[Objective]This study aimed at exploring the physiological properties of the known Cd hyperaccumulator Viola baoshanensis and the control plant Viola inconspicua to cadmium stress.[Method]After a hydroponic experiment...[Objective]This study aimed at exploring the physiological properties of the known Cd hyperaccumulator Viola baoshanensis and the control plant Viola inconspicua to cadmium stress.[Method]After a hydroponic experiment carried in a greenhouse,plant Cd accumulations,root elongation rates,MDA contents,and antioxidant enzyme activities were determinined.[Result]Both Viola baoshanensis and Viola inconspicua showed high levels of Cd uptake growing in Cd-supplemented solution of 300 μmol/L for 12 d with Cd accumulations of 2 595 and 3 330 mg/kg in the shoots,respectively.In the cultural solution supplemented with 300 μmol/L of Cd,the root elongation rates were not affected and the MDA contents decreased significantly in Viola baoshanensis,while the root elongation rates were significantly inhibited and the MDA contents increased remarkably in Viola inconspicua,which indicated that Viola baoshanensis had the higher Cd tolerance.The superoxide dismutase（SOD）,peroxidase（POD）and catalase（CAT）activities of two Viola species were not linearly related to the middle and low Cd-supplemented concentrations（5,50 μmol/L）and had attained the tiptop in cultural solution supplemented with 100 or 300 μmol/L of Cd but declined in cultural solution supplemented with 500 μmol/L of Cd,suggesting that the contribution of antioxidative enzymes was limited to the Cd tolerance of Viola plants.The Viola inconspicua showed a strong adaptability to the middle and low concentrations of Cd.[Conclusion]Viola species could be used as potential plant resources for the phytoremediation of agriculture areas polluted with low and even middle levels of Cd.展开更多
The research used bioassay method to explore seed tolerance of Cd in terms of seed germination and seedling growth. Specifically, 12 rice varieties of three types were investigated under Cd stress, covering germinatio...The research used bioassay method to explore seed tolerance of Cd in terms of seed germination and seedling growth. Specifically, 12 rice varieties of three types were investigated under Cd stress, covering germination rate, shooting index, vigor index, seedling and shoot lengths, and fresh weights. The results showed that as Cd concentration grew, seed germination and seedling growth kept increasingly inhibited; germination index, vigor index, root length, shoot length and fresh weights went down; inhibition effects on seed germination and seedling growth were conventional rice〉two-line hybrid rice〉three-line hybrid ,rice. Shanyou 9588, Tianyou 998, Chuanxiang 8, and Y Liangyou 1 performed ~rongly in Cd tolerance; C Liangyou 651, Nei 5 You 263, Xiangwanxian 16, Huanghuazhan, Xiangwanxian 13, and Zhunliangyou 527 performed poorly in Cd tolerance, and Cd tolerance of rest treatments were moderate.展开更多
Sap mixtures of the xylem, phloem, and vacuoles from low and high Cd accumulator varieties of Brassica parachinensis L. H. Bailey were analyzed under Cd stress to understand the biochemical mechanisms of Cd accumulati...Sap mixtures of the xylem, phloem, and vacuoles from low and high Cd accumulator varieties of Brassica parachinensis L. H. Bailey were analyzed under Cd stress to understand the biochemical mechanisms of Cd accumulation in plants. Low Cd accumulator ('Teqing-60') and high Cd accumulator ('Chixin-2') plants were grown in Cd-treated soil in pots in a greenhouse. Percentage of cell wall-bound Cd was estimated. pH level and the concentrations of amino acids, organic acids, anions, and cations in both stem and root saps were determined for the calculation of Cd speciations using the computer program GEOCHEM. The results showed that 'Teqing-60' had a significantly higher (P≤0.05) percentage of Cd bound to cell walls in roots and a significantly higher (P≤0.05) pH in the root sap. 