Defective splicing of the first nad4 intron is associated with lack of several complex I subunits in the Nicotiana sylvestris NMS1 nuclear mutant

Plant J. 2000 Feb;21(3):269-80. doi: 10.1046/j.1365-313x.2000.00679.x.


In this work, we provide evidence for the existence of a nuclear factor involved in the splicing of a specific mitochondrial intron in higher plants. In the Nicotiana sylvestris nuclear NMS1 mutant, defective in both vegetative and reproductive development, the first intron of the nad4 transcript encoding the complex I NAD4 subunit is not removed, whatever the tissue analysed. Transcript patterns of other standard mitochondrial genes are not affected in NMS1. However, numerous polypeptides are missing in two-dimensional in organelle mitochondrial protein synthesis patterns and several nuclear and mitochondrial complex I subunits are present in trace amounts. This indicates that translational or post-translational steps in the synthesis of other mitochondrial proteins are affected. All of these defects co-segregated with the abnormal phenotype in the offspring of a NMS1 x wild-type cross, showing that they are controlled by the same nuclear gene (MS1) or tightly linked loci. Such a complex situation has been described in chloroplasts and mitochondria of fungi, but never in higher plant mitochondria.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alternative Splicing*
  • Cell Nucleus / genetics
  • Cell Nucleus / metabolism
  • Crosses, Genetic
  • Gene Expression Regulation, Plant*
  • Introns
  • Mitochondria / genetics
  • Mitochondria / metabolism*
  • Monosaccharide Transport Proteins / genetics*
  • NADH Dehydrogenase / chemistry
  • NADH Dehydrogenase / genetics*
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • Plant Proteins / genetics*
  • Plants, Toxic*
  • Tobacco / enzymology
  • Tobacco / genetics*
  • Tobacco / physiology
  • Transcription, Genetic


  • MST1 protein, Nicotiana tabacum
  • Monosaccharide Transport Proteins
  • Nuclear Proteins
  • Plant Proteins
  • NADH Dehydrogenase