Arabidopsis AtMPV17, a homolog of mice MPV17, enhances osmotic stress tolerance.

Abstract

Mutation in the human MPV17 gene or the functional yeast orthologue SYM1 result in mitochondrial DNA depletion. MPV17 homologs are also found in plants including Arabidopsis, but the function of these genes remain unclear. Arabidopsis genome contains 10 MPV17 homologs. Among these, the AtMPV17 protein was localized in mitochondria as MPV17 and SYM1. The yeast sym1 knock out mutant cannot grow on ethanol-containing medium at 37°C. AtMPV17 complements the ethanol growth defection of sym1 yeast MPV17 ortholog cells at 37°C, suggesting that AtMPV17 is a functional ortholog of SYM1. AtMPV17 knock out mutant, atmpv17 show similar growth and seed development to those of the wild-type plant on normal growth condition. However, atmpv17 mutant is more sensitive to ABA and mannitol during germination and seedling growth than wild type plants. Growth retardation of the atmpv17 knock out mutant on medium containing ABA and mannitol is complemented by AtMPV17 overexpression. These results suggest that the AtMPV17 contributes to osmotic stress tolerance in plants.