The expression of a peroxiredoxin antioxidant gene, AtPer1, in Arabidopsis thaliana is seed-specific and related to dormancy

摘要

A gene, AtPer1, was isolated from the dicotyledon Arabidopsis thaliana, which shows similarity to the 1-cysteine (1-Cys) peroxiredoxin family of antioxidants. In higher plants, members of this group of antioxidants have previously only been isolatedfrom monocotyledons. It has been suggested that seed peroxiredoxins protect tissues from reactive oxygen species during desiccation and early imbibition and/or are involved in the maintenance of protection during dormancy. AtPer1 expression is restricted to seeds. Despite differences in seed development between monocots and dicots, AtPer1 showed an expression pattern during seed development and germination similar to the dormancy-related transcript Per1 in barley. In situ hybridization identified AtPer1 as the first aleurone-expressed transcript characterized in developing Arabidopsis seeds. The transcript was also expressed in the embryo. AtPer1 expression in seeds was unaltered in an abscisic acid (ABA)-deficient mutant (aba1) during seed development, while expression in seeds of an ABA-insensitive mutant (abi3-1) was reduced. The transcript was not induced in vegetative tissue in response to stress by ABA or drought. AtPer1 transcript levels are correlated to germination frequencies of wild-type seeds, but AtPer1 transcript abundance was not sufficient for expression of dormancy in non-dormant mutants. Hypotheses on peroxiredoxin function are discussed in view of the results presented. Nucleotide sequence data have been submitted to the EMBL/GenBank/DDBJ databases under the accession number Y12089.