Pedosphere 18(5): 664--673, 2008
ISSN 1002-0160/CN 32-1315/P
©2008 Soil Science Society of China
Published by Elsevier B.V. and Science Press
Effect of nitrate on activities and transcript levels of nitrate reductase and glutamine synthetase in rice |
CAO Yun, FAN Xiao-Rong, SUN Shu-Bin, XU Guo-Hua, HU Jiang and SHEN Qi-Rong |
College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China). E-mail: youngtsao66@yahoo.com.cn |
ABSTRACT |
Real-time polymerase chain reaction analysis was used to compare the effect of NO3- on the activities of nitrate reductase (NR)and glutamine synthetase (GS), and the transcript levels of two NR genes, OsNia1 and OsNia2, two cytosolic GS1 genes, OsGln1;1 and OsGln1;2, and one plastid GS2 gene OsGln2, in two rice (Oryza sativa L.)cultivars Nanguang (NG)and Yunjing (YJ).Both cultivars achieved greater biomass and higher total N concentration when grown in a mixed N supply than in sole NH4+ nutrition.Supply of NO3- increased NR activity in both leaves and roots.Expression of both NR genes was also substantially enhanced and transcript levels of OsNia2 were significantly higher than those of OsNia1.NO3- also caused an increase in GS activity, but had a complex effect on the expression of the three GS genes.In roots, the OsGln1;1 transcript increased, but OsGln1;2 decreased.In leaves OsGln1;2 had no effect on the GS1 expression, but the transcript for OsGln2 increased both in the leaves and roots of rice with a mixed supply of N.These results suggested that the increase in GS activity might be a result of the complicated regulation of the various GS genes. In addition, the NO3- induced increase of biomass, NR activity, GS activity, and the transcript levels of NR and GS genes were proportionally higher in NG than in YJ, indicating a stronger response of NG to NO3- nutrition than YJ. |
Key Words: ammonium, glutamine synthetase, nitrate, nitrate reductase, Oryza sativa L. |
Citation: Cao, Y., Fan, X. R., Sun, S. B., Xu, G. H., Hu, J. and Shen, Q. R. 2008. Effect of nitrate on activities and transcript levels of nitrate reductase and glutamine synthetase in rice. Pedosphere. 18(5): 664-673. |
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