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Department of Plant Pathology

Richard B. Todd

richard Associate Professor
1712 Claflin Rd
4018B Throckmorton Ctr.
Kansas State University
Manhattan, KS 66506
Phone: 785-532-0962
Fax: 785-532-5692
rbtodd@ksu.edu
View My Curriculum Vitae 

Area of Specialization

Molecular genetics, genomics and cell biology of nitrogen utilization and metabolic gene regulation in the fungus Aspergillus nidulans.

Biography and Education

Education

  • Ph.D. Genetics, University of Melbourne, 1998
  • B.Sc. (Hons) Genetics, University of Adelaide, 1991
  • B.Sc. Genetics, Biochemistry, University of Adelaide, 1990

Postdoctoral experience

  • Department of Genetics, University of Melbourne, 1998-2003
  • Department of Genetics, University of Adelaide, 1998
  • Biotechnology Laboratory and Department of Botany, University of British Columbia, 1996-1998

Other experience

  • Lecturer, Department of Genetics, University of Melbourne, 2003-2008
  • Research Associate, Department of Genetics, University of Melbourne, 2008-present

Staff and Students

Cameron Hunter, PhD student

Research

Research in Richard Todd’s Fungal Genetics and Genomics Lab aims to understand the molecular mechanisms regulating fungal metabolic gene expression.

Our key questions are:

* How do transcription factors (proteins that control gene expression) regulate nitrogen utilization in fungi?

* How is the information encoded by nutrient metabolism genes used differentially, depending on nutrient quality and availability, to coordinate nutrient acquisition?

* What are the signaling mechanisms underlying metabolic gene regulation?

We use the filamentous fungus Aspergillus nidulans, an important genetic model for both harmful and beneficial molds, to study gene regulation. Aspergillus species are highly prevalent in nature and include important industrial species and pathogens. Industrial Aspergilli are used for production of foods (e.g. soy sauce, sake, miso), enzymes (e.g. amylases, xylanases, oxidases and proteases used for dough improvement in the baking industry), and metabolites (e.g. citric acid, lovastatin). Aspergillus species include important plant pathogens, which make carcinogenic aflatoxin that can contaminate food and feed, as well as Aspergillosis-causing pathogens of coral, birds, animals, and humans. Aspergillus nidulans is usually not pathogenic, but lives in soils and degrades a wide range of complex biological matter, using enzymes to break down these nutrients and synthesize new products.

Nitrogen nutrient availability and quality is important for fungal pathogens as they adapt to the host environment, and for industrial fungi as they break down nutrients via metabolism for biosynthesis of products of commercial value.

Our research focuses on important transcription factors involved in nitrogen regulation in Aspergillus nidulans, including AreA, TamA, NmrA, and LeuB. We aim to understand how the activity of these transcription factors is regulated to control coordinated expression of their target genes. We use a combination of genetics, molecular biology, cell biology, genomics, and biochemistry to analyze gene function. We study the molecular mechanisms underlying the following processes:

* Regulation of nitrogen metabolic gene expression and nitrogen utilization.

* Regulation of transcription factor activity.

* Control of import and export of transcription factors into the cell nucleus.

* DNA binding and DNA binding-independent functions of transcription factors.

* Leucine biosynthesis.

What is Aspergillus nidulans?

* Aspergillus nidulans is a filamentous fungus, a mold, a microbe, and a eukaryote.

* Aspergillus species can be found everywhere.

* Aspergillus nidulans generally lives in soil.

Why use Aspergillus nidulans as a model for the Aspergilli and other pathogenic fungi?

* Excellent genetics: Aspergillus nidulans is one of the best systems for studying fungi due to ~70 years of genetic analysis and the development of molecular genetics tools for gene manipulation that often are not available or as easy in other fungi.

* Conserved genes: Many of the genes and molecular mechanisms underlying common processes are conserved between Aspergillus nidulans and other fungi, including fungal pathogens.

