Dissertation Research: Do Virulence Costs Help Maintain Avr Genes in Plant Pathogen Populations?

University Of Chicago, Chicago IL

Investigators

Abstract

0107219 Bergelson Plants can recognize gene products produced by pathogens, and this recognition triggers a strong defensive response that severely limits the pathogen's growth in the plant. An important question in the area of plant disease, is "Why do pathogens carry genes which ultimately trigger a defense response against them"? In this Doctoral Dissertation Improvement Grant, the researchers propose to look for benefits associated with the pathogen genes that elicit plant defenses. They propose to take a plant pathogenic bacteria and remove several of the elicitor genes, and then compare the performance of the original strains (which have all the genes) to the mutant strain (which possesses a subset of the genes). The researchers will investigate several factors including disease pathology, epidemiology, and survival, under both greenhouse and natural field conditions. Agriculture and the plant biotechnology industry are very interested in pathogen defense elicitor genes. It is now possible to engineer plants to express new resistance genes that recognize the elicitor genes of common plant pathogens. Before such a strategy is attempted, it would be valuable to understand how the elicitor genes function and are maintained in pathogen populations. If elicitor genes can be removed with little or no fitness cost to the pathogens, then a biotechnology strategy that depends on the expression of elicitor genes can easily fail.