Mitochondria have an essential role in a variety of metabolic pathways as well as in complex fundamental processes such as development, programmed cell death, and aging. The integration of mitochondrial function within plant cellular metabolism requires the controlled exchange of various molecules, mediated by transport protein complexes. On pages 89100 of this issue, Kushnir et. al., describe the chlorotic, dwarfish Arabidopsis mutant STARIK, which is deficient in the mitochondrial ABC transporter Sta1. Analysis of the mutant and complementation experiments in yeast indicates the importance of plant mitochrondria in intracellular iron homeostasis and Fe/S cluster biogenesis. Mitochondrial dysfunction in sta1 cells leads to an unusual nuclear gene response, which might represent a case of retrograde regulation from mitochondria to the nucleus. The cover shows a fluorescent confocal image of a single live tobacco protoplast expressing the Sta1-GFP fusion protein, which is localized exclusively in the mitochondria (green). Chlorophyll autofluorescence in the chloroplasts is seen as magenta.
[Table of Contents]
