Arabidopsis plants with altered levels of alternative oxidase

ABSTRACT: In higher plants, various developmental and environmental conditions enhance expression of the mitochondrial alternative oxidase (AOX). In this work transgenic Arabidopsis thaliana plants were generated that either overexpress AOX or inhibit its synthesis. Gene expression following antimycin A treatment, which inhibits the cytochrome pathway in mitochondria, was studied in an AOX overexpressor line. The role of AOX in regulation of reactive oxygen species (ROS) in leaves was studied in the transgenic lines. The transgenic lines were also used to investigate the mitochondria-chloroplasts interaction in assays performed at three-times growth light. For most of the parameters measured AOX antisense lines and WT plants showed a very similar response whereas AOX sense lines differed in several aspects. An unexpected result was that AOX overexpressors had higher cellular ATP/ADP ratios as compared to WT and antisense lines. This was linked to decreased photosynthetic CO2-assimilation and O2-evolution, closed PSII reaction centers and altered Calvin cycle metabolite contents. We conclude that increased mitochondrial AOX capacity can lead to a drain of electrons from the chloroplasts causing an unfavorable redox status and thereby inhibit photosynthesis. Keywords: Genetic modification

ORGANISM(S): Arabidopsis thaliana

PROVIDER: GSE4113 | GEO | 2006/01/31

SECONDARY ACCESSION(S): PRJNA94937

REPOSITORIES: GEO