Teaching

PLPTH 927 Fungal Genetics. 3 Cr. Spring, even years. A study of the classical, molecular, and population aspects of fungal genetics in both model and commercially important systems. Topics to be discussed include genetic analysis via mitosis and meiosis, models of recombination, genetic control of fungal development, basic molecular genetics of fungi, and genetic factors affecting fungal population structure and stability. 

Publications

Benoit, I., Zhao, M., Viva Duartes, A., Downes, D.J.1, Todd, R.B., Kloezen, W.,Post, H., Heck, A.J.R., Altelaar, A.F.M., and de Vries, R.P. (2015) Spatial differentiation in Aspergillus niger colony grown for sugar beet pulp utilization. Scientific Reports. 5:13592. doi: 10.1038/srep13592. [KAES contribution: 15-305-J]

Katz, M.E., Buckland, R., Hunter, C.C.1, and Todd, R.B. (2015) Distinct roles for the p53-like transcription factor XprG and autophagy genes in the response to starvation Fungal Genetics and Biology. 83: 10-18. doi: http://dx.doi.org/10.1016/j.fgb.2015.08.006 [KAES contribution: 15-091-J.]

Downes, D.J., Chonofsky, M., Tan, K., Pfannenstiel, B.T., Reck-Peterson, S.L., and Todd, R.B. (2014) Characterization of the mutagenic spectrum of 4-nitroquinoline oxide (4-NQO) in Aspergillus nidulans by whole genome sequencing. G3: Genes, Genomes, Genetics. 4(12): 2483-2492. [KAES contribution: 15-090-J]

Downes, D.J., Davis, M.A., Wong, K.H., Kreutzberger, S.D., Hynes, M.J. and Todd, R.B. (2014) Dual DNA binding and coactivator functions of Aspergillus nidulans TamA, a Zn(II)2Cys6 transcription factor. Molecular Microbiology 92: 1198-1211. [KAES contribution: 14-065-J]

Ostrander, J.C., Todd, R.B., and Kennelly, M.M. (2014) Characterization of resistance to thiophanate-methyl in Kansas isolates of Sclerotinia homoeocarpa. Plant Health Progress 15: 80-84. [KAES contribution: 14-063-J]

Hunter, C.C., Siebert, K.S., Downes, D.J., Wong, K.H., Kreutzberger, S.D., Fraser, J.A., Clarke, D.F., Hynes, M.J., Davis, M.A., and Todd, R.B. (2014) Multiple nuclear localization signals mediate nuclear localization of the GATA transcription factor AreA. Eukaryotic Cell 13: 527-538. [KAES contribution: 14-064-J]

Todd, R.B., Zhao, M., Ohm, R.A., Leeggangers, H.A.C.F., Visser, L., and de Vries, R.P. (2014) Prevalence of transcription factors in ascomycete and basidiomycete fungi. BMC Genomics 15: 214. [KAES contribution: 14-055-J].

Downes, D.J., Davis, M.A., Kreutzberger, S.D., Taig, B.L., and Todd, R.B. Regulation of the NADP-glutamate dehydrogenase gene gdhA in Aspergillus nidulans by the Zn(II)2Cys6 transcription factor LeuB. Microbiology 159: 2467-2480. [KAES Contribution No. 14-008-J]

Makita, T., Katsuyama, Y., Tani, S., Suzuki, H., Kato, N., Todd, R.B., Hynes, M.J., Tsukagoshi, N., Kato, M. and Kobayashi, T. 2009. Inducer-dependent nuclear localization of a Zn(II)2Cys6 transcriptional activator, AmyR, in Aspergillus nidulans. Bioscience, Biotechnology and Biochemistry. 73(2):391-399.

 

Wong, K.H., Hynes, M.J., Todd, R.B., Davis, M.A. 2009. Deletion and overexpression of the Aspergillus nidulans GATA factor AreB reveals unexpected pleiotropy. Microbiology 155(12):3868-3880.

