Submitted to: Canadian Journal of Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 12, 2006
Publication Date: March 1, 2007
Citation: Chen, J., Groves, R.L., Civerolo, E.L. 2007. Surface Motility of Xylella Fastidiosa Visualized by Oblique Illumination. Canadian Journal of Microbiology 53:435-439. Interpretive Summary: Xylella fastidiosa causes many economically important plant diseases, such as Pierce’s disease of grapevine and almond leaf scorch disease. X. fastidiosa is very difficult to culture in artificial media. For this reason, many culture-based biological traits of the bacterium remain unknown. Among them is the bacterial surface translocation. We studied two almond leaf scorch strains representing both A- and G-genotypes of X. fastidiosa and found evidence indicating that X. fastidiosa is very capable of moving on a culture medium surface. A diffused matrix ring was also observed around colonies a G-genotype strain. New information about bacterial movement in vitro will provide clues about movement in planta which may be directly related to pathogenicity.
Technical Abstract: Xylella fastidiosa is an important plant pathogen. Because of the nutritional fastidiousness, culture-based characterization of this bacterium has been difficult. Using two almond leaf scorch strains, M12 (A-genotype) and M23 (G-genotypes) as models, we found that X. fastidiosa cells were capable of surface translocation as evidenced by the presence of two types of movement trails on PW and PD3 plates solidified by GelRite. The curved type trails suggest the gliding movement and the straight type trails suggest possible darting movement. Colony morphology is the function of the rate of surface translocation and the rate of slime production. In addition, a diffused matrix ring of unknown function was detected around colonies of strain M23.