This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 19/4/1376    most recent tpc.106.043992v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Eastmond, P. J. Search for Related Content PubMed PubMed Citation Articles by Eastmond, P. J. Agricola Articles by Eastmond, P. J.

MONODEHYROASCORBATE REDUCTASE4 Is Required for Seed Storage Oil Hydrolysis and Postgerminative Growth in Arabidopsis^[W]

Warwick HRI, University of Warwick, Wellesbourne, Warwickshire, CV35 9EF, United Kingdom

¹ To whom correspondence should be addressed. E-mail p.j.eastmond{at}warwick.ac.uk; fax 44-2476574500.

Hydrogen peroxide is a major by-product of peroxisomal metabolism and has the potential to cause critical oxidative damage. In all eukaryotes, catalase is thought to be instrumental in removing this H₂O₂. However, plants also contain a peroxisomal membrane–associated ascorbate-dependent electron transfer system, using ascorbate peroxidase and monodehydroascorbate reductase (MDAR). Here, I report that the conditional seedling-lethal sugar-dependent2 mutant of Arabidopsis thaliana is deficient in the peroxisomal membrane isoform of MDAR (MDAR4). Following germination, Arabidopsis seeds rely on storage oil breakdown to supply carbon skeletons and energy for early seedling growth, and massive amounts of H₂O₂ are generated within the peroxisome as a by-product of fatty acid ß-oxidation. My data suggest that the membrane-bound MDAR4 component of the ascorbate-dependent electron transfer system is necessary to detoxify H₂O₂, which escapes the peroxisome. This function appears to be critical to protect oil bodies that are in close proximity to peroxisomes from incurring oxidative damage, which otherwise inactivates the triacylglycerol lipase SUGAR-DEPENDENT1 and cuts off the supply of carbon for seedling establishment.

This article has been cited by other articles:

				B. S. Zheng, E. Ronnberg, L. Viitanen, T. A. Salminen, K. Lundgren, T. Moritz, and J. Edqvist Arabidopsis sterol carrier protein-2 is required for normal development of seeds and seedlings J. Exp. Bot., September 1, 2008; 59(12): 3485 - 3499. [Abstract] [Full Text] [PDF]

				J. Catusse, J.-M. Strub, C. Job, A. Van Dorsselaer, and D. Job Proteome-wide characterization of sugarbeet seed vigor and its tissue specific expression PNAS, July 22, 2008; 105(29): 10262 - 10267. [Abstract] [Full Text] [PDF]