A reporter gene system used to study developmental expression of alternative oxidase and isolate mitochondrial retrograde regulation mutants in Arabidopsis.
Perturbation of mitochondrial function causes altered nuclear gene expression in plants. To study this response, called mitochondrial retrograde regulation, and developmental gene expression, a transgenic Arabidopsis thaliana (Col-0) line containing a firefly luciferase gene controlled by a promoter region of the Arabidopsis alternative oxidase 1a gene (AtAOX1a) was created. The transgene and the endogenous gene were developmentally induced in young cotyledons to a level higher than in older cotyledons and leaves. Analysis of transgene expression suggests that this is true for emerging leaves as well. Antimycin A (AA), a mitochondrial electron transport chain inhibitor, and monofluroacetate (MFA), a TCA cycle inhibitor, induced expression of the transgene and the endogenous gene in parallel. The following comparative responses of the transgene to inhibitors were observed: (a) the response in cotyledons to AA treatment differed greatly in magnitude from the response in leaves; (b) the induction kinetics in cotyledons following MFA treatment differed greatly from the kinetics in leaves; and (c) the induction kinetics following MFA treatment differed from the kinetics of AA in both leaves and cotyledons. The transgenic line was used in a genetic screen to isolate mutants with greatly decreased transgene and AtAOX1a induction in response to AA. Some of these mutant lines showed greatly decreased induction by MFA, but one did not. Taken altogether, the data provide genetic evidence that suggests that induction of the AtAOX1a gene by distinct mitochondrial perturbations are via distinct, but overlapping signaling pathways that are tissue specific.
Zarkovic
Jelena
J
School of Life Sciences Arizona, State University, Box 874501, Tempe, AZ 85287, USA.
Anderson
Shawn L
SL
Rhoads
David M
DM
D000968:Antimycin A / Q000494:pharmacology; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D015152:Blotting, Northern; D018548:Cotyledon / Q000235:genetics / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics; D005463:Fluoroacetates / Q000494:pharmacology; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017930:Genes, Reporter / Q000235:genetics*; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D008163:Luminescent Measurements / Q000379:methods; D008928:Mitochondria / Q000187:drug effects / Q000502:physiology*; D024101:Mitochondrial Proteins; D008954:Models, Biological; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009154:Mutation; D010088:Oxidoreductases / Q000235:genetics*; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000187:drug effects / Q000235:genetics; D017422:Sequence Analysis, DNA; D015398:Signal Transduction / Q000187:drug effects; D000099188:Alternative Oxidase
D000968:Antimycin A; D004269:DNA, Bacterial; D018744:DNA, Plant; D005463:Fluoroacetates; D008156:Luciferases; D024101:Mitochondrial Proteins; D010088:Oxidoreductases; D010940:Plant Proteins; D018749:RNA, Plant; D011993:Recombinant Fusion Proteins; D000099188:Alternative Oxidase; C036483:T-DNA; C014815:fluoroacetic acid