Poster: Plant Pathogen/Symbiont Interactions

Abs # 758: Isolation and Characterization of Lipo-chitin oligosaccharides from three strains of Rhizobia with the ability to nodulate a restrictive mutant Phaseolus vulgaris (Common bean).

Presenter:	Bayshore, Sarah L., sb332892@ohiou.edu
Authors	Bayshore, Sarah L. (A)   Trese, Arthur T. (A)
Affiliations:	(A): Ohio University

Bacteria from the genus Rhizobium are microsymbionts on Phaseolus vulgaris (Common Bean). The bacteria enter the roots of the plant and begin fixing atmospheric nitrogen and converting it into a form that can be used by the plant. The plant provides the bacteria with protection and energy. The initiation and development of this relationship is mediated by chemical signals exchanged between the host plant and the bacteria. The host range of the bacteria is also determined by these chemical signals. My lab has isolated a mutant P. vulgaris that restricts nodulation. Bacterial strains were screened and I have found 3 strains out of 31 isolates that have the ability to nodulate the mutant. All 31 strains are from the same genus, so they all should produce the same nod factors that characterize them as P. vulgaris microsymbionts. I believe the three overcoming strains produce nod factors that have different modifications then the other bacteria in their same genus. Nod factors will be isolated using butanol extractions and high power liquid chromatography (HPLC). Characterization of the nod factors will be done using mass spectroscopy. The genes encoding the nod factors will be isolated using a cosmid library.