Accumulation Characteristics Of Pb,Cu With Single Or Combined Pollution And Their Influence On The Contents Of Protein And Organic Acid

The elements Cu and Pb are two important heavy metal pollutants which have great toxicity effect on the growth,development and metabolism of crops.Zea mays is selected In this paper as the material in the experiment. Indoor earth-foster method is applied to study the effects of accumulation and distribution,oxalic acid and total soluble protein contents,ATPase and peptidase activities in Z mays under single or combined pollution of Cu2+ and Pb2+ with different concentrations(10 mg·L-1,50mg·L-1,100mg·L-1). The results are as follows:The dynamic changing rule of Cu2+,Pb2+ with different concentrations on accumulating and distributing in Z mays seedling. The results shows that under single or combined pollution of Cu2+ and Pb2+, the content of heavy metals in Z.mays seedlings enhances with the increasing of treatment concentration and treatment duration, and the accumulation amount in roots of Z.mays seedlings is the largest at 30d with 100 mg·L-1 of heavy metals.The content of Cu2+ or Pb2+ in different organs of Z. mays seedlings is characterized by roots> stems>leaves, and the accumulation amount in each organ is Pb2+>Cu2+.The accumulation amount of Cu2+, Pb2+ in Z. mays Seedlings under combined pollution was much more than that under single pollution, and it indicated that compared with the single pollution, the combined pollution by Cu2+ and Pb2+ displays some kind of synergistic effect. Meanwhile, the mobility of Cu2+,Pb2+ is basically dependent on Cu2+, Pb2+ concentration and treatment duration. The mobility between roots and stems under Cu2+ or Pb2+single pollution increased with heavy metal concentration, but the mobility between stems and leaves firstly declined, and then increased with increasing of Cu2+ or Pb2+ concentration.The mobility between stems and leaves under combined pollution was larger than that under single pollution.Effects on the contents of oxalic acid under single or combined pollution of Cu2+ and Pb2+ with different concentrations in Z. mays seedling are studied.The result indicated that the contents of oxalic acid enhances with the increasing of treatment concentration and treatment under single pollution of Cu2+,Pb2,and the oxalic acid amount in Z. mays seedlings is the largest at the duration of 30d.the oxalic acid amount under single Pb2+pollution is larger than that under single Cu2+ pollution.compared with Cu2+,Pb2 single pollution, the combined pollution by Cu2+ and Pb2+displays some kind of stimulation effect.Effects of Cu2+,Pb2+ on soluble protein with different concentrations in Z. mays seedling are researched. The result explained that the soluble protein in Z. mays seedling under Cu2+ single pollution firstly declined, and then increased with increasing of copper concentration.The amount of soluble protein under Pb2+ single pollution increases with the enhancing of treatment concentration except the condition of Pb2+ single pollution at 10d in root of Z. mays.soluble protein amount extremly reduces under combined pollution by Cu2+ and Pb2+.The influence upon the activities of ATPase and peptidase with Cu2+, Pb2+ stress in Z. mays seedling are studied.the result showed that the activities of ATPase firstly increased, and then declined with increasing of copper concentration with Cu2+ single pollution. Under Pb2+ single pollution,the activities of ATPase declined with enhancing of lead concentration.On the condition of Cu2+ and Pb2+ combined pollution, the activities of ATPase also reduced,and the tendency of reduction was faster than that under Cu2+,Pb2+ single pollution.The change rules of the activities of peptidase are different between roots and leaves in Z.mays under Cu2+ single pollution,which declined in roots and firstly increased, and then reduced in leaves.With Cu2+ and Pb2+ combined pollution, the activities of peptidase declined,especialy in leaves, the tendency of reduction of peptidase is extremely faster than that of Cu2+,Pb2+ single pollution.compared with the single pollution, the combined pollution by Cu2+ and Pb2+ displays some stronger Inhibitory action.