Skip Navigation



Plant and Cell Physiology Advance Access published online on February 5, 2008
Plant and Cell Physiology, doi:10.1093/pcp/pcn017
This Article
Right arrow Advance Access manuscript (PDF)
Right arrow Supplementary Data
Right arrow All Versions of this Article:
49/3/411    most recent
pcn017v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Zhang, L. P.
Right arrow Articles by Yang, Z. M.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Zhang, L. P.
Right arrow Articles by Yang, Z. M.
Agricola
Right arrow Articles by Zhang, L. P.
Right arrow Articles by Yang, Z. M.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2008. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For Permissions, please e-mail: journals.permissions@oxfordjournals.org

Copper-induced proline synthesis is associated with nitric oxide generation in Chlamydomonas reinhardtii

Li Ping Zhang1,2, Surya Kant Mehta1,*, Zhao Pu Liu2 and Zhi Min Yang1,**

1Department of Biochemistry and Molecular Biology, College of Life Science, 2Key Lab of Marine Biology in Jiang Su, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China.

**Corresponding author: Prof. Zhi Min Yang. College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China. Telephone number: 86-25-84395057, Email: zmyang{at}njau.edu.cn


  Abstract

Excess copper affects the growth and metabolism of plants and green alga. However, the physiological processes under the Cu stress are largely unknown. In this study, we investigated Cu-induced nitric oxide generation and its relation to proline synthesis in Chlamydomonas reinhardtii. The test alga accumulated a large amount of proline after exposure to relatively low Cu concentrations (2.5 and 5.0 µM Cu2+). Concomitant increase in intracellular nitric oxide (NO) level was observed with increasing concentrations of Cu applied. Data analysis reveals that endogenous NO generated was positively associated with the proline level in Cu-stressed alga. The involvement of NO in Cu-induced proline accumulation was confirmed by using a NO specific donor sodium nitroprusside (SNP) and a NO scavenger cPTIO [2-(4-carboxy-2-phenyl)-4,4,5,5 -tetramethylinidazoline-1 -oxyl-3-oxide]. Pre-treatment with 10 µM SNP increased the proline accumulation in Cu-treated cells by about 1.5-folds, while this effect could be blocked by addition of 10 µM cPTIO. We further investigated the effect of Cu and NO on the activity and transcript amount of {Delta}1-pyrroline-5-carboxylate synthetase (P5CS, EC 2.7.2.11 [EC] ), the key enzyme of proline biosynthesis, and observed that application of SNP was able to stimulate the P5CS activity and upregulate the expression of P5CS in the Cu-treated algae. These results indicate that the copper-responsive proline synthesis is closely related to the nitric oxide generation in C. reinhardtii, suggesting the regulatory function of NO in proline metabolism under the heavy metal stress.

Keywords: copper - nitric oxide - proline - Chlamydomonas reinhardtii

*These authors contributed equally to this work

(Received November 11, 2007; Accepted January 28, 2008)
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.