RESEARCH INTERESTS:

The mitochondrion is the cellular site of energy metabolism in all eukaryotes. It contains its own genetic information, which is transmitted maternally in most higher eukaryotes. Our research focuses on the genetic processes that regulate mitochondrial DNA replication, recombination, repair and transmission to progeny. Because the mitochondrion is so essential to cellular function, these questions are of fundamental importance. From an agricultural perspective, however, we find that mitochondrial genetic information influences several traits of agronomic importance including male sterility, plant vigor, chloroplast function, and cross-compatibility.

MAJOR PROJECT ACTIVITIES:

Our laboratory is involved in four primary research projects currently:

1. We seek to understand the role of several nuclear genes in the maintenance and transmission of mitochondrial DNA.
2. We investigate the role of epigenetic gene regulation in cytoplasmic-nuclear genetic interactions during embryogenesis.
3. The laboratory has evidence to suggest that mitochondrial protein export of a particular mutant protein may occur in plants (Abad et al. 1995; He et al. 1996). We pursue this phenomenon utilizing Arabidopsis as a model system with mutation strategies to identify protein features important to the protein export process.
4. Particular nuclear genes regulating mitochondrial genome maintenance also target their proteins to the chloroplast. We study the dual function of such proteins in these two cellular compartments.

SELECTED PUBLICATIONS:

• Abdelnoor, R.V., Yule, R., Elo, A., Christensen, A., Meyer-Gauen, G. and Mackenzie, S. 2003 Substoichiometric Shifting in the Plant Mitochondrial Genome is influenced by a Gene Homologous to MutS. Proc. Natl Acad. Sci. USA 100(10):5968-5973.
  
  
• Elo, A., Lyznik, A., Gonzalez, D.O., Kachman, S.D. and Mackenzie, S. 2003. Nuclear genes encoding mitochondrial proteins for DNA and RNA metabolism are clustered in the Arabidopsis genome. Plant Cell, in press, July issue.
  
  
• Vaghchhipawala, Z., Bassuner, R., Clayton, K., Lewers, K., Shoemaker, R., and Mackenzie, S. 2001. Modulations in gene expression and mapping of genes associated with cyst nematode infection in soybean. MPMI 14:42-54.
  
  
• Arrieta-Montiel, M., Lyznik, A., Woloszynska, M., Janska, H., Tohme, J., Mackenzie, S. 2001. Tracing evolutionary and developmental implications of mitochondrial genomic shifting in the common bean. Genetics 158:851-864.
  
  
• Astua-Monge, G., Lyznik, A., Jones, V., Mackenzie, S. and Vallejos, C.E. 2001. Evidence for a prokaryotic insertion sequence contamination in eukaryotic sequences registered in different databases. Theor. Appl. Genet. 104(1):48-53.
  
  
• Vanhouten, W. and Mackenzie, S. 2000. In pursuit of a nuclear factor influencing mitochondrial genome configuration in a higher plant. Stadler Symposium Proceedings, pp 91-98.
  
  
• Mackenzie, S. and McIntosh, L. 1999. Higher Plant Mitochondria. Plant Cell 11:571-585.
  
  
• Vanhouten, W. and Mackenzie, S. 1999. Construction and characterization of a common bean bacterial artificial chromosome library. Plant Molec. Biol. 40:977-983.
  
  
• Sarria, R., Lyznik, A., Vallejos, C.E. and Mackenzie, S. 1998 A cytoplasmic male sterility-associated mitochondrial peptide in common bean is posttranslationally regulated. Plant Cell 10:1217-1228.
  
  
• Janska, H., Sarria, R., Woloszynska, M., Arrieta-Montiel, M. and Mackenzie, S. 1998. Stoichiometric shifts in the common bean mitochondrial genome leading to male sterility and spontaneous reversion to fertility. Plant Cell 10:1163-1180.
  
  
• Leon, P., Arroyo, A. and Mackenzie, S. 1998. Nuclear control of plastid and mitochondrial development in higher plants. Annu. Rev. Plant Physiol. Plant Mol. Biol. 49:453-480.
  
  
• Sarria, R., Janska, H., Arrieta-Montiel, M., Lyznik, A., and Mackenzie, S. 1998. Two nuclear-directed means of suppressing a dominant mitochondrial mutation in common bean. J. Hered 90:357-361.
  
  
• He, S., Abad, A., Gelvin, S. and Mackenzie, S. 1996. A cytoplasmic male sterility-associated mitochondrial protein causes pollen disruption in transgenic tobacco. Proc. Natl. Acad. Sci. USA, 93:11763-11768.
  
  
• He*, S., Lyznik, A. and Mackenzie*, S. 1995. Pollen fertility restoration by nuclear gene Fr in cms bean: Nuclear-directed alteration of a mitochondrial population. Genetics 139:955-962.
  
  
• Abad*, A., Mehrtens, B. and Mackenzie*, S. 1995. Specific expression and fate of a mitochondrial sterility-associated mitochondrial protein in cms common bean. Plant Cell 7:271-285.