Ph.D., Massachusetts Institute of Technology, 1989
Postdoctoral Research: University of California — Berkeley
Lab website: http://www.plantpath.wisc.edu/users/afbent
Address: 886 Russell Labs
Department: Plant Pathology
Disease resistance and defense signal transduction in plants
Please see http://www.plantpath.wisc.edu/users/afbent for the most current lab description, links and pdf document library.
Our work examines plant disease resistance and the molecular basis of plant resistance to infection by microbial pathogens. The plant immune system includes some components that are conserved with animals, and a number of capacities that are unique to plants. We study disease resistance in part because host-pathogen dynamics and the molecular workings of immune systems are fascinating biological topics. We also study this because on a practical level, one of the best ways to control plant diseases is through use of genetically determined resistance. This approach is convenient for the grower and minimizes the need for costly, time-consuming and/or potentially toxic external treatments. Plant breeders have utilized disease resistance genes in cultivar development for literally thousands of years, but the molecular basis of this resistance is only partly understood. Identification and study of the plant genes and the biochemical/cellular processes that control disease resistance can bring us closer to understanding the basic mechanisms of pathogen recognition, defense signal transduction and activation of resistance responses. These discoveries also foster the development of specific approaches for improvement of disease resistance.
Much of the work in our laboratory examines Arabidopsis thaliana because of the extraordinary experimental versatility of this plant species. We also study soybean, Brassica and other plant species. We work with many different pathogens, but most typically study Pseudomonas syringae pv. tomato and Xanthomonas campestris pv. campestris.
We are presently focused on three projects:
1) Leucine-rich repeat (LRR) structure/function, and plant detection of bacterial flagellin.
We are developing ways to identify and manipulate LRR active sites within plant disease resistance proteins and other LRR proteins. The flagellin receptor FLS2 of Arabidopsis is our primary model. We are working to understand how ligand specificity is determined, and how it can be altered in a targeted way by in vitro evolution. We are also examining the ways in which some bacterial pathogens have evolved to escape plant detection of their flagellins.
2) Study and manipulation of disease resistance in soybean.
Agrobacterium rhizogenes-mediated root transformation and other methods are being used to facilitate molecular genetic dissection of soybean disease resistance. This includes a new, collaborative effort to nail down the nature of the rhg1 and Rhg4 genes that confer significant resistance to soybean cyst nematode.
3) Previously unidentified biochemical responses of plants to pathogen infection
Using microarray expression profiling data as a starting point, and Arabidopsis gene knockout plant lines for initial tests, we have identified relatively unexamined aspects of the plant response to pathogens. We are now conducting further study of the identified pathways, for example, the role of poly(ADP-ribosyl)ation in plant responses to infection.
Cook*, D.E., Lee*, T.G., Guo*, X., Melito, S., Wang, K., Bayless,
A., Wang, J., Hughes, T.J., Willis, D.K., Clemente, T., Diers, B.W.,
Hudson, M.E. and Bent, A.F. (*co-first authors), 2012. Copy number
variation of multiple genes at Rhg1 mediates nematode resistance in
soybean. Science 338:1206-1209.
Sun*, W., Y. Cao*, K.L. Jansen, P. Bittel, T. Boller and A.F. Bent (*co-first authors), 2012. Probing the Arabidopsis flagellin receptor: FLS2-FLS2 association and the contributions of specific domains to signaling function. Plant Cell 24: 1096–1113.
Helft, L., V. Reddy, X. Chen, T. Koller, L. Federici, J. Fernandez-Recio, R. Gupta and A. Bent, 2011. LRR Conservation Mapping to predict functional sites within protein leucine-rich repeat domains. PLoS ONE 6(7): e21614. doi:10.1371/journal.pone.0021614
Briggs, A.G. and A.F. Bent, 2011. Poly(ADP-ribosyl)ation in plants. Trends Plant Sci. 16:372-372-380.
Sun, W., L. Liu and A.F. Bent, 2011. Type III secretion–dependent host defense elicitation and Type III secretion–independent growth within leaves by Xanthomonas campestris pv. campestris. Mol. Plant Pathol. 12:731-745.
Adams-Phillips, L., A.G. Briggs and A.F. Bent, 2010. Disruption of poly(ADP-ribosyl)ation mechanisms alters responses of Arabidopsis thaliana to biotic stress. Plant Physiol. 152:267-280.
Allen, C., A. Bent and A. Charkowski, 2009. Underexplored niches in research on plant pathogenic bacteria. Plant Physiol. 150:1631-1637.