Examination of the role of lipopolysaccharide in antibiotic stress tolerance and nodulation of Paraburkholderia tuberum

Within the outer structures of Gram-negative bacteria, lipopolysaccharide (LPS) is known to maintain structural integrity and is required for the induction of root nodules in some plant species. However, the role of LPS in the rhizobia Paraburkholderia tuberum has not been fully explored in scholarship, thereby this research focuses on the role of LPS in the response of P. tuberum to various antibiotics and during nodulation. To determine the importance of LPS in P. tuberum, a mutant in lptE, which is defective in LPS transport, was tested for its response to various antibiotic stressors and its ability to nodulate Phaseolus vulgaris (black bean). It was found that mutants defective in lptE showed increased sensitivity to antibiotics, demonstrating the protective role LPS has for P. tuberum. In addition, bean formed ineffective nodules in response to the lptE mutant. Overall, my findings show how crucial LPS is for protecting plant associative bacteria from environmental stressors and interacting with host plants, allowing this to possibly be applicable in agriculture and restoration work.