Plant Physiol. Bio-Rad Microplate Reader
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

First published online September 14, 2007; 10.1104/pp.107.106336

Plant Physiology 145:691-702 (2007)
© 2007 American Society of Plant Biologists

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
145/3/691    most recent
pp.107.106336v1
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 ISI 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 HighWire
Right arrow Citing Articles via ISI Web of Science (1)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Shahbazi, M.
Right arrow Articles by Kuntz, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Shahbazi, M.
Right arrow Articles by Kuntz, M.
Agricola
Right arrow Articles by Shahbazi, M.
Right arrow Articles by Kuntz, M.
BIOENERGETICS AND PHOTOSYNTHESIS

Dual Role of the Plastid Terminal Oxidase in Tomato

Maryam Shahbazi, Matthias Gilbert, Anne-Marie Labouré and Marcel Kuntz*

Centre National de la Recherche Scientifique and Université Joseph Fourier, Laboratory Plastes et Différenciation Cellulaire, 38041 Grenoble, France (M.S., A.-M.L., M.K.); and Institut für Biologie I, Pflanzenphysiologie, Universität Leipzig, D–04103 Leipzig, Germany (M.G.)

The plastid terminal oxidase (PTOX) is a plastoquinol oxidase whose absence in tomato (Solanum lycopersicum) results in the ghost (gh) phenotype characterized by variegated leaves (with green and bleached sectors) and by carotenoid-deficient ripe fruit. We show that PTOX deficiency leads to photobleaching in cotyledons exposed to high light primarily as a consequence of reduced ability to synthesize carotenoids in the gh mutant, which is consistent with the known role of PTOX as a phytoene desaturase cofactor. In contrast, when entirely green adult leaves from gh were produced and submitted to photobleaching high light conditions, no evidence for a deficiency in carotenoid biosynthesis was obtained. Rather, consistent evidence indicates that the absence of PTOX renders the tomato leaf photosynthetic apparatus more sensitive to light via a disturbance of the plastoquinone redox status. Although gh fruit are normally bleached (most likely as a consequence of a deficiency in carotenoid biosynthesis at an early developmental stage), green adult fruit could be obtained and submitted to photobleaching high light conditions. Again, our data suggest a role of PTOX in the regulation of photosynthetic electron transport in adult green fruit, rather than a role principally devoted to carotenoid biosynthesis. In contrast, ripening fruit are primarily dependent on PTOX and on plastid integrity for carotenoid desaturation. In summary, our data show a dual role for PTOX. Its activity is necessary for efficient carotenoid desaturation in some organs at some developmental stages, but not all, suggesting the existence of a PTOX-independent pathway for plastoquinol reoxidation in association with phytoene desaturase. As a second role, PTOX is implicated in a chlororespiratory mechanism in green tissues.

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: Marcel Kuntz (marcel.kuntz{at}ujf-grenoble.fr).

www.plantphysiol.org/cgi/doi/10.1104/pp.107.106336

* Corresponding author; e-mail marcel.kuntz{at}ujf-grenoble.fr.

Received July 26, 2007; accepted September 10, 2007; published September 14, 2007.




This article has been cited by other articles:


Home page
 Plant Physiol.Home page
F. Busch, N. P.A. Huner, and I. Ensminger
Increased Air Temperature during Simulated Autumn Conditions Impairs Photosynthetic Electron Transport between Photosystem II and Photosystem I
Plant Physiology, May 1, 2008; 147(1): 402 - 414.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
ASPB Publications PLANT PHYSIOLOGY THE PLANT CELL
Copyright © 2007 by the American Society of Plant Biologists