Chloroplast Fe(III) chelate reductase activity is essential for seedling viability under iron limiting conditions
Open Access
- 29 July 2008
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences of the United States of America
- Vol. 105 (30), 10619-10624
- https://doi.org/10.1073/pnas.0708367105
Abstract
Photosynthesis, heme biosynthesis, and Fe-S cluster assembly all take place in the chloroplast, and all require iron. Reduction of iron via a membrane-bound Fe(III) chelate reductase is required before iron transport across membranes in a variety of systems, but to date there has been no definitive genetic proof that chloroplasts have such a reduction system. Here we report that one of the eight members of the Arabidopsis ferric reductase oxidase (FRO) family, FRO7, localizes to the chloroplast. Chloroplasts prepared from fro7 loss-of-function mutants have 75% less Fe(III) chelate reductase activity and contain 33% less iron per microgram of chlorophyll than wild-type chloroplasts. This decreased iron content is presumably responsible for the observed defects in photosynthetic electron transport. When germinated in alkaline soil, fro7 seedlings show severe chlorosis and die without setting seed unless watered with high levels of soluble iron. Overall, our results provide molecular evidence that FRO7 plays a role in chloroplast iron acquisition and is required for efficient photosynthesis in young seedlings and for survival under iron-limiting conditions.Keywords
This publication has 52 references indexed in Scilit:
- PIC1, an Ancient Permease in Arabidopsis Chloroplasts, Mediates Iron TransportPlant Cell, 2007
- The Steap proteins are metalloreductasesBlood, 2006
- Tic21 Is an Essential Translocon Component for Protein Translocation across the Chloroplast Inner Envelope MembranePlant Cell, 2006
- Light-Regulated, Tissue-Specific, and Cell Differentiation-Specific Expression of the Arabidopsis Fe(III)-Chelate Reductase Gene AtFRO6Plant Physiology, 2006
- A gene expression map of Arabidopsis thaliana developmentNature Genetics, 2005
- Genome-Wide Insertional Mutagenesis of Arabidopsis thalianaScience, 2003
- Ferrous Ion Transport across Chloroplast Inner Envelope MembranesPlant Physiology, 2002
- Trafficking of Phosphatidylinositol 3-Phosphate from the trans-Golgi Network to the Lumen of the Central Vacuole in Plant CellsPlant Cell, 2001
- MMM1 encodes a mitochondrial outer membrane protein essential for establishing and maintaining the structure of yeast mitochondria.The Journal of cell biology, 1994
- A Revised Medium for Rapid Growth and Bio Assays with Tobacco Tissue CulturesPhysiologia Plantarum, 1962