HR: 0830h
AN: A11F-0058    [PDF]
TI: Genetic Control of Methyl Halide Production in {\it Arabidopsis}
AU: * Rhew, R C
EM: rrhew@atmos.berkeley.edu
AF: Department of Geography, University of California, Berkeley, Berkeley, CA 94720-4740 United States
AU: * Rhew, R C
EM: rrhew@atmos.berkeley.edu
AF: Department of Earth System Science, University of California, Irvine, Irvine, CA 92697-3100 United States
AU: Ostergaard, L
EM: larsoe@biomail.ucsd.edu
AF: Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093-0116 United States
AU: Saltzman, E S
EM: esaltzma@uci.edu
AF: Department of Earth System Science, University of California, Irvine, Irvine, CA 92697-3100 United States
AU: Yanofsky, M F
EM: marty@biomail.ucsd.edu
AF: Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093-0116 United States
AB: Methyl chloride and methyl bromide are the primary carriers of natural chlorine and bromine to the stratosphere where they catalyze the destruction of ozone, whereas methyl iodide influences aerosol formation and ozone loss in the troposphere. Methyl bromide is also an agricultural fumigant whose use is scheduled to be phased out by international agreement. Despite the economic and environmental importance of these methyl halides, their natural sources and biological production mechanisms are poorly understood. Currently identified sources include oceans, biomass burning, industrial and agricultural use, fuel combustion, salt marshes, wetlands, rice paddies, certain terrestrial plants and fungi, and abiotic processes. We demonstrate that the model plant {\it Arabidopsis thaliana} produces and emits methyl halides and that the enzyme primarily responsible for the production is encoded by the {\it HARMLESS TO OZONE LAYER} ({\it HOL}) gene located on chromosome II. In mutant plants that have a disruption of the {\it HOL} gene, methyl halide production is largely eliminated. A phylogenetic analysis using the {\it HOL} gene suggