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Gladys Alexandre

Associate Head, Professor



Research in the laboratory aims at gaining a greater understanding of the strategies used by diverse bacteria to sense and respond to changes in the environments. Using bacteria chemotaxis signal transduction in soil bacteria as a model system, research conducted in the laboratory seeks to elucidate how sensory information is processed by chemotaxis-like signal transduction pathways, how multiple cellular responses may be controlled by a single pathway as well as how the activity ofparallel chemotaxis signal transduction pathways is coordinated to generate an integrated adaptive response. The laboratory uses microbial genetics, biochemistry as well as a suite of "omics" approaches to address such questions.

Description of Research

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 the 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.


  • PhD: Microbial Ecology - Claude Bernard University, France (1998)
  • MS: Microbiology - Claude Bernard University (1995)
  • MS: Plant Physiology - Claude Bernard University (1994)
  • BS: Biology - Claude Bernard University(1992)



Contact Information

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