Arabidopsis thaliana seedlings were cultivated in 0-500 μmol/L of extraneous cerium （Ce） for 7 d to investigate the toxicity, uptake and translocation of rare earth elements （REEs）. The results showed that Ce cou...Arabidopsis thaliana seedlings were cultivated in 0-500 μmol/L of extraneous cerium （Ce） for 7 d to investigate the toxicity, uptake and translocation of rare earth elements （REEs）. The results showed that Ce could be largely absorbed by the roots ofA. thaliana and translocated to the shoots. But the uptake rates of Ce by the roots were much higher than the translocation rates from roots to shoots. Ultrastructural analysis revealed that Ce was mainly distributed on the cell wall. At higher concentration, Ce could also enter cell, destroy the ultrastructure of cells and disturb the intrinsic balance of nutrient elements of A, thaliana, Addition of Ce （50-500 μmol/L） to the culture medium significantly inhibited the elongation of primary roots, decreased chlorophyll content, rosette diameter and fresh mass of plants. The damage increased with the increase of Ce concentration in culture medium, although primary root elongation, chlorophyll content, and rosette diameter were stimulated by relatively low concentration （0.5 μmol/L） of Ce. Thus, it is speculated that REEs may become a new type contamination if we don＇t well control the release of REEs into the environment.展开更多
[Objective] This study aimed to investigate the physiological and biochemi- cal effects of lanthanum （La3＋）, cerium （Ce3＋）, zinc （Zn2＋） on rice roots and explore the environmental effects of excessive applica...[Objective] This study aimed to investigate the physiological and biochemi- cal effects of lanthanum （La3＋）, cerium （Ce3＋）, zinc （Zn2＋） on rice roots and explore the environmental effects of excessive application of rare earth. [Method] By using rare earth elements La3＋ and Ce3＋, and nutritional and toxic heavy metal element Zn2＋ as stress factors, the effects of these three elements on the germination of rice seeds, growth and development of seedlings were studied and compared by using tissue culture method. [Result] La3＋, Ce3＋ and Zn2＋ had no significant effect on germi- nation rate of rice seeds but significant inhibition effects on the growth of roots and shoots of rice seedlings, and the inhibition effects of rare earth elements in high concentrations were stronger than Zn2＋; the content of soluble protein in rice roots showed a rising-decreasing trend with the increasing concentrations of three metal ions, La3＋ and Ce3＋ were more sensitive than Zn2＋; the activities of CAT and POD increased with the increasing concentrations of La3. and Ce3＋, while the SOD activity had shown the tendency of decreased first and increased later; the three metal ions all could significantly stimulate the rapid accumulation of MDA in rice roots. La3＋ and Ce3＋ had stronger toxic effects at high concentrations than Zn2＋, [Conclusion] Toxic mechanism of rare earth elements La＋ and Ce3. is similar to that of heavy metal el- ement Zn2＋. Rare earth might become a new type of pollution in the long run.展开更多
基金National Natural Science Foundation of China(30900071,30671126)
文摘Arabidopsis thaliana seedlings were cultivated in 0-500 μmol/L of extraneous cerium （Ce） for 7 d to investigate the toxicity, uptake and translocation of rare earth elements （REEs）. The results showed that Ce could be largely absorbed by the roots ofA. thaliana and translocated to the shoots. But the uptake rates of Ce by the roots were much higher than the translocation rates from roots to shoots. Ultrastructural analysis revealed that Ce was mainly distributed on the cell wall. At higher concentration, Ce could also enter cell, destroy the ultrastructure of cells and disturb the intrinsic balance of nutrient elements of A, thaliana, Addition of Ce （50-500 μmol/L） to the culture medium significantly inhibited the elongation of primary roots, decreased chlorophyll content, rosette diameter and fresh mass of plants. The damage increased with the increase of Ce concentration in culture medium, although primary root elongation, chlorophyll content, and rosette diameter were stimulated by relatively low concentration （0.5 μmol/L） of Ce. Thus, it is speculated that REEs may become a new type contamination if we don＇t well control the release of REEs into the environment.
基金Supported by National Natural Science Foundation of China (30900071)PhD Research Start-up Fund of Shandong University of Technology (4041-406027)~~
文摘[Objective] This study aimed to investigate the physiological and biochemi- cal effects of lanthanum （La3＋）, cerium （Ce3＋）, zinc （Zn2＋） on rice roots and explore the environmental effects of excessive application of rare earth. [Method] By using rare earth elements La3＋ and Ce3＋, and nutritional and toxic heavy metal element Zn2＋ as stress factors, the effects of these three elements on the germination of rice seeds, growth and development of seedlings were studied and compared by using tissue culture method. [Result] La3＋, Ce3＋ and Zn2＋ had no significant effect on germi- nation rate of rice seeds but significant inhibition effects on the growth of roots and shoots of rice seedlings, and the inhibition effects of rare earth elements in high concentrations were stronger than Zn2＋; the content of soluble protein in rice roots showed a rising-decreasing trend with the increasing concentrations of three metal ions, La3＋ and Ce3＋ were more sensitive than Zn2＋; the activities of CAT and POD increased with the increasing concentrations of La3. and Ce3＋, while the SOD activity had shown the tendency of decreased first and increased later; the three metal ions all could significantly stimulate the rapid accumulation of MDA in rice roots. La3＋ and Ce3＋ had stronger toxic effects at high concentrations than Zn2＋, [Conclusion] Toxic mechanism of rare earth elements La＋ and Ce3. is similar to that of heavy metal el- ement Zn2＋. Rare earth might become a new type of pollution in the long run.
