Decreased arginine and nitrite levels in nitrate reductase-deficient Arabidopsis thaliana plants impair nitric oxide synthesis and the hypersensitive response to Pseudomonas syringae

Nitric oxide ( NO) produced in plants is implicated in defense responses against pathogens. NO synthesis in such conditions has been attributed to a nitric oxide synthase (NOS)-like enzyme and, more recently, to a mitochondrial-dependent NO 2 −-reducing activity. In this work, we used an NR-deficien...

Full description

Saved in:

Bibliographic Details
Published in:	Plant science (Limerick) Vol. 171; no. 1; pp. 34 - 40
Main Authors:	Modolo, Luzia V., Augusto, Ohara, Almeida, Irene M.G., Pinto-Maglio, Cecília A.F., Oliveira, Halley C., Seligman, Kelly, Salgado, Ione
Format:	Journal Article
Language:	English
Published:	Shannon Elsevier Ireland Ltd 01-07-2006 Elsevier Science
Subjects:	Arabidopsis thaliana arginine Biological and medical sciences biosynthesis Fundamental and applied biological sciences. Psychology Hypersensitive response l-Arginine Metabolism Nitrate reductase nitrate reductase (NADH) Nitric oxide Nitrite nitrites Nitrogen metabolism plant pathogenic bacteria Plant physiology and development Pseudomonas syringae Hypersensitive response NR EPR DAF-2DA HR Psm Nitrite Arabidopsis thaliana l-Arginine NOS Nitrate reductase NiR Nitric oxide (MGD) 2Fe(II) L-Arginine Enzyme Hypersensitivity Plant leaf Nitric-oxide synthase Chlorosis Cruciferae Dicotyledones Aminoacid Angiospermae Spermatophyta Oxidoreductases Mutation
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	Nitric oxide ( NO) produced in plants is implicated in defense responses against pathogens. NO synthesis in such conditions has been attributed to a nitric oxide synthase (NOS)-like enzyme and, more recently, to a mitochondrial-dependent NO 2 −-reducing activity. In this work, we used an NR-deficient double mutant ( nia1 nia2) of Arabidopsis thaliana that is deficient in endogenous NO 2 − to analyse the hypersensitive response (HR) against an avirulent strain of Pseudomonas syringae pv. maculicola (Psm) . The inoculation of Psm into nia1 nia2 A. thaliana caused leaf chlorosis whereas the HR was induced in wild-type plants. NO production in situ was substantially increased in wild-type but not in nia1 nia2 leaves following inoculation of Psm, as measured with the fluorescent NO indicator 4,5-diaminofluorescein diacetate. However, the infiltration of l-arginine or NO 2 − into nia1 nia2 leaves triggered NO production in situ. Moreover, co-infiltration of NO 2 − and Psm restored the HR in the leaves of nia1 nia2 plants. The total content of free amino acids, particularly l-arginine, was much lower in nia1 nia2 leaves compared to wild-type leaves. Overall, these results suggest that the HR is affected in NR-deficient plants because these plants lack l-arginine and NO 2 −, two important endogenous substrates for NO synthesis.
Bibliography:	http://dx.doi.org/10.1016/j.plantsci.2006.02.010 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23
ISSN:	0168-9452 1873-2259
DOI:	10.1016/j.plantsci.2006.02.010