Pedosphere 15(3): 363--368, 2005
ISSN 1002-0160/CN 32-1315/P
©2005 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| A modified method for measuring root iron reductase activity under normal laboratory conditions |
ZHENG Shao-Jian 1,2, HE Yun-Feng1, TANG Cai-Xian3 and Y. MASAOKA4 |
1 College of Environment and Resources, Zhejiang University, Hangzhou 310029 (China). E-mail: sjzheng@zju.edu.cn;
2 Kyushu Okinawa National Agricultural Research Center, Kumamoto 861-1192 (Japan);
3 Department of Agricultural Sciences, La Trobe University, Bundoora, Vic. 3086 (Australia);
4 Faculty of Applied Biological Science, Hiroshima University, Higashi Hiroshima 739-8528 (Japan) |
| ABSTRACT |
| Based on the strong chelating property of bathophenanthroline disulfonic acid (BPDS) with Fe(Ⅱ), root Fe(Ⅲ) chelate reductase activity is usually measured with a spectrophotometer using MES (2-morpholinoethanesulfonic acid) or HEPES (2-(4-(2-Hydroxyethyl)-1-piperazinyl) ethanesulfonic acid) buffer in the dark because of high autoreduction rate of Fe(Ⅲ) in the presence of light. However, the exclusion of light is inconvenient, especially when analyzing a large number of samples. The objective of this study was to develop a new method for determination of root reductase activity under normal laboratory conditions using a suitable buffer composition and Fe(Ⅲ) concentration to eliminate the autoreduction of Fe(Ⅲ). A modified method using a Tris (2-amino-2-hydroxymethyl-1,3-propanediol) buffer at pH 7.5 instead of MES or HEPES buffer and a decreased FeEDTA (Fe ethylene diamine tetraacetic acid) concentration of 50μmol L-1 was developed. The autoreduction of Fe(Ⅲ) using the Tris buffer was undetectable for temperatures at 4 and 28 ℃ and was also much lower than that using the other buffers even with sunlight during measurement of Fe(Ⅲ) reduction. Furthermore, the differences in Fe(Ⅲ) reductase activity among 5 plant species and 14 red clover cultivars (Trifolium pratense L.) could be easily detected with the modified method. The method developed in this study to measure root Fe chelate reductase activity was not only effective and reliable but also easily managed under normal laboratory light conditions. |
| Key Words: autoreduction, buffers, root Fe(Ⅲ) chelate reductase activity |
| Citation: Zheng, S. J., He, Y. F., Tang, C. X. and Masaoka, Y. 2005. A modified method for measuring root iron reductase activity under normal laboratory conditions. Pedosphere. 15(3): 363-368. |
|
View Full Text
|
|
|
|
