Elucidation of the Signaling Pathway in Plant Defenses

EPA Grant Number: U914960
Title: Elucidation of the Signaling Pathway in Plant Defenses
Investigators: Rate, Debra N.
Institution: University of Colorado at Boulder
EPA Project Officer: Lee, Sonja
Project Period: January 1, 1996 through January 15, 2001
Project Amount: $102,000
RFA: STAR Graduate Fellowships (1996) RFA Text |  Recipients Lists
Research Category: Fellowship - Molecular Biology/Genetics , Academic Fellowships , Biology/Life Sciences


The objective of this research project is to understand the mechanisms of signaling cascade through the investigation and characterization of the expression of defense-associated genes using the genetically tractable plant, Arabidopsis thaliana. Plants are subject to disease and abiotic stresses, and have developed strategies to defend themselves against these environmental attacks. The signaling pathway that leads to the plant defense responses as a result of these stresses proceeds through undefined territory. Some of the known initiators of the pathway leading to defense responses include pathogen infection, oxidative stress, and UV-light exposure. Knowledge of the role and regulation of these defenses could lead to the design of disease and/or stress tolerant plants and to a reduction of pesticide use. Whether it is one pathway with multiple intersecting branch points or separate pathways needs to be delineated. Two genes induced through different branches of this pathway in response to pathogen attack are the GST1 and LOX1 genes of Arabidopsis.


My strategy is to use gene fusions of the GST1 and LOX1 promoters and reporter genes to facilitate the isolation of mutants altered in their regulation of these genes. I have available transgenic plants harboring GST1 promoter-reporter gene constructs, and I will construct LOX1 promoter and reporter gene fusions to transform Arabidopsis plants. Once I establish that the expression of GST1 and LOX1 gene fusions reflects the known patterns of gene expression, I will mutate the transgenic seed to disrupt the signaling pathway and screen the transgenic plants for aberrant gene expression. I will characterize these mutants for the source of the pathway defect. Additional steps in the defense-response pathway will be identified in this manner. From elucidation of the defense-response pathway may come the rational design of disease and stress-resistant agriculturally important plants, which would lead to a reduction in chemical use and bring pesticide use to a sustainable level.

Supplemental Keywords:

fellowship, signaling pathway, abiotic stresses, disease, plant defenses, pesticides, Arabidopsis thaliana, gene fusions, transgenic plants, gene expression, defense-response pathway, RFA, Scientific Discipline, Ecosystem Protection/Environmental Exposure & Risk, Ecology, exploratory research environmental biology, Ecosystem Protection, Environmental Chemistry, Environmental Microbiology, Biochemistry, Ecological Risk Assessment, Ecology and Ecosystems, Molecular Biology/Genetics, Biology, disease resistant plant, transduction, pathogens, pathogen recognition, signal transduction, transgenic plants, plants, disease resistance, N gene

Progress and Final Reports:

  • 1996
  • 1997
  • 1998
  • 1999
  • 2000
  • Final