Gretchen Kuldau Ph.D.

Areas of Interest

Role of mycotoxins in fungal biology, genetics and molecular biology, prevention of mycotoxin accumulation in feeds and forages; genetics and biology of endophytic fungi

Program Interests

Research in my lab focuses on mycotoxigenic fungi and their interactions with plants. Mycotoxins are fungal secondary metabolites that are toxic to humans and animals. These naturally occurring toxins are of concern for both human and animal health since some are human carcinogens and others can cause fatal diseases in farm animals. In most cases, the biological motivation for mycotoxin production is unknown. While we have a relatively clear understanding of the nature of many of the commonly found mycotoxins we often do not know why they are made. One of the primary goals of my program is to understand why fungi produce mycotoxins. Such knowledge should provide the basis for new strategies for prevention of accumulation of mycotoxins in food and feed.

Fusarium verticilloides is an important mycotoxigenic fungus and is found wherever maize, its primary host, is cultivated. F. verticilloides, like most Fusarium species, produces the mycotoxin fusaric acid. We are exploring the role of fusaric acid in plant-fungus interactions using molecular genetic approaches. This mycotoxin has been implicated as a plant toxin so we are examining the role of fusaric acid in fungal virulence. We are also looking at the role of fusaric acid in asymptomatic infections of maize.

A number of mycotoxigenic fungi exist as endophytes during some or all of their lives. Endophytes are microorganisms that live internal to plant tissues but cause no observable symptoms on their plant host. Some endophytic fungi can be pathogenic under certain environmental and or developmental conditions. Very little is known for any fungus about the genetic basis for asymptomatic colonization of plants or about why symptomless infections sometimes become symptomatic. We are working to identify genes specifically expressed during endophytic colonization of maize by F. verticilloides. Our approach to this problem employs the tools of fungal molecular genetics.

For information on moldy grains, mycotoxins and feeding problems, see the following Web site:
http://www.oardc.ohio-state.edu/ohiofieldcropdisease/Mycotoxins/mycopagedefault.htm.

Publications:

Kuldau, G. A., and M. A. Mansfield. 2006. Mycotoxins and mycotoxigenic fungi in silages.  Silage for Dairy Farms Conference, pp. 91-99, January 23-25, 2006, Camp Hill, PA, Natural Resource, Agriculture and Engineering Service, Ithaca, NY.

Mansfield, M. A., De Wolf, E. D., and Kuldau, G. A. 2005. Effect of weather conditions, cultural practices, and feed quality on deoxynivalenol content in maize silage.  Plant Disease, 89:1151-1157.

Nita, M., Tilley, K., DeWolf, E., and Kuldau, G. 2005. Effects of moisture during and after anthesis on the development of Fusarium Head Blight of wheat and mycotoxin production. In: Canty, S. M., Lewis, J., Siler, L., and Ward, R. W. (Eds.), Proceedings of the National Fusarium Head Blight Forum; 2005 Dec. 11-13, Milwaukee, MN. East Lansing: Michigan State University. pp. 125-128. 

Bacon, C. W., Hinton, D. M., Porter, J. K., Glenn, A. E. and Kuldau G. A. 2004. Fusaric acid, Fusarium verticillioides metabolite, antagonistic to the endophyte biocontrol bacterium Bacillus mojavensis. Canadian Journal of Botany 82:878-885.

Dillehay, B. J., Roth, G. W., Calvin, D. D., Kratochvil, R. J., Kuldau, G. A., and Hyde, J. A. 2004. Performance of Bt-corn hybrids, their near isolines and leading corn hybrids in Pennsylvania and Maryland. Agronomy Journal 96:818-824.

Geiser, D. M., del Mar Jimenez-Gasco, M., Kang, S., Makalowska, I., Veeraraghaven, N., Ward, T. J., Zhang, N., Kuldau, G. A., and O'Donnell, K. 2004. FUSARIUM-ID v.1.0: A DNA sequence database for identifying Fusarium. European Journal of Plant Pathology 110:473-479.

Kang, S., J. E. Ayers, E. D. De Wolf, D. M. Geiser, G. A. Kuldau, G. W. Moorman, E. Mullins, W. Uddin, J. C. Correll, G. Deckert, Y.-H. Lee, Y.-W. Lee, F. N. Martin, and K. Subbarao. 2002. The internet-based fungal pathogen database: a proposed model. Phytopathology 92:232-236.

Tooley, P. W., E. Goley, M. M. Carras, R. D. Frederick, E. Webber, and G. Kuldau. 2000. Characterization of Claviceps sp. pathogenic on sorghum based on sequence analysis of B-tubulin and EF-1a regions." Submitted to Mycologia.

Kuldau, G. A., and I. E. Yates. 2000. "Evidence for Fusarium endophytes in cultivated and wild plants." In: Biology and evolution of microbial endophytes. C. W. Bacon and J. F. White Jr., eds. pp. 85-117.

Kuldau, G. A., and C. W. Bacon. 2000. "Biology and toxicity of Clavicipitaceae ." In: Foodborne disease Handbook, vol. 3. Y. H. Hui, R. A. Smith, and D. G. Spoerke eds. Marcel Dekker, Inc., New York, pp. 503-534.

Kuldau, G. A., H.-F. Tsai, C. L. Schardl. 1999. "Genome sizes of Epichloe species and anamorphic hybrids." Mycologia 91: 776-782.