Nitrate reductase activity and its diurnal variation rhythm forCamptotheca acuminata seedlings

Abstract

Nitrate reductase activity (NRA) in different plant organs and leaves in different positions ofCamptotheca acuminata seedlings was determined by anIn vivo assay, the diurnal variation rhythm of NRA in leaves of different positions was observed, and the correlations between leaf NRA, leaf area and lamina mass per unit area (LMA) were also examined. The results showed that NRA in the leaf was significantly highest, compared with that in other organs such as roots, stems and leaves. In this experiment, the 10 leaves were selected from the apex to the base of the seedlings in order. The different NRA occurred obviously in leaves of different positions ofC. acuminata seedlings from the apex to the base, and NRA was higher in the 4th–6th leaves. The diurnal change rhythm of leaf NRA showed a one peak curve, and maximum NRA value appeared at about midday (at 12∶30 or so). No obvious correlations between NRA and leaf area or lamina mass per unit area were observed. This study offered scientific foundation for the further research on nitrogen metabolism ofC. acuminata.

Keywords

Camptotheca acuminata / Nitrate reductase activity / Diurnal variation

References

[1] Aslam M., Travis R.L., Rains D.W.. Diurnal fluctuations of nitrate uptake and in vivo nitrate reductase activity in Pima and Acala Cotton [J]. Crop Science, 2001, 41: 372-378.

[2] Black B.L., Fuchigami L.H., Coleman G.D.. Partitioning of nitrate assimilation among leaves, stems and roots of poplar [J]. Tree Physiology, 2002, 22: 717-724.

[3] Castle M. L., Rowarth J.S.. In vivo nitrate reductase activity in ryegrass (Lolium perenne) and white clover (Trifolium repens): differences due to nitrogen supply, development and plant part[J]. New Zealand Journal of Agricultural Research, 2003, 46: 31-46.

[4] Geiger M., Walch-Liu P., Engels C., et al. Enhanced carbon dioxide leads to a modified diurnal rhythm of nitrate reductase activity in older plants, and a large stimulation of nitrate reductase activity and higher levels of amino acids in young tobacco plants [J]. Plant Cell and Environment, 1998, 21: 253-268.

[5] Högberg P., Högbom L., Schinkel H.. Nitrogen-related root variables of trees along an N-deposition gradient in Europe [J]. Tree Physiology, 1998, 18: 23-828.

[6] Huber J.L., Redinbaugh M.G., Huber S.C., et al. Regulation of maize leaf nitrate reductase activity involves both gene expression and protein phosphorylation [J]. Plant Physiology, 1994, 106: 1667-1674.

[7] Hunter J.J., Ruffner H.P.. Diurnal and seasonal changes in nitrate reductase activity and nitrogen content of grapevines: effect of canopy management [J]. Vitis, 1997, 36(1): 1-6.

[8] Jin S.N., Lee H.J., Oh S.D.. Growth, leaf nitrogen contents, and nitrate reductase activity in pear (Pyrus pyrifolia cv. Niitaka) trees as affected by ammonium and nitrate nitrogen supply [J]. Journal of Korean Society Horticulture Science, 2003, 44(1): 82-86.

[9] Lambers H., Chapin F.S., Pons T.L.. Plant physiological ecology [M]. 1998, New York: Spring-Verlag New York Inc, 252 253

[10] Scheible W.R., Gonzalez-Fontes A., Lauerer M., et al. Nitrate acts as a signal to induce organic acid metabolism and repress starch metabolism in tobacco [J]. Plant Cell, 1997, 9(5): 783-798.

[11] Söthr C., Mäck G.. Diurnal changes in nitrogen assimilation of tobacco roots [J]. Journal of Experimental Botany, 2001, 52: 1283-1289.

[12] Sun Shiqin, Yan Xiufeng. Determination method of nitrate reductase activity in the leaves ofCamptotheca acuminata [J]. Journal of Northeast Forestry University, 2004, 32(3): 83-84. (in Chinese)

[13] Vogel C.S., Dawson J.O.. Nitrate reductase activity, nitrogenase activity and photosynthesis of black alder exposed to chilling temperatures [J]. Physiological Plant, 1991, 82: 551-558.

[14] Yuefu Wang, Zhenwen Yu, Li Shangxia, et al. Comparison of nitrate reductase and glutamine synthetase activities in different organs of wheat after flowering [J]. Plant Physiology Communications [J], 2003, 39(3): 209-210. (in Chinese)

[15] Shangbin Wen, Lianxuan Shi, Dansheng Wang, et al. Studies on the relationship among leaf photosynthetic rate, respiration rate, nitrate reductase activity and soluble protein of Soybean [J]. Journal of Northeast Normal University, 1999, 1: 67-70. (in Chinese)

[16] Guozhang Zhou, Mengyun Su. Preliminary study on nitrate reductase of Chinese fir [J]. Scientia Silvae Sinicae, 1998, 24(2): 156-161. (in Chinese)