluble and reduction carbohydrate and proline were significantly increased in most treatments up to 62/7%, 40/5%, 31/5%, 56/7%, respectively. Cadmium also increased the amount of atropine. The cadmium as a non-biological stress leads to increased plant defense mechanisms, including carbohydrate and proline and secondary metabolites of anthocyanin photosynthetic pigment and tropane alkaloids (atropine).

Plants grown in serpentine soils, in addition to heavy metals which their indicators is nickel (Ni) are encountered with a lot of edaphically stress such as drought stress. At the present study, we investigated the effect of pretreatment Ni and PEG-simulated drought stress on some physiological parameters and Ni accumulation of the serpintine plant, Cleome heratensis and related non-serpertine plant, Cleome foliolosa. After 75 days, half number of vessels with grown plants in hydroponic condition, received 20 µM Ni for 7 days, and then plants ± Ni were exposed to drought stress which simulated by PEG in three levels (0, -0.3, or −0.9MPa ) for 7 days. Results showed that serpentine plant populations were pretreated with Ni, shoot to root ratio significantly decreased and relative water content improved and these plants accumulate most of Ni in the root and with drought stress, accumulation Ni in the root increased and translocation it to shoot reduced, Serpentine plant in the highest level of water stress and total phenol amount was enhanced which agreement Phenyle alanin ammonia lyase (PAL) activity in the highest drought stress in C. heratensis, but deleterious effect on same parameters in C. foliolosa. Thus, it can be suggested that serpentine plants use nickel to increase drought resistance which represent the genotypic dependence of serpentine plants to nickel in order to improve drought stress resistance.

Serpentine soils are dry and contain rather high levels of nickel (Ni).To obtain a better understanding of drought tolerance by Ni in serpentine plants, a hydroponic trial was designed to compare the effects of Ni on growth factors, Ni uptake or translocation and some physiological parameters in the serpentine plant, Fortuynia garcinii (Burm.f.), under PEG simulated drought stress (3 levels). After 45 days, half number of vessels received 10 µM Ni for 8 days, and then plants ± Ni were exposed to drought stress for 8 days. The result indicating Ni treatment improved only slightly RWC, and Ni accumulation of root was consistently higher than shoot. The main reason for this action related to low translocation factors for this metal that showing this plant was more tolerant to plant-internal Ni. Photosynthetic pigments increased under drought stress treatments, but the treatments with Ni were consistently lower in compare same treatments without Ni in this serpentine plant. Phenolic compounds, water soluble carbohydrate, Glycine betaine and proline were also increased by Ni application under PEG simulated drought stress indicating that Ni improved the osmotic adjustment ability and enhance the antioxidant capacity. It is hypothesized that Ni could improve the drought tolerance of the serpentine plant by enhancing water utilization capability, osmotic adjustment and the abilities of antioxidative defense.

Antimony is a non-essential element for organisms. It has different toxic effects on organisms, especially on plants. However, some plants are able to counteract the toxic effects of antimony, uptake and accumulate it in their tissues. Tanacetum polycephalum is one of these plants. In this study, we collected plant samples from antimony polluted soils of Moghanlo mining area in Zanjan province, then analyzed samples in laboratory. The results showed that the highest amount of antimony in collected plants were 127.8 mg/KgDW in aerial parts. Also results of our experiment showed that increasing antimony concentration in the nutrient solution, decreased root and shoot dry weight and the decrease was more obvious in roots. Antimony accumulation in roots and shoots increased with increasing antimony concentration in treatments. In antimony concentration of 100 mg/L, antimony content in shoots was 1697.7 mg/KgDW. The amount of accumulated antimony in the roots was more than aerial parts. Also, with increasing antimony concentration in nutrient solution, the content of chlorophyll a and b were decreased. When antimony concentration in nutrient solution was up to 5 mg/L, the ratio of chlorophyll a/b was increased. The amount of carotenoids and catalase and ascorbat peroxidase activities also increased with increasing of antimony concentration in nutrient solution. In conclusion, Tanacetum polycephalum has a relatively high tolerance to antimony. It is able to uptake and accumulate antimony in its aerial parts; therefore this plant can be used to remediation of antimony contaminated soils.