Wong, K.H., Todd, R.B., Oakley, B.R., Oakley, C.E., Hynes, M.J., and Davis, M.A. 2008. Sumoylation in Aspergillus nidulans: sumO inactivation, overexpression and live-cell imaging. Fungal Genetics and Biology 45:728-737

Wong, K.H., Hynes, M.J., Todd, R.B., and Davis, M.A. 2007. transcriptional control of nmrA by the bZIP transcription factor MeaB reveals a new level of nitrogen regulation in Aspergillus nidulans. Molecular Microbiology 66(2): 534-551

Bernardo, S.M.H., Gray, K.-A., Todd, R.B., Cheetham, B.F., and Katz, M.E. 2007. A regulatory role for non-catalytic hexokinases in Aspergillus nidulans. Molecular Genetics and Genomics 277 (5): 519-532.

Todd, R.B., Davis, M.A., and Hynes, M.J. 2007. Genetic manipulation in Aspergillus nidulans: heterokaryons and diploids for complementation, dominance and haploidization analyses. Nature Protocols 2 (4): 822-830.

Todd, R.B., Davis, M.A., and Hynes, M.J. 2007. Genetic manipulation in Aspergillus nidulans: meiotic progeny for genetic analysis and strain construction. Nature Protocols 2(4): 811-821

Todd, R.B., Hynes, M.J., and Andrianopoulos, A. 2006. The Aspergillus nidulans rcoA gene is required for veA-dependent sexual development. Genetics 174 (3): 1685-1688.

Todd, R.B., Fraser, J.A., Wong, K.H., Davis, M.A., and Hynes, M.J. 2005. Nuclear accumulation of the GATA factor AreA in response to complete nitrogen starvation by regulation of nuclear export. Eukaryotic Cell 4 (10):1646-1653.

Hynes, M.J. and Todd, R.B. 2003. Detection of unpaired DNA at meiosis results in RNA-mediated silencing. BioEssays 25(2): 99-103.

Todd, R.B., Greenhalgh, J.R., Hynes, M.J., and Andrianopoulos, A. 2003. TupA, the Penicillium marneffei Tup1p homologue, represses both yeast and spore development. Molecular Microbiology 48:85-94.

Small, A.J., Todd, R.B., Zanker, M.C., Delimitrou, S., Hynes, M.J., and Davis, M.A. 2001. Functional analysis of TamA, a coactivator of nitrogen regulated gene expression, in Aspergillus nidulans. Molecular Genetics and Genomics 265:636-646.

Todd, R.B., Lockington, R.A., and Kelly, J.M. 2000. The Aspergillus nidulans creC gene involved in carbon catabolite repression encodes a WD40 repeat protein. Molecular and General Genetics 263:561-570

Todd, R.B., Andrianopoulos, A., Davis, M.A., and Hynes, M.J. 1998. The Zn(II)2Cys6 binuclear cluster of FacB, the Aspergillus nidulans activator of acetate utilisation genes, binds dissimilar DNA sequences. The EMBO Journal 17 (7): 2042-2054.

Todd, R.B., and Andrianopoulos, A. 1997. Evolution of a Fungal Regulatory Gene Family: The Zn(II)2Cys6 Binuclear Cluster DNA Binding Motif. Fungal Genetics and Biology (Genomics Issue) 21(3): 388-405

Todd, R.B., Kelly, J.M., Davis, M.A., and Hynes, M.J. 1997. Molecular characterization of mutants of the acetate regulatory gene facB of Aspergillus nidulans. Fungal Genetics and Biology 22 (2): 92-102.

Todd, R.B., Murphy, R.L., Martin, H.M., Sharp, J.A., Davis, M.A., Katz, M.E., and Hynes, M.J. 1997. The acetate regulatory gene facB of Aspergillus nidulans encodes a Zn(II)2Cys6 transcriptional activator. Molecular and General Genetics. 254:495-504