Expression Profiles of 10,422 Genes at Early Stage of Low Nitrogen Stress in Rice Assayed using a cDNA Microarray
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Xingming Lian(1), Shiping Wang(1), Jianwei Zhang(1), Qi Feng(2), Lida Zhang(1), Danlin Fan(2), Xianghua Li(1), Dejun Yuan(1), Bin Han(2) and Qifa Zhang(1)
(1) National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
(2) National Center for Gene Research, Chinese Academy of Sciences, Shanghai, 200233, China
13 April 2005 Accepted:
18 July 2005
Plant Molecular Biology
Publisher: Springer Netherlands
ISSN: 0167-4412 (Paper) 1573-5028 (Online)
Issue: Volume 60, Number 5
Date: March 2006
Pages: 617 - 631
Development of crop varieties with high nitrogen use efficiency (NUE) is imperative for sustainable agriculture. Understanding how plant genes respond to low N stress is essential for formulating approaches to manipulating genes for improving NUE. In this study we analyzed the expression profiles of an indica rice cultivar Minghui 63 at seedling stage at 20 min, 1 and 2 h after low N stress with the normal N as the control, using a microarray of 11,494 rice ESTs representing 10,422 unique genes. While no significant difference was detected in the leaf tissue, a total of 471 ESTs were detected as responsive to low N stress in the root tissue with 115 ESTs showing up-regulation and 358 ESTs showing down-regulation. The analysis of expression profiles after low N stress identified following patterns: (1) the genes involved in photosynthesis and energy metabolism were down-regulated rapidly; (2) many of the genes involved in early responses to biotic and abiotic stresses were up-regulated while many other stress responsive genes were down-regulated; (3) regulatory genes including transcription factors and ones involved in signal transduction were both up- and down-regulated; and (4) the genes known to be involved in N uptake and assimilation showed little response to the low N stress. The challenges for future studies are to characterize the functional roles of the low N stress responsive genes in N metabolisms, including the large number of genes presently with unknown functions.
Electronic Supplementary Material Supplementary material is available for this article at http://dx.doi.org/10.1007/s11103-005-5441-7 and is accessible for authorized users.
Keywords cDNA chip - ESTs - nitrogen use efficiency (NUE) - Oryza sativa L