Dr. Gladys Alexandre

Major Research Interests

Bacteria constantly monitor their environment and adapt to changing conditions by modulating the motility behavior and gene expression profiles. Bacteria respond to specific environmental signals that depend on the environment in which they find themselves in as well as their metabolic ability. My laboratory is interested in how motile bacteria use chemotaxis signal transduction pathways to detect and process environmental cues that trigger motility and other cellular responses. Research in the laboratory focuses on two microbial systems: Azospirillum brasilense and Rhizobium leguminosarum. Both microorganisms are plant-growth promoting alpha-proteobacteria. Azospirillum brasilense forms associations with the root system of various host plants (cereals and gramineous). Rhizobium leguminosarum bv. viciae forms nodules within the roots of its host, the pea. Both bacterial species employ multiple chemotaxis signal transduction pathways and associated receptors to detect chemical gradients and modulate their motility behavior. We are interested in comparing how motility and chemotaxis contribute to the adaptation of these bacteria to their environment and the establishment of the plant-microbe associations. We are using microbial physiology and molecular genetics approaches to address these questions and determine which signals are sensed and how they are processed during chemotaxis.

Research in the laboratory is currently supported by a NSF CAREER award.