Suppression of cytoplasmic male sterility by nuclear genes alters expression of a novel mitochondrial gene region.
AUTOR(ES)
Singh, M
RESUMO
To identify regions of the mitochondrial genome that potentially could specify the "Polima" (pol) cytoplasmic male sterility (CMS) of Brassica napus, transcripts of 14 mitochondrial genes from nap (male fertile), pol (male sterile), and nuclear fertility-restored pol cytoplasm plants were analyzed. Transcriptional differences among these plants were detected only with the ATPase subunit 6 (atp6) gene. Structural analysis of the atp6 gene regions of pol and nap mitochondrial DNAs showed that rearrangements in the pol mitochondrial genome occurring upstream of atp6 have generated a chimeric 224-codon open reading frame, designated orf224, that is cotranscribed with atp6. In CMS plants, most transcripts of this region are dicistronic, comprising both orf224 and atp6 sequences. Nuclear restorer genes at either of two distinct loci appear to specifically alter this transcript pattern such that monocistronic atp6 transcripts predominate. The differences in expression of this region appear to result, in part, from differential processing of a tRNA-like element comprising a tRNA pseudogene present immediately upstream of atp6 in both the sterile and fertile mitochondrial DNAs. Possible mechanisms by which expression of the orf224/atp6 locus and the Polima CMS trait may be specifically related are considered.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=160097Documentos Relacionados
- Nuclear restoration of cytoplasmic male sterility in sunflower is associated with the tissue-specific regulation of a novel mitochondrial gene.
- Restorer genes for different forms of Brassica cytoplasmic male sterility map to a single nuclear locus that modifies transcripts of several mitochondrial genes
- Mitochondrial Complementation and Cytoplasmic Male Sterility in Wheat
- One-step generation of cytoplasmic male sterility by fusion of mitochondrial-inactivated tomato protoplasts with nuclear-inactivated Solanum protoplasts.
- RNA editing of transcripts of a chimeric mitochondrial gene associated with cytoplasmic male-sterility in Brassica.