Mining Arabidopsis late embryogenesis abundant (LEA) proteome for mitochondrial candidates.
Résumé
Late Embryogenesis Abundant (LEA) proteins are highly hydrophilic proteins that accumulate to high level during seed development. They are also found in other anhydrobiotic organisms, suggesting an important role with respect to desiccation and water stress tolerance. Two mitochondrial LEA proteins were previously characterized in pea seeds and in the brine shrimp Artemia franciscana. The mitochondrial LEA proteins were shown to contribute to stress tolerance at the cellular and organelle levels. We are interested in characterizing mitochondrial LEA proteins in the model plant Arabidopsis thaliana, to further explore their functions with genetic approaches. Since the Arabidopsis genome harbours 51 LEA protein genes, we have undertaken a detailed bioinformatic analysis to basically predict the subcellular localization and structural features of the whole set of LEA gene products. In addition to the putative orthologs of the pea mitochondrial LEA protein, several other LEA proteins were predicted with a possible mitochondrial localization. To further investigate the location of the LEA proteins, we will perform transient expression of GFP translational fusions in leaf protoplasts. This should provide additional clues to identify mitochondrial LEA proteins in Arabidopsis, and contribute to the subcellular annotation of the LEA gene family.