Dr. David Rhoads
B.S., The Pennsylvania State University
Ph.D., Michigan State University
BIOL 300 - Cell Physiology
BIOL 431 - Comparative Plant Physiology
BIOL 490B - Microbial Genomics and Molecular Biotechnology
BIOL 491A - Original Research in Microbial Genomics
Regulation of nuclear gene expression by mitochondria in plants
The research program in my lab is focused on two primary areas that are part of the emerging field of inter-organellar communication in plants: 1) defining the basic molecular and cellular aspects of the control of nuclear gene expression by plant mitochondria, which is called mitochondrial retrograde regulation (MRR); and 2) determining the extent to which MRR contributes to responses of plants to stresses. My group has developed systems to study each of these areas using biochemical, molecular, genetic, and genomic approaches.
In plants, mitochondrial dysfunction can result in death at the embryo stage, inhibition of growth, chlorosis, and decreased fertility. Perturbation of mitochondrial functions leads to altered nuclear gene expression through MRR. Mechanisms, gene targets and outcomes of plant MRR are poorly understood. The overarching hypothesis in the lab is that many environmental stresses cause mitochondrial perturbations and that this results in MRR, which contributes to the ensuing stress responses in plants. If a stress affects mitochondria and signals from mitochondria influence nuclear gene expression (mitochondria as stress sensors), then this is stress-response-associated MRR, which, we hypothesize, is part of general stress signaling. Evidence, including from our research, suggests that mitochondrial status and MRR play roles in responses to both abiotic and biotic stresses and several lines of evidence strongly suggest that there are multiple MRR pathways in plants.
Thus, the overall goals of research in my lab are to 1) identify MRR signaling pathways in plants; 2) identify molecular mechanisms and components of MRR; and 3) determine the contributions of MRR to abiotic and biotic stress responses, including gene targets.
I am also part of a national consortium of university educators involved in an initiative, called Guiding Education through Novel Investigation (GENI), devoted to developing original research projects for undergraduate and high school classrooms (see geni-science.org). The projects that we developed in functional microbial genomics use amino acid biosynthetic pathways as the model system and lend themselves well to training undergraduates and high school students (through research partnerships with high school science teachers) in microbial biology, biotechnology, molecular biology, genetics and genomics through application of critical thinking, scientific reasoning and problem solving. Because of our long-standing emphasis on involving undergraduates in original research, several undergraduates who participated in these projects (as well as in my lab, in general) are authors on published papers. Our aim is to expand the number of students involved in original research projects in order to improve undergraduate and high school science education through greater engagement of students.
Slater S, Setubal JC, Goodner B, Houmiel K, Sun J, Kaul R, Goldman BS, Farrand SK, Almeida Jr. N, Burr T, Nester E, Rhoads DM, Kadoi R, Ostheimer T, Pride N, Sabo A, Henry E, Telepak E, Cromes L, Harkleroad A, Oliphant L, Pratt-Szegila P, Welch R, Wood D. (2013) The Genome of Agrobacterium tumefaciens C58: Reconciliation of sequence data, updated annotation, and distribution of linear chromosome in genus Agrobacterium. Applied Environ. Microbiol. 79: 1414-1417.
Umbach AL, Zarkovic J, Yu J, Ruckle ME, McIntosh L, Hock JJ, Bingham S, White SJ, George RM, Subbaiah CC, Rhoads DM. (2012) Comparison of Intact Leaf Transcript Profiles During Treatment with Inhibitors of Mitochondrial Electron Transport and TCA Cycle. PLoS ONE 7(9): e44339. doi:10.1371/journal.pone.0044339.
Rhoads, DM (2012) Microbial Genomics: Complementation to Test Annotation of a Gene as Important for Proline Biosynthesis. In Introduction to Biotechnology II Lab Manual (Simonson NX, Logvin M, Grimes A, King S) Kendall Hunt, Dubuque, IA.
Rhoads DM (2011) Plant mitochondrial retrograde regulation. In Advances in Plant Biology (F Kempken, ed.) Springer, New York, Vol. 1, pp.439-468.
Subbaiah CC, Huber SC, Sachs MM, Rhoads D (2007). Sucrose synthase: Expanding protein function. Plant Signaling & Behavior 2: 36-37.
Rhoads DM, Subbaiah CC (2007) Mitochondrial retrograde regulation in plants. Mitochondrion 7: 177-194.
Rhoads DM, Umbach AL, Subbaiah CC, Siedow JN (2006) Mitochondrial ROS: contribution to oxidative stress and inter organellar signaling. Plant Physiol. 141: 357-366.
Dojcinovic D, Krosting J, Harris AJ, Wagner DJ, Rhoads DM (2005) Identification of regions of the Arabidopsis AtAOX1a promoter important for developmental and mitochondrial retrograde regulation of expression. Plant Mol. Biol. 158: 159-175.
Zarkovic J, Anderson SL, Rhoads DM (2005) A reporter gene system used to study developmental expression of alternative oxidase and isolate mitochondrial retrograde regulation mutants in Arabidopsis. Plant Mol. Biol. 57: 871-888
Rhoads DM, White SJ, Zhou Y, Muralidharan M, Elthon TE (2005) Altered gene expression in plants with constitutive expression of a mitochondrial small heat shock protein suggests the involvement of retrograde regulation in the heat stress response. Physiol. Plant. 123: 435-444.
Rhoads DM, Vanlerberghe GC (2004) Mitochondria-Nucleus Interactions: Evidence for mitochondrial retrograde communication in plant cells. In Advances in Photosynthesis and Respiration. DA Day, AH Millar, J Whelan, eds. Kluwer Academic Publishers, Dordrecht, The Netherlands. Vol 17, pp. 83-106.