title: The Arabidopsis PEX12 gene is required for peroxisome biogenesis and is essential for development.
abstract: Peroxisomes perform diverse and vital functions in eukaryotes, and abnormalities in peroxisomal function lead to severe developmental disorders in humans. Peroxisomes are also involved in a wide array of physiological and metabolic functions unique to plants, yet many aspects of this important organelle are poorly understood. In yeast and mammals, various steps in peroxisome biogenesis require the function of peroxin (PEX) proteins, among which PEX12 is a RING finger peroxisomal membrane protein involved in the import of matrix proteins. To investigate the role of PEX12 in plants, we identified a T-DNA knockout allele of PEX12 and generated partial loss-of-function pex12 mutants using RNA interference. We show that pex12 null mutants are developmentally arrested during early embryogenesis, and that the embryo-lethal phenotype can be rescued by overexpression of the PEX12-cyan fluorescent protein fusion protein, which targets to the peroxisome. Using virus-induced gene-silencing techniques, we demonstrate that peroxisomal number and fluorescence of the yellow fluorescent protein-peroxisome targeting signal type 1 protein are greatly reduced when PEX12 is silenced. RNA interference plants with partial reduction of the PEX12 transcript exhibit impaired peroxisome biogenesis and function, inhibition of plant growth, and reduced fertility. Our work provides evidence that the Arabidopsis (Arabidopsis thaliana) PEX12 protein is required for peroxisome biogenesis and plays an essential role throughout plant development.
authors.affiliation: Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, 48824, USA.
authors.forename: Jilian
authors.initials: J
authors.lastname: Fan
authors.forename: Sheng
authors.initials: S
authors.lastname: Quan
authors.forename: Travis
authors.initials: T
authors.lastname: Orth
authors.forename: Chie
authors.initials: C
authors.lastname: Awai
authors.forename: Joanne
authors.initials: J
authors.lastname: Chory
authors.forename: Jianping
authors.initials: J
authors.lastname: Hu
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D008565:Membrane Proteins / Q000737:chemistry / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D009154:Mutation; D000074401:Peroxins; D020675:Peroxisomes / Q000378:metabolism*; D010641:Phenotype; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D029681:Arabidopsis Proteins; D008565:Membrane Proteins; D000074401:Peroxins; C507147:peroxin 12 protein, Arabidopsis