Impact of UV-B on Maize

EPA Grant Number: R824900
Title: Impact of UV-B on Maize
Investigators: Walbot, Virginia
Institution: Stanford University
EPA Project Officer: Hahn, Intaek
Project Period: December 1, 1996 through November 30, 1999
Project Amount: $450,000
RFA: Exploratory Research - Environmental Biology (1996) RFA Text |  Recipients Lists
Research Category: Biology/Life Sciences , Ecosystems


The purpose of this project is to determine the capacity of UV-B wavelenghts present in natural sunlight to cause mutations in maize pollen DNA. Plant pollen carries the haploid sperm genomes that transmit to the next generation. Mutation will be assessed by several tests. First, production of visible mutants will be measured after crossing to a tester line and selfing the progeny; this test determines the biological outcome of UV-B induced DNA damage and repair processes. Second, the levels of specific lesions in DNA including pyrimidine dimers and 6,4-photoproducts will be quantified using monoclonal antibodies and polymerase chain reaction protocols for assessing damage in the genome as a whole and in individual genes, respectively. Third, activation of Mutator transposable elements will be monitored by restoration of a spotted kernel phenotype and enhanced generation of new mutants in progeny receiving a newly activated transposon; this test measures the biological amplification of damage initiated by UV-B. Mutator transposons are powerful, endogenous mutagens that are maintained in a cryptic form in the genome, and they are activated by DNA damage. Collectively these experiments will demonstrate the level of physical damage, the resulting mutational load caused directly by UV-B and lesion repair, and the mutational load resulting after activation of a biological amplifier. UV-B sources modeling current fluence in sunlight in the temperate zone and with 65% ozone depletion will be used to further our understanding of the impact of ozone depletion on mutation in higher plants.

Publications and Presentations:

Publications have been submitted on this project: View all 5 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 3 journal articles for this project

Supplemental Keywords:

air, photobiology, genetics, RFA, Scientific Discipline, Air, Ecosystem Protection/Environmental Exposure & Risk, Ecology, air toxics, Environmental Chemistry, Ecosystem/Assessment/Indicators, Ecosystem Protection, exploratory research environmental biology, Chemical Mixtures - Environmental Exposure & Risk, Chemistry, Ecological Effects - Environmental Exposure & Risk, Ecological Effects - Human Health, Biology, Ecological Indicators, ecological effects, ecological risk assessment, photobiology, stratospheric ozone, antibody assay, UV effects, ozone depletion, environmental stressor, gene-environment interaction, environmental mutagens, ecological assessment, UVB, plant pollen, genetic differentiation, maize, UV-B radiation

Progress and Final Reports:

  • 1997
  • 1998
  • Final Report