CHEMOTAXIS OF PANTOEA SP. YR343 IN A SYNTHETIC POPULUS DELTOIDES RHIZOSPHERE

The colonization of plant roots by bacteria found in rhizosphere can help plants adapt to stresses. Colonization is facilitated by a rhizobacteria’s ability to recognize and move towards a plant root, frequently using chemotaxis. This study examines the chemotactic response of the rhizobacteria Pantoea sp. YR343 towards metabolites known to be produced by the roots of poplar trees: glucose, sucrose, salicin, myoinositol, citric acid, succinic acid, malic acid, glycerol, and amino acids (serine). Identifying which compounds Pantoea sp. YR343 is chemotactic towards is important to understanding the establishment of the plant-microbe interface. Chemotaxis was characterized by methods such as soft motility assays, capillary assays, 2D videos, and Digital Holographic Microscopy. The chemotactic activity of a transposon mutant of the methyl-accepting chemotaxis protein (MCP) PMI39_02190 was also compared to the wildtype strain. From these experiments, it was found that the wildtype strain is chemotactic towards malic acid and myoinositol while PMI39_02190 may be chemotactic towards malic acid. These results continue to inform how the bacteria recognize and establish a relationship with plants, using Pantoea sp. YR343 and Populus deltoides as models.