Structure of the sensory domain of McpX from , the first known bacterial chemotactic sensor for quaternary ammonium compounds.

The α-proteobacterium can live freely in the soil or engage in a symbiosis with its legume host. facilitates nitrogen fixation in root nodules, thus providing pivotal, utilizable nitrogen to the host. The organism has eight chemoreceptors, namely McpT to McpZ and IcpA that facilitate chemotaxis.

Quantification of Bacterial Chemotaxis Responses at the Mouths of Hydrogel Capillaries.

Many chemotaxis assays allow for the assessment of bacterial chemotaxis by determining the number of cells migrating toward a chemoattractant or away from a chemorepellent. Some of these assays use a capillary filled with a chemoeffector/agarose mixture to allow cells to accumulate at the mouth of the capillary. Subsequently, assumptions about the relative strengths of chemotaxis strength are based on visual comparisons.

Sinorhizobium meliloti Chemotaxis to Multiple Amino Acids Is Mediated by the Chemoreceptor McpU.

The legume symbiont Sinorhizobium meliloti is chemoattracted to compounds exuded by germinating seeds of its host alfalfa. This response is mainly mediated by the S. meliloti chemoreceptor McpU.

Sinorhizobium meliloti chemotaxis to quaternary ammonium compounds is mediated by the chemoreceptor McpX.

The bacterium Sinorhizobium meliloti is attracted to seed exudates of its host plant alfalfa (Medicago sativa). Since quaternary ammonium compounds (QACs) are exuded by germinating seeds, we assayed chemotaxis of S. meliloti towards betonicine, choline, glycine betaine, stachydrine and trigonelline.

Contribution of Individual Chemoreceptors to Sinorhizobium meliloti Chemotaxis Towards Amino Acids of Host and Nonhost Seed Exudates.

Plant seeds and roots exude a spectrum of molecules into the soil that attract bacteria to the spermosphere and rhizosphere, respectively. The alfalfa symbiont Sinorhizobium meliloti utilizes eight chemoreceptors (McpT to McpZ and IcpA) to mediate chemotaxis. Using a modified hydrogel capillary chemotaxis assay that allows data quantification and larger throughput screening, we defined the role of S.

Sinorhizobium meliloti chemoreceptor McpU mediates chemotaxis toward host plant exudates through direct proline sensing.

Bacterial chemotaxis is an important attribute that aids in establishing symbiosis between rhizobia and their legume hosts. Plant roots and seeds exude a spectrum of molecules into the soil to attract their bacterial symbionts. The alfalfa symbiont Sinorhizobium meliloti possesses eight chemoreceptors to sense its environment and mediate chemotaxis toward its host.