Heavy metals are largely found in dispersed form in rock formations. Industrialization and urbanization have increased the anthropogenic contribution of heavy metals in the biosphere. Heavy metal pollution not only affects the production and the quality of crops, but also influences the quality of the atmosphere and water bodies, and threatens the health and life of human beings. Clean-up technologies have been developed for the removal of heavy metals but often these are expensive or have some environmentally deleterious consequences. Phytoremediation emerged in the early 1980s is an important technology for remediation of contaminated sites. One of the most promising phytoremediation technologies is phytoextraction using hyperaccumulators to remove heavy metals from contaminated soils. However, the known hyperaccumulator plants usually accumulate only a specific element and are usually small. Recently, most attention is focused to the plants that produce high biomass and are tolerant to the soils pollutted with heavy metals. T. caerulescens was found to colonize areas with high Cd, Cu, Pb, and Zn present in soils due to mining. M. chenopodiifolia has good potential for absorbing Pb and Zn. Eruca sativa is tolerante to soil pollution with heavy metals and can accumulate Pb and Cd from contaminated soils. B. napus accumulated cadmium and zinc and translocated these elements into the harvestable parts of the plant. S. nigrum is often found in contaminated areas. It has previously been identified as a Cd hyperaccumulator. H. annuus is known for its high biomass yield. In addition, it is tolerant to soil pollution with heavy metals. Z. mays produce high biomass as well. In this study, we studied the capability of stability, growth, and uptake of heavy metals by means of T. caerulescen, Z. mays, H. annuus, E. sativa, B. napus, S. nigrum, and M. chenopodiifolia on the industrial discharge of Mobarakeh Steel Complex.

The aim of present study was evaluation of IAA and kinetin effects on lead uptake and accumulation in Matthiola flavida. Metallicolous population of M. flavida was grown in hydroponic condition. Then plants were exposed to combination of 1µM Pb and 0, 1, 10, 100 µM IAA and kinetin for 14 days. Finally, Pb concentration was determined in their aerial parts and roots using a flam atomic absorption. Also their Chlorophyll contents were measured and calculated by spectrophotometer. Results showed increasing aerial part Pb concentration more than 48 and 110% respectively in 1 and 10 µM IAA comparing to control. A significant decreasing aerial part Pb concentration was observed with increasing of kinetin concentration in culture medium. Root Pb concentration significantly decreased with increasing of auxin and kinetin in nutrient solution. Significant differences in aerial part dry weight were not observed in different IAA and kinetin concentrations in comprising with control. Increasing aerial part Pb concentration in M. flavida was observed in low concentration of IAA but kinetin did not show clear and positive effects on biomass and Pb concentration.

Arsenic is chemically similar to phosphorus which study of their interaction is important for understanding their uptake and accumulation in plants. In this study effect of different arsenate and phosphate treatment on biomass and their accumulation in two wheat cultivars (Zarin and Sardari) were investigated. The plants were grown in Hoagland’s solution for 3 weeks then treated with different concentrations of arsenate (0-250 µM) and phosphate (0-300 µM). The results showed that phosphorus has significant effect on arsenic uptake and accumulation and root and shoot biomass. The low treatments of phosphorus (0-50 µM) had less effect on accumulation of arsenic and biomass in two cultivars but plant biomass and arsenic accumulation increased significantly with increasing phosphorus concentrations (150-300 µM). Also the low concentrations of arsenate had no significant effect on phosphorus uptake and plant biomass, which these criteria decreased significantly at high arsenic treatments. In conclusion, this study shows that applying appropriate treatments of phosphorus in arsenic contaminated solutions can be used as important technique for decreasing arsenic in harvestable parts of wheat cultivars.

Cadmium is a non-essential divalent heavy metal cation. The toxic level of Cd may be caused by natural soil charscteristics or by human activity. Cd has been shown to cause many morphological, physiological, biochemical and structural changes in growing plants. Meanwhile, some plant species can grow in Cd-contaminated soil and are able to uptake and accumulate this element in their tissues. Matthiola chenopodiifolia, is a plant that is able to grow in heavy metals contaminated soils in Irankouh mining area. In this study, in order to determine the potentiality of this plant to accumulate of Cd, it was grown under different concentration of Cd in laboratory conditions. The seeds of M. chenopodiifolia were collected from plants grown on contaminated soils (Irankouh) and uncontaminated soils (Soffeh) around Isfahan. Plants were grown in hydroponic system with modified Hoagland nutrient solution for 10 days. Then, the plants were treated with Cd concentrations of 0, 2.5, 5, 10, 20, 30 and 40 ppm for 24 days. Results showed that the root and shoot dry weight in both populations were decreased with increasing concentration of cadmium. Also root tolerance index in both populations significantly decreased (P<0.05). In addition, both populations of M. chenopodiifolia were able to accumulate cadmium in their roots and shoots under all concentration of Cd. Uptake and accumulation of Cd were increased by increasing Cd concentration. Also, both populations had no significant differences in response to Cd, therefore, M. chenopodiifolia had an innate tolerance to Cd and was a very useful plant for phytoremediating of Cd from contaminated soils.