Plant Physiol. Illumina
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

Plant Physiology Preview
Published on June 20, 2008; 10.1104/pp.108.121459

OPEN ACCESS ARTICLE
This Article
Free via Open Access: OA
Right arrow Full Text (Plant Physiology Preview (PDF))
Right arrow Supplemental Data
Right arrowOA All Versions of this Article:
147/4/1936    most recent
pp.108.121459v2
pp.108.121459v1
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 Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Web of Science (5)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Flores, T.
Right arrow Articles by Polacco, J. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Flores, T.
Right arrow Articles by Polacco, J. C.
Agricola
Right arrow Articles by Flores, T.
Right arrow Articles by Polacco, J. C.

Received April 17, 2008
Accepted June 5, 2008

Arginase-negative mutants of Arabidopsis exhibit increased NO signaling in root development

Teresita Flores , Christopher D. Todd , Alejandro Tovar-Mendez , Preetinder K Dhanoa , Natalia Correa-Aragunde , Mary Elizabeth Hoyos , Disa M. Brownfield , Robert T. Mullen , Lorenzo Lamattina , and Joe C. Polacco *

Biochemistry Department, 117 Schweitzer Hall, University of Missouri, Columbia, MO 65211; Department of Biology, 112 Science Place, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada; Room 4470 Science Complex, 488 Gordon Street, University of Guelph, Guelph, ON, N1G 2W1, Canada; Instituto de Investigaciones Biologicas, Universidad Nacional de Mar del Plata, Funes 3250, Mar del Plata (7600) Argentina; Department of Biological Sciences, Room: CW 468, Biological Sciences Bldg., University of Alberta, Edmonton, AB, Canada T6G 2E9; Departments of Biophysics & Center of Biotechnology, Univ. Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil (CEP 91.501-970)

* Corresponding author; email: polaccoj{at}missouri.edu.

Mutation of either arginase structural gene (ARGAH1 or ARGAH2) resulted in increased formation of lateral and adventitious roots in Arabidopsis seedlings and increased nitric oxide (NO) accumulation and efflux, detected by the fluorogenic traps, DAF FM-DA and DAR-4M, respectively. Upon seedling exposure to the synthetic auxin naphthalene acetic acid, NO accumulation was differentially enhanced in argah1-1 and argah2-1 compared to wild type. In all genotypes much DAF FM-DA fluorescence originated from mitochondria. The arginases are both localized to the mitochondrial matrix and are closely related. However, their expression levels and patterns differ: ARGAH1 encoded the minor activity, and ARGAH1-driven GUS was expressed throughout the seedling; the ARGAH2::GUS expression pattern was more localized. Naphthalene acetic acid increased seedling lateral root numbers (total lateral roots per primary root) in the mutants to twice the number in the wild type- patterns consistent with increased internal NO leading to enhanced auxin signaling in roots In agreement, argah1-1 and argah2-1 showed increased expression of the auxin-responsive reporter, DR5::GUS, in root tips, emerging lateral roots and hypocotyls. We propose that arginine, or an arginine derivative, is a potential NO source, and that reduced arginase activity in the mutants results in greater conversion of Arg to NO, thereby potentiating auxin action in roots. The model is supported by supplemental arginine induction of both adventitious roots and of increased NO accumulation in argah1-1 and argah2-1 versus wild type.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
ASPB Publications PLANT PHYSIOLOGY® THE PLANT CELL
Copyright © 2008 by the American Society of Plant Biologists