'Teqing-60' also contained a higher concentration of total amino acids in both roots and stems compared with the high Cd accumulator variety 'Chixin-2'. However, between the two accumulators, for stems and for roots, there were no significant differences in non-amino organic acids. GEOCHEM calculations showed that Cd in the root sap of 'Teqing-60' mainly combined with amino acids, especially alanine. Compared with 'Chixin-2', in the root sap of 'Teqing-60', much lower levels of Cd as free ions or bound to simple ligands were found, indicating that less 'Teqing-60' is transferred to stems and leaves. Cadmium activity in the shoot sap of 'Teqing-60' was much lower than that in 'Chixin-2'; therefore, 'Teqing-60' exhibited higher Cd resistance. However, direct determination of the Cd complexes from xylem and phloem sap is needed to verify these results.展开更多
The effects of salinity （50 mmol/L NaCI） and Cd （1 μmol/L CdCl2） as sole and combined on growth and photosynthetic parameters were studied using two soybean genotypes, Huachun 18 and NGB. The concentrations of C...The effects of salinity （50 mmol/L NaCI） and Cd （1 μmol/L CdCl2） as sole and combined on growth and photosynthetic parameters were studied using two soybean genotypes, Huachun 18 and NGB. The concentrations of Cd^2＋, Zn^2＋, Ca^2＋, Mg^2＋, K^＋ and Na^＋were also determined in seeds and pods. Huachun 18 suffered a more serious decrease than NGB in net photosynthetic rate （P,） in the treatments of salinity stress alone and combined stress （NaCl＋Cd）, showing that it is relatively sensitive to salinity. The decrease in P, caused by salt stress in Huachun 18 was mainly due to the reduced total chlorophyll content and photosynthetic efficiency （the ratio of variable fluorescence to maximal fluorescence, Fv/Fm）, whereas the decease in NGB was mainly related to reduced stomatal conductance （Gs）, The combined stress of both Na and Cd did not induce further decrease in photosynthesis and fluorescence in the two genotypes relative to salt or Cd stress alone. Greater change in the pod concentrations of Zn^2＋, Ca^2＋, Mg^2＋, K^＋ and Na^＋was detected under salt stress for Huachun 18 than for NGB. The results suggested that the interactive effect of NaCl-Cd on growth and nutrient uptake differs between the two soybean genotypes.展开更多
基金Supported by National Natural Science Foundation of China(30400053,30900158)the Open Project of State Key Laboratory of Biocontrol of Sun Yat-sen University(SKLBC2010K04)~~
文摘[Objective]This study aimed at exploring the physiological properties of the known Cd hyperaccumulator Viola baoshanensis and the control plant Viola inconspicua to cadmium stress.[Method]After a hydroponic experiment carried in a greenhouse,plant Cd accumulations,root elongation rates,MDA contents,and antioxidant enzyme activities were determinined.[Result]Both Viola baoshanensis and Viola inconspicua showed high levels of Cd uptake growing in Cd-supplemented solution of 300 μmol/L for 12 d with Cd accumulations of 2 595 and 3 330 mg/kg in the shoots,respectively.In the cultural solution supplemented with 300 μmol/L of Cd,the root elongation rates were not affected and the MDA contents decreased significantly in Viola baoshanensis,while the root elongation rates were significantly inhibited and the MDA contents increased remarkably in Viola inconspicua,which indicated that Viola baoshanensis had the higher Cd tolerance.The superoxide dismutase（SOD）,peroxidase（POD）and catalase（CAT）activities of two Viola species were not linearly related to the middle and low Cd-supplemented concentrations（5,50 μmol/L）and had attained the tiptop in cultural solution supplemented with 100 or 300 μmol/L of Cd but declined in cultural solution supplemented with 500 μmol/L of Cd,suggesting that the contribution of antioxidative enzymes was limited to the Cd tolerance of Viola plants.The Viola inconspicua showed a strong adaptability to the middle and low concentrations of Cd.[Conclusion]Viola species could be used as potential plant resources for the phytoremediation of agriculture areas polluted with low and even middle levels of Cd.
基金Supported by Loudi City Science and Technology Project(2014-1)State Key Laboratory of Hybrid RiceKey Laboratory of Pesticide Harmless Application of Hunan Province~~
文摘The research used bioassay method to explore seed tolerance of Cd in terms of seed germination and seedling growth. Specifically, 12 rice varieties of three types were investigated under Cd stress, covering germination rate, shooting index, vigor index, seedling and shoot lengths, and fresh weights. The results showed that as Cd concentration grew, seed germination and seedling growth kept increasingly inhibited; germination index, vigor index, root length, shoot length and fresh weights went down; inhibition effects on seed germination and seedling growth were conventional rice〉two-line hybrid rice〉three-line hybrid ,rice. Shanyou 9588, Tianyou 998, Chuanxiang 8, and Y Liangyou 1 performed ~rongly in Cd tolerance; C Liangyou 651, Nei 5 You 263, Xiangwanxian 16, Huanghuazhan, Xiangwanxian 13, and Zhunliangyou 527 performed poorly in Cd tolerance, and Cd tolerance of rest treatments were moderate.
基金Project supported by the National Natural Science Foundation of China (No. 40571141)the Natural Science Foundation of Guangdong Province (No. 021007)the Key Teachers Foundation of the Ministry of Education of China (No. 2000-143-39)
文摘Sap mixtures of the xylem, phloem, and vacuoles from low and high Cd accumulator varieties of Brassica parachinensis L. H. Bailey were analyzed under Cd stress to understand the biochemical mechanisms of Cd accumulation in plants. Low Cd accumulator ('Teqing-60') and high Cd accumulator ('Chixin-2') plants were grown in Cd-treated soil in pots in a greenhouse. Percentage of cell wall-bound Cd was estimated. pH level and the concentrations of amino acids, organic acids, anions, and cations in both stem and root saps were determined for the calculation of Cd speciations using the computer program GEOCHEM. The results showed that 'Teqing-60' had a significantly higher (P≤0.05) percentage of Cd bound to cell walls in roots and a significantly higher (P≤0.05) pH in the root sap. 'Teqing-60' also contained a higher concentration of total amino acids in both roots and stems compared with the high Cd accumulator variety 'Chixin-2'. However, between the two accumulators, for stems and for roots, there were no significant differences in non-amino organic acids. GEOCHEM calculations showed that Cd in the root sap of 'Teqing-60' mainly combined with amino acids, especially alanine. Compared with 'Chixin-2', in the root sap of 'Teqing-60', much lower levels of Cd as free ions or bound to simple ligands were found, indicating that less 'Teqing-60' is transferred to stems and leaves. Cadmium activity in the shoot sap of 'Teqing-60' was much lower than that in 'Chixin-2'; therefore, 'Teqing-60' exhibited higher Cd resistance. However, direct determination of the Cd complexes from xylem and phloem sap is needed to verify these results.
基金Project (No. Z304104) supported by Natural Science Foundation of Zhejiang Province, China
文摘The effects of salinity （50 mmol/L NaCI） and Cd （1 μmol/L CdCl2） as sole and combined on growth and photosynthetic parameters were studied using two soybean genotypes, Huachun 18 and NGB. The concentrations of Cd^2＋, Zn^2＋, Ca^2＋, Mg^2＋, K^＋ and Na^＋were also determined in seeds and pods. Huachun 18 suffered a more serious decrease than NGB in net photosynthetic rate （P,） in the treatments of salinity stress alone and combined stress （NaCl＋Cd）, showing that it is relatively sensitive to salinity. The decrease in P, caused by salt stress in Huachun 18 was mainly due to the reduced total chlorophyll content and photosynthetic efficiency （the ratio of variable fluorescence to maximal fluorescence, Fv/Fm）, whereas the decease in NGB was mainly related to reduced stomatal conductance （Gs）, The combined stress of both Na and Cd did not induce further decrease in photosynthesis and fluorescence in the two genotypes relative to salt or Cd stress alone. Greater change in the pod concentrations of Zn^2＋, Ca^2＋, Mg^2＋, K^＋ and Na^＋was detected under salt stress for Huachun 18 than for NGB. The results suggested that the interactive effect of NaCl-Cd on growth and nutrient uptake differs between the two soybean genotypes.
