The effects of nitrogen on physiological and biochemical characteristics of potato cultivar Zihuabai under NaCl stress were studied in culture condition.The results show that,under NaCl stress,the contents of proline,...The effects of nitrogen on physiological and biochemical characteristics of potato cultivar Zihuabai under NaCl stress were studied in culture condition.The results show that,under NaCl stress,the contents of proline,chlorophyll and protein and root system vitality first increase and then decrease with the increase of nitrogen level,and reach the top under 4.17 mmol/L NH4NO3 level.Wherein,the contents of chlorophyll,protein and root system vitality are respectively 69.88%,13.07% and 59.29% higher than that of the control under 4.17 mmol/L NH4NO3 level;the activities of superoxide dismutase（SOD）and peroxidase（POD）increase generally under NaCl stress with the increase of nitrogen level,and reach the peaks [111.83 U/g and 25.467 U/（g·min）],which are 37.73% and 35.46% higher than that of control,at 6.25 mmol/L NH4NO3 level.展开更多
Abstract Many species of microalga Dunaliella exhibit a remarkable tolerance to salinity and are therefore ideal for probing the effects of salinity. In this work, we assessed the effects of NaC1 stress on the growth,...Abstract Many species of microalga Dunaliella exhibit a remarkable tolerance to salinity and are therefore ideal for probing the effects of salinity. In this work, we assessed the effects of NaC1 stress on the growth, activity and mRNA level of carbon and nitrogen metabolism enzymes of D. viridis. The alga could grow over a salinity range of 0.44 mol L-t to 3.00 mol L-1 NaCI, but the most rapid growth was observed at 1.00molL-1NaC1, followed by 2.00 molL-l NaC1. Paralleling these growth patterns, the highest initial and total Rubisco activities were detected in the presence of 1.00molL-t NaC1, decreasing to 37.33% and 26.39% of those values, re- spectively, in the presence of 3.00 mol L-1 NaC1, respectively. However, the highest extracellular carbonic anhydrase （CA） activity was measured in the presence of 2.00molL-1 NaC1, followed by 1.00molL-1NaC1. Different from the two carbon enzymes, nitrate reductase （NR） activity showed a slight change under different NaC1 concentrations. At the transcriptional level, the mRNAs of Rubisco large subunit （rbcL）, and small subunit （rbcS）, attained their highest abundances in the presence of 1.00 and 2.00molL-1 NaC1, respectively. The CA mRNA accumulation was induced from 0.44molL ~ to 3.00molL-1 NaC1, but the NR mRNA showed the decreasing tendency with the increasing salinity. In conclusion, the growth and carbon fixation enzyme of Rubisco displayed similar tendency in response to NaC1 stress, CA was proved be salt-inducible within a certain salinity range and NR showed the least effect by NaC1 in D. viridis.展开更多
基金Supported by National Key Technology Research and Development Program(2007BAD49B03-1)~~
文摘The effects of nitrogen on physiological and biochemical characteristics of potato cultivar Zihuabai under NaCl stress were studied in culture condition.The results show that,under NaCl stress,the contents of proline,chlorophyll and protein and root system vitality first increase and then decrease with the increase of nitrogen level,and reach the top under 4.17 mmol/L NH4NO3 level.Wherein,the contents of chlorophyll,protein and root system vitality are respectively 69.88%,13.07% and 59.29% higher than that of the control under 4.17 mmol/L NH4NO3 level;the activities of superoxide dismutase（SOD）and peroxidase（POD）increase generally under NaCl stress with the increase of nitrogen level,and reach the peaks [111.83 U/g and 25.467 U/（g·min）],which are 37.73% and 35.46% higher than that of control,at 6.25 mmol/L NH4NO3 level.
基金funded by the Project of Science and Technology Innovation Team of Zhejiang Province (2010R50025-25)sponsored by the K. C. Wong Magna Fund
文摘Abstract Many species of microalga Dunaliella exhibit a remarkable tolerance to salinity and are therefore ideal for probing the effects of salinity. In this work, we assessed the effects of NaC1 stress on the growth, activity and mRNA level of carbon and nitrogen metabolism enzymes of D. viridis. The alga could grow over a salinity range of 0.44 mol L-t to 3.00 mol L-1 NaCI, but the most rapid growth was observed at 1.00molL-1NaC1, followed by 2.00 molL-l NaC1. Paralleling these growth patterns, the highest initial and total Rubisco activities were detected in the presence of 1.00molL-t NaC1, decreasing to 37.33% and 26.39% of those values, re- spectively, in the presence of 3.00 mol L-1 NaC1, respectively. However, the highest extracellular carbonic anhydrase （CA） activity was measured in the presence of 2.00molL-1 NaC1, followed by 1.00molL-1NaC1. Different from the two carbon enzymes, nitrate reductase （NR） activity showed a slight change under different NaC1 concentrations. At the transcriptional level, the mRNAs of Rubisco large subunit （rbcL）, and small subunit （rbcS）, attained their highest abundances in the presence of 1.00 and 2.00molL-1 NaC1, respectively. The CA mRNA accumulation was induced from 0.44molL ~ to 3.00molL-1 NaC1, but the NR mRNA showed the decreasing tendency with the increasing salinity. In conclusion, the growth and carbon fixation enzyme of Rubisco displayed similar tendency in response to NaC1 stress, CA was proved be salt-inducible within a certain salinity range and NR showed the least effect by NaC1 in D. viridis.
