Paul W. Paré

Associate Professor

Ph.D., The University of Texas, Austin, 1991

 

Postdoctoral Study, Institute of Biological Chemistry, Washington State University
 

Paré's Webpage

 

 

Phone: (806) 742-3062

Fax: (806) 742-1289

 

Biochemistry

Research activities in the laboratory of Professor Paré focus on understanding how plants produce natural products as well as how such chemicals function in the context of biological systems.  Experimental approaches range from organic synthesis to biochemistry and molecular biology. Plant systems that we have recently published on and routinely grow in the laboratory include Arabidopsis, corn, cotton, onion and tomato.  Caterpillars are reared in a laboratory incubator and several bacterial lines are maintained.  Specific research projects that are on going or have been completed during my time at Texas Tech University are described below.

Chemical Elicitors Induce Plant Defense Responses

Leaves normally release low levels of volatile chemicals, but when a plant is damaged by herbivorous insects, many more volatiles are released.  These volatiles attract both parasitic and predatory insects that are natural enemies of herbivores.  Activation of such defense responses by plants can be triggered by non-volatile elicitors that make direct contact with plant tissue or by volatile chemicals that are air-borne in their transmission.  An example of a non-volatile elicitor is volicitin (N-[17-hydroxylinolenoyl]-L glutamine) isolated from the regurgitant of the agricultural pest beet armyworm and activate in triggering the emissions of volatile organic compounds when in contact with damaged corn leaves.   Volatile components such as methyl jasmonate and certain C6 alcohols can also be released from and trigger defense responses in plants.  We are interested in characterizing the initial biochemical responses that are activated in model plant systems in response to chemical elicitors.

Bacterial Volatile Chemicals Trigger Plant Growth Promotion

Plant growth-promoting rhizobacteria are a wide range of root-colonizing bacteria with the capacity to enhance plant growth by increasing seed germination, plant weight, and crop yields.  Little has been reported as to the role of microbial volatiles in regulating plant growth and development, although we have recently observed that certain bacterial volatiles can serve as agents for triggering growth promotion in Arabidopsis.  We are interested in identifying genes that are up or down regulated by exposure to bacterial volatile emissions as a way to probe the signal transduction sequence responsible for enhanced plant growth with exposure to bacterial volatiles and chemical analogues.

Plant Carbon Allocation and Partitioning of Metabolites with Elevated CO2 Conditions

Space flight conditions can activate changes in the allocation of carbon in plants. Although many of these modifications to plant growth and development have been attributed to microgravitational forces, other space flight conditions, such as elevated carbon dioxide or volatile organic compounds imposed by growth in a closed system, may influence specific biochemical pathways, as well as the overall physiology of the plant. We are examining how elevated carbon dioxide levels and ethylene may influence carbon partitioning between volatile emissions, root secretions and the metabolic flux into constitutive secondary phytochemicals and primary metabolites.

Free-Radical Scavenging by Polyphenolic Flavonoid Compounds

Flavonoids are plant natural products that can reduce the abundance of oxidative free radicals in a biochemical system by scavenging and quenching radical species. Measurements of flavonoid reduction potentials and direct comparisons of flavonoids with other antioxidant compounds have been reported.  However, the specific mechanism of flavonoid antioxidation activity has not been elucidated. By identifying the major oxidative products formed by the reaction of model flavonoids with radical species, these radical generated products have provided insight into specific mechanisms of flavonoid-antioxidant reactions.

 
 Selected Publications

  • "Bacterial Volatiles Trigger Induced Systemic Resistance in Arabidopsis," Ryu, C.M.; Farag, M.A.; Hu, C.H.; Reddy, M.S.; Kloepper, J.W.; Paré, P.W.  Plant Physiology 2004, 134, 1017-1026.

  • "A Plasma Membrane Protein from Zea mays Binds with the Herbivore Elicitor Volicitin," Truitt, C.L.; Wei, H.X.; Paré, P.W.  Plant Cell 2004, 16, 523-532.

  • "Altered Leaf and Root Emissions from Onion (Allium cepa L.) Grown Under Elevated CO2 Conditions," Jasoni, R.; Kane, C.; Green, C.; Peffley, P.; Tissue, D.; Thompson, L.; Payton, P.; Paré, P.W.   Environmental and Experimental Botany 2004, 51, 273-280.

  • "Synthesis of Hydroxy-substituted Unsaturated Fatty Acids and the Amino-acid Insect-derivative Volicitin," Wei, H.X.; Truitt, C.L.; Paré, P.W.  Tetrahedron Letters 2003, 44, 831-833.

  • "C6-green Leaf Volatiles Trigger Local and Systemic VOC Emissions in Tomato.  Farag, M.A.; Paré, P.W.   Phytochemistry 2002, 61, 545-554.

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