Genetics, Vol 138, 855-863, Copyright © 1994

INVESTIGATIONS

The Maize NCS2 Abnormal Growth Mutant Has a Chimeric nad4-nad7 Mitochondrial Gene and Is Associated With Reduced Complex I Function

J. R. Marienfeld and K. J. Newton
Present address: Institut fur Genbiologische Forschung, Ihnestra{szlig}e 63, 14195 Berlin, Federal Republic of Germany.

The molecular basis of the maternally inherited, heteroplasmic NCS2 mutant of maize was investigated. Analysis of the NCS2 mtDNA showed that it closely resembles the progenitor cmsT mitochondrial genome, except that the mutant genome contains a fused nad4-nad7 gene and is deleted for the small fourth exon of nad4. The rearrangement has occurred at a 16-bp repeat present in the third intron of the nad4 gene and in the second intron of the nad7 gene. Transcripts containing exon 4 of the nad4 gene are greatly reduced in mtRNA preparations from heteroplasmic NCS2 plants; larger transcripts are associated with the first three nad4 exons. Identical 5' ends of the nad4 transcripts have been mapped 396 and 247 bp upstream of the start codon in mtRNAs from both NCS2 and related non-NCS plants. The putative transcription termination signal of nad4 is deleted in mutant DNA, resulting in the production of the unique longer transcripts. The complex transcript pattern associated with nad7 is also altered in the mutant. Both nad4 and nad7 encode subunits of complex I (NADH dehydrogenase) of the mitochondrial electron transfer chain. Oxygen uptake experiments show that the functioning of complex I is specifically reduced in mitochondria isolated from NCS2 mutant plants.

This article has been cited by other articles:

				C. P. Lee, H. Eubel, N. O'Toole, and A. H. Millar Heterogeneity of the Mitochondrial Proteome for Photosynthetic and Non-photosynthetic Arabidopsis Metabolism Mol. Cell. Proteomics, July 1, 2008; 7(7): 1297 - 1316. [Abstract] [Full Text] [PDF]

				J. O. Allen, C. M. Fauron, P. Minx, L. Roark, S. Oddiraju, G. N. Lin, L. Meyer, H. Sun, K. Kim, C. Wang, et al. Comparisons Among Two Fertile and Three Male-Sterile Mitochondrial Genomes of Maize Genetics, October 1, 2007; 177(2): 1173 - 1192. [Abstract] [Full Text] [PDF]

				V. Shedge, M. Arrieta-Montiel, A. C. Christensen, and S. A. Mackenzie Plant Mitochondrial Recombination Surveillance Requires Unusual RecA and MutS Homologs PLANT CELL, April 1, 2007; 19(4): 1251 - 1264. [Abstract] [Full Text] [PDF]

				P. Cardol, M. Lapaille, P. Minet, F. Franck, R. F. Matagne, and C. Remacle ND3 and ND4L Subunits of Mitochondrial Complex I, Both Nucleus Encoded in Chlamydomonas reinhardtii, Are Required for Activity and Assembly of the Enzyme. Eukaryot. Cell, September 1, 2006; 5(9): 1460 - 1467. [Abstract] [Full Text] [PDF]

				R. T. Teixeira, C. Knorpp, and K. Glimelius Modified sucrose, starch, and ATP levels in two alloplasmic male-sterile lines of B. napus J. Exp. Bot., April 1, 2005; 56(414): 1245 - 1253. [Abstract] [Full Text] [PDF]

				E. V. Kuzmin, D. N. Duvick, and K. J. Newton A Mitochondrial Mutator System in Maize Plant Physiology, February 1, 2005; 137(2): 779 - 789. [Abstract] [Full Text] [PDF]

				D. L. Auger, A. D. Gray, T. S. Ream, A. Kato, E. H. Coe Jr., and J. A. Birchler Nonadditive Gene Expression in Diploid and Triploid Hybrids of Maize Genetics, January 1, 2005; 169(1): 389 - 397. [Abstract] [Full Text] [PDF]

				E. V. Kuzmin, O. V. Karpova, T. E. Elthon, and K. J. Newton Mitochondrial Respiratory Deficiencies Signal Up-regulation of Genes for Heat Shock Proteins J. Biol. Chem., May 14, 2004; 279(20): 20672 - 20677. [Abstract] [Full Text] [PDF]

				O. V. Karpova, E. V. Kuzmin, T. E. Elthon, and K. J. Newton Differential Expression of Alternative Oxidase Genes in Maize Mitochondrial Mutants PLANT CELL, December 1, 2002; 14(12): 3271 - 3284. [Abstract] [Full Text] [PDF]

				J. Gray, D. Janick-Buckner, B. Buckner, P. S. Close, and G. S. Johal Light-Dependent Death of Maize lls1 Cells Is Mediated by Mature Chloroplasts Plant Physiology, December 1, 2002; 130(4): 1894 - 1907. [Abstract] [Full Text] [PDF]

				B.-h. Lee, H. Lee, L. Xiong, and J.-K. Zhu A Mitochondrial Complex I Defect Impairs Cold-Regulated Nuclear Gene Expression PLANT CELL, June 1, 2002; 14(6): 1235 - 1251. [Abstract] [Full Text] [PDF]

				C. Remacle, D. Baurain, P. Cardol, and R. F. Matagne Mutants of Chlamydomonas reinhardtii Deficient in Mitochondrial Complex I: Characterization of Two Mutations Affecting the nd1 Coding Sequence Genetics, July 1, 2001; 158(3): 1051 - 1060. [Abstract] [Full Text] [PDF]

				D. L. Auger, K. J. Newton, and J. A. Birchler Nuclear Gene Dosage Effects Upon the Expression of Maize Mitochondrial Genes Genetics, April 1, 2001; 157(4): 1711 - 1721. [Abstract] [Full Text]

				M. Sabar, R. De Paepe, and Y. de Kouchkovsky Complex I Impairment, Respiratory Compensations, and Photosynthetic Decrease in Nuclear and Mitochondrial Male Sterile Mutants of Nicotiana sylvestris Plant Physiology, November 1, 2000; 124(3): 1239 - 1250. [Abstract] [Full Text]

				M. Duarte and A. Videira Respiratory Chain Complex I Is Essential for Sexual Development in Neurospora and Binding of Iron Sulfur Clusters Are Required for Enzyme Assembly Genetics, October 1, 2000; 156(2): 607 - 615. [Abstract] [Full Text]

				D. S. Lupold, A. G. F. S. Caoile, and D. B. Stern Genomic context influences the activity of maize mitochondrial cox2 promoters PNAS, September 28, 1999; 96(20): 11670 - 11675. [Abstract] [Full Text] [PDF]

				F. Duby and R. F. Matagne Alteration of Dark Respiration and Reduction of Phototrophic Growth in a Mitochondrial DNA Deletion Mutant of Chlamydomonas Lacking cob, nd4, and the 3' End of nd5 PLANT CELL, January 1, 1999; 11(1): 115 - 126. [Abstract] [Full Text]

				S. Gutierres, M. Sabar, C. Lelandais, P. Chetrit, P. Diolez, H. Degand, M. Boutry, F. Vedel, Y. de Kouchkovsky, and R. De Paepe Lack of mitochondrial and nuclear-encoded subunits of complex I and alteration of the respiratory chain in Nicotiana sylvestris mitochondrial deletion mutants PNAS, April 1, 1997; 94(7): 3436 - 3441. [Abstract] [Full Text] [PDF]