Identifying genes in Burkholderia unamae that play a role in plant tissue colonization by transposon mutagenesis
Authors:Chris Henderson, Ann Tabutsadze
Mentor:Shelley Thai Ph.D., Assistant Professor of Biology, Glendale Community College
The genus Burkholderia has been investigated for its involvement in pathogenesis. Burkholderia unama is a non-pathogenic species that has been isolated and shown to confer plant-growth promoting properties. How the endosymbionts colonize the plant tissue is yet to be determined. This study aims to investigate the genes involved in motility and exopolysaccharide (EPS) production, properties typically associated with the ability of bacteria to colonize plant tissue. To identify genes responsible for these phenotypes, random mutations were introduced into B. unamae using the transposon Tn5-RL27. Phenotypes of interest were screened and molecular methods were performed to identify the disrupted gene. Thirteen mutations in different genes were studied that affected one or both of these phenotypes. The affected genes were widely varied. One mutation that resulted in both overproduction of EPS and the loss of motility was in a hypothetical protein, which was shown to be orthologous to membrane carboxypeptidases and part of the glycosyl transferase family. Another mutation showed reduced EPS production and affected the bacterium’s ability to divide properly. This disrupted gene was identified as mraZ, known for playing a role in cell wall biosynthesis and cell division in E. coli.