title: Expression of a yeast RNase III gene in transgenic tobacco silences host nitrite reductase genes.
abstract: When a gene encoding the Schizosaccharomyces pombe dsRNA-specific RNase III, pac1, was expressed in transgenic tobacco plants, six out of thirteen transformed plants gave progeny among which were individuals displaying a distinctive chlorotic phenotype. These chlorotic plants strongly resemble those transformed with a 35S-Nii (nitrite reductase) transgene, in which both Nii host genes and the 35S-Nii transgene are silenced by co-suppression. RNA blots showed that the host Nii genes were silenced in chlorotic 35S-pac1 plants but not in individuals with a normal green phenotype. Neither the transcript levels of the other cellular genes tested nor the transcription of Nii genes was significantly affected by the expression of pac1. This is the first observation of post-transcriptional silencing of host genes by a transgene with no apparent sequence similarity to the target gene.
authors.affiliation: Laboratoire de Biologie Cellulaire, INRA-Versailles, France.
authors.forename: R
authors.initials: R
authors.lastname: Berthomé
authors.forename: P Y
authors.initials: PY
authors.lastname: Teycheney
authors.forename: J P
authors.initials: JP
authors.lastname: Renou
authors.forename: Y
authors.initials: Y
authors.lastname: Okada
authors.forename: M
authors.initials: M
authors.lastname: Tepfer
mesh_terms: D004722:Endoribonucleases / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic; D020868:Gene Silencing; D005800:Genes, Fungal / Q000235:genetics; D009572:Nitrite Reductases / Q000235:genetics*; D010641:Phenotype; D010935:Plant Diseases / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics; D030821:Plants, Genetically Modified; D010947:Plants, Toxic; D043244:Ribonuclease III; D012568:Schizosaccharomyces / Q000201:enzymology*; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics*; D014158:Transcription, Genetic / Q000235:genetics; D019076:Transgenes
chemical_list: D010940:Plant Proteins; D009572:Nitrite Reductases; D004722:Endoribonucleases; D043244:Ribonuclease III