The Role Of Amino Acids In The Long-Distance Transport Of La And Y In The Xylem Of P.Americanal And Tomato

Since 1970s, because of their widely industrial and agricultural usage, more and more Rare Earth Elements(REEs) are getting into the environment. REE pollution is Chinese characteristic environment problem. REEs have already been classified as main environmental pollutants in China since 1990s. Therefore, remediation of REE contaminated is drawing more and more attentions.Phytoextraction uses plants for removing contaminants from soils, which was first introduced in 1983, and subsequently gained public exposure in the 1990s because of its low cost, high efficiency and environmental friendly. Because the remediation of REE contaminated is less studied, Phytoextraction have not been widely applied to REE contaminated in China. It is key problem of Phytoextraction how to increase absorption and translocation of lanthanum and yttrium in the tomato. Based on the situation above, the objectives of this research were the roles of amino acid in xylem saps translocation of lanthanum and yttrium in the tomato. By studying the role of amino acids in xylem saps may help us in applying Phytoextraction to remediation of REE contaminated.Main results were as follows:1) The objectives of these parts were the roles of amino acid in xylem saps translocation of La and Y in the tomato. The concentration of glutamic acid in xylem sap significantly increased in the La and Y treatment compared to the control. By analyzing the correlation between concentrations of amino acids and concentrations of La and Y in the xylem saps, we considered that the glutamic acid in xylem saps seemed to participate in the long-distance La and Y translocation process.2) This experiment was carried out to compare the influences of amino acids application on La and Y translocation in the xylem sap of tomato. The results implied that glutamic acid might be as ligand with La (or Y) to reinforce La (or Y) absorption, transportation and immobilization in tomato. The histidine might be also as ligand with La to reinforce La absorption, transportation and immobilization in tomato. However, The aspartic acid and asparagine might be as ligand with Y to reinforce Y absorption, transportation and immobilization in tomato. 3) The objectives of these parts were the roles of amino acid in xylem saps translocation of La and Y in the P.americanaL. By analyzing the correlation between concentrations of amino acids and concentrations of La and Y in the xylem saps, we considered that the aspartic acid, histidine, asparagine and glutamic acid in xylem saps seemed to participate in the long-distance La translocation process, while the histidine, asparagine and glutamic acid seemed to make a role of the Y transloation in the xylem vessels of P.americanaL.