Effects of silicon on manganese and lead contents in cell wall polysaccharide components of rice seedling leaves under manganese-lead combined stress
[Objective]The study aimed to explore the effects of different concentrations of SiO2 on manganese(Mn)and lead(Pb)contents in cell wall polysaccharide components of rice seedling leaves under Mn-Pb composite stress,and to provide theoretical basis for the use of ag-ronomic measures to treat heavy metal composite pollution in mining fields.[Method]Under the premise of simulating heavy metal pollution in the mining area,rice seeds were first cultivated to 5 leaves and 1 heart stage by hydroponics,and then rice seedlings were subjected to com-pound stress with 2 mmol/L Mn2++2 mmol/L Pb2+solution.Six SiO2 treatment concentrations were set:0(control group,CK),70,90,110,130,and 150 mg/L.After treatment,cell wall polysaccharide components of rice seedling leaves were extracted,and the contents of Mn and Pb were determined and analyzed.[Result]The content of Mn and Pb in the polysaccharide components of cell wall(pectin,hemicellu-lose and cellulose)was increased by SiO2 application.Compared with CK,the contents of Mn and Pb in cell wall pectin were higher when the concentration of SiO2was 70-110 mg/L.Under the treatment of SiO2,the content of Pb was greater than Mn content in pectin,and when the concentration of SiO2was less than 90 mg/L,the content of Pb was less than Mn in the leaf cell wall of rice seedlings.When the concentration of SiO2 was 110 mg/L,the content of Mn and Pb was relatively high in hemicellulose and cellulose.The content of Pb in the cell wall hemi-cellulose of rice seedling leaves was higher than the Mn content,and content of Pb in cellulose was negative when the concentration of SiO2 was less than 90 mg/L.When SiO2 was not applied(CK),the main binding sites of Mn and Pb were cellulose and pectin respectively,and the main binding sites of Pb were transferred to hemicellulose when SiO2 was applied.[Conclusion]SiO2 can increase the content of heavy metals Mn and Pb in the cell wall polysaccharide components.Under Mn-Pb combined stress,when SiO2 concentration is 110 mg/L,Mn and Pb contents are more in cell wall,pectin,hemicellulose and cellulose.
NETL
NSTL
万方数据
