Submitted to: Annual International Plant & Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: 12/23/2005
Publication Date: 1/5/2006
Citation: Nagendran, S., McGrath, J.M. 2006. Host-pathogen interaction of sugarbeet seedlings with rhizoctonia solani. Annual International Plant & Animal Genome Conference. Abstracto No. W182.
Technical Abstract: The progress curve of seedling damping-off caused by Rhizoctonia solani showed three distinct stages - an initial rapid disease progress stage, an intermediate stationary phase, and a final decline and death phase, in the compatible interaction. Both virulent and avirulent fungal isolates initiated the infection process in susceptible and resistant cultivars but avirulent isolates and resistant cultivars recovered from infection. Resistant and susceptible interactions were examined by light, fluorescence, confocal and scanning electron microscopy. All fungal isolates penetrated the epidermis and established themselves in the cortex of both resistant and susceptible seedlings. A difference was evident at the endodermis between compatible and incompatible interactions, with the incompatible reaction showing limited penetration, and less colonization of the stele accompanied by increased autofluorescence. cDNA-AFLP showed a large magnitude change in gene expression profiles between compatible and incompatible interactions, and little similarity was seen between incompatible interactions (e.g. resistant – virulent or susceptible – avirulent). Expression patterns of selected genes could aid in unraveling the mechanisms of pathogenicity of R. solani and the defense responses of sugar beet.