OPEN ACCESS ARTICLE

This Article Free via Open Access: OA OA Full Text Full Text (PDF) Supplemental Data OA All Versions of this Article: 151/2/755    most recent pp.109.140996v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in Plant Physiol. Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Google Scholar Articles by Zhao, M.-G. Articles by Zhang, W.-H. PubMed PubMed Citation Articles by Zhao, M.-G. Articles by Zhang, W.-H. Agricola Articles by Zhao, M.-G. Articles by Zhang, W.-H.

ENVIRONMENTAL STRESS AND ADAPTATION TO STRESS

Nitric Reductase-Dependent Nitric Oxide Production Is Involved in Cold Acclimation and Freezing Tolerance in Arabidopsis^1,[W],[OA]

State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, People's Republic of China

Nitric oxide (NO) is an important signaling molecule involved in many physiological processes in plants. We evaluated the role of NO in cold acclimation and freezing tolerance using Arabidopsis (Arabidopsis thaliana) wild type and mutants nia1nia2 (for nitrate reductase [NR]-defective double mutant) and Atnoa1/rif1 (for nitric oxide associated1/resistant to inhibition by fosmidomycin1) that exhibit defects in NR and reduced NO production, respectively. Cold acclimation induced an increase in endogenous NO production in wild-type and Atnoa1/rif1 leaves, while endogenous NO level in nia1nia2 leaves was lower than in wild-type ones and was little changed during cold acclimation. Cold acclimation stimulated NR activity and induced up-regulation of NIA1 gene expression. In contrast, cold acclimation reduced the quantity of NOA1/RIF1 protein and inhibited NO synthase (NOS) activity. These results indicate that up-regulation of NR-dependent NO synthesis underpins cold acclimation-induced NO production. Seedlings of nia1nia2 were less tolerant to freezing than wild-type plants. Pharmacological studies using NR inhibitor, NO scavenger, and NO donor showed that NR-dependent NO level was positively correlated with freezing tolerance. Furthermore, cold acclimation up- and down-regulated expression of P5CS1 and ProDH genes, respectively, resulting in enhanced accumulation of proline (Pro) in wild-type plants. The stimulation of Pro accumulation by cold acclimation was reduced by NR inhibitor and NO scavenger, while Pro accumulation by cold acclimation was not affected by the NOS inhibitor. In contrast to wild-type plants, cold acclimation up-regulated ProDH gene expression in nia1nia2 plants, leading to less accumulation in nia1nia2 plants than in wild-type plants. These findings demonstrate that NR-dependent NO production plays an important role in cold acclimation-induced increase in freezing tolerance by modulating Pro accumulation in Arabidopsis.

The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Wen-Hao Zhang (whzhang{at}ibcas.ac.cn).

^[W] The online version of this article contains Web-only data.

^[OA] Open Access articles can be viewed online without a subscription.

www.plantphysiol.org/cgi/doi/10.1104/pp.109.140996

^* Corresponding author; e-mail whzhang{at}ibcas.ac.cn.

Received May 6, 2009; accepted August 19, 2009; published August 26, 2009.

Related articles in Plant Physiol.:

On the Inside

Peter V. Minorsky
Plant Physiol. 2009 151: 481-482. [Full Text]