Effects Of Soil Cadmium Pollution On Phytochelatins In Wheat

Since the middle of the last century, in the word, agriculture and industry rapid development, factory pollution, excessive mining, sewage irrigation, and a series of behavior caused a large number of pollutants into the environment, and the soil because of its porous structure characteristics, for a long time to absorb and accumulate a large amount of pollutants in soil quality worsen sharply. All kinds of pollution in the soil, heavy metals due to its many source sex, cumulative, concealment and other features, has become a human faces and a serious environmental problem to be solved. Long time of soil heavy metal pollution,pollution and difficult to be degradation or completely separated from the soil, and as the absorption of plant roots on soil heavy metals, heavy metals into the food chain transfer and enrichment of the ecological system, eventually harm to people’s health. So the soil heavy metal pollution is no longer a pure environment pollution problem, it’s about the human body health and for the future development of a big deal. This study of 18 kinds of typical soil background, the research of low concentration and long time under the soil polluted by heavy metal cadmium multiple physiological period of wheat in wheat leaves TNP, GSH, PCs synthesis. Explores the longer within the scope of soil cadmium pollution in wheat leaves under PCs synthetic quantity change rule. Research of in acidic soil under the condition of different soil physical and chemical properties and heavy metal cadmium pollution leaf in different growth period of wheat plants under complex element PCs to explore the relationship between synthesis an PCs. The following main conclusions:1. For a long time and low concentration of soil heavy metal cadmium pollution under wheat leaf china-africa protein thiol compounds synthesis(1) The experiment set range, with the concentration of heavy metal cadmium Cd in soil increases, the wheat tillering stage blades of TNP levels increased significantly(P < 0.05).Even if the heavy metal cadmium Cd had no observable on wheat plant biomass in poison,wheat leaves of TNP on soil heavy metal Cd content in the reaction still sensitive, showed a positive correlation between.(2) As the concentration of heavy metal Cd in soil increases, the wheat tillering stage blades of GSH content significantly reduced(P < 0.05). Wheat leaf in the synthesis of GSH while the heavy metal Cd content in soil changes have certain reactions, modest, but change is not obvious, so it is difficult to through the wheat leaf in GSH content in the soil heavy metalpollution situation of Cd.(3) As the concentration of heavy metal Cd in soil increases, the wheat tillering stage plants of complexing element PCs content in the leaves increased significantly(P < 0.05), and increase the rules in different zonal soil stability, with change rule of Cd concentration is better than that of TNP and GSH. This suggests that even if the heavy metal Cd not quantifiable poison on wheat plant biomass, plant complexation of wheat leaf PCs on the soil heavy metal Cd content in the reaction is more sensitive to the concentration showed a good dose- effect relationship between, proved by testing in the cellular level of PCs in wheat to evaluate or predict farmland soil heavy metal pollution situation of Cd.(4) At wheat tillering period of leaf plant PCs/TNP with the heavy metal Cd into having increased significantly(P < 0.05), about 80%, similar to the related research results at home and abroad, the change law were evident in all the tested soil. It also shows that in the face of the soil heavy metal Cd content increases, the PCs synthesis of a large increase in volume,further proves the plant PCs content and concentration of Cd in soil dose- effect relationship,a further indication of PCs is an efficient and sensitive biological indicator of soil polluted by heavy metal Cd.2. Regular of PCs in different physiological periods of wheat under Cd pollution.(1) At low concentration, long time of soil cadmium exposure, wheat leaf in PCs synthesis in tillering stage formed a huge amount of peak, wheat PCs in the leaves of change regulation of the synthesis of "∧" type.(2) PCs in wheat tillering formation of the peak and the period of wheat growth rate of wheat growth cycle in time and change rule of peak height, which further proves the PCs as a kind of sensitive physiological indexes in the biological indicator of soil heavy metal cadmium pollution.3. The relationship of soil physical and chemical properties and wheat PCs under the condition in acidic soil.(1) Within the scope of the experimental set, acidic soils, AV.P effective state and wheat PCs showed a significant negative correlation relationship between synthetic quantity, with the increase of effective state of P in soil, wheat plant complex synthetic quantity significantly reduced. Prediction in acid soil can increase phosphorus in part in slow the biological toxicity of heavy metal cadmium on wheat.(2) In the experimental setting, within the scope of the acidic soil, the soil CEC and wheat PCs show significant negative correlation relationship between synthetic quantity, show that with the increase of soil cation exchange capacity, wheat plant complex synthetic quantity significantly reduced. Speculation in acidic soil can improve soil cation exchange capacity in a certain extent reduce the heavy metal cadmium in biological toxicity of wheat.(3)In the experimental setting, within the scope of the acidic soil, the soil of Free iron oxide and wheat PCs show significant positive correlation between synthetic quantity, show that with the increase of Free iron oxide content in the soil, the synthetic quantity of wheat plant complexing increased significantly. Guess PCs may be involved in maintaining wheat free iron ion in the process of the dynamic balance in the body.(4) Under the changeable and complex medium of soil physical and chemical properties,proves that the PCs is sensitive to soil heavy metal cadmium concentrations of reflection,further illustrates the PCs in the early to predict the tendency of the soil heavy metal cadmium pollution.