The effect of pathogens on plant genome stability

Resistance (R) genes, a key factor in determining the resistance of plants, have been shown often to be highly allelic entities existing in duplicated regions of the genome. This characteristic suggests that R-gene acquisition may have arisen through frequent genetic rearrangements as a result of transient, reduced genome stability. Tabacco plants transgenic for a recombination construct exhibited reduced genome stability upon infection with a virulent pathogen (tobacco mosaic virus). The reduced genome stability manifested as an increase in recombination events in the transgene. Such increases were observed following a virulent pathogen attack. This increase in recombination was shown to be systemic and was observed prior to systemic viral movement suggesting the presence of a systemic recombination signal. Further molecular analyses revealed that specific R-gene loci experience a large frequency of rearrangements following a virulent pathogen encounter. The possible targeting of instability to R-gene regions may be controlled through epigenetic processes, in particular, DNA methylation.

Authors

• Filkowski, Jody
• University of Lethbridge. Faculty of Arts and Science

• Dissertations, Academic
• Plants -- Disease and pest resistance -- Genetic aspects
• Plant diseases -- Genetic aspects
• Plant molecular genetics

Identifier

hdl:10133/254

OAI identifier oai:identifier

oai:opus.uleth.ca:10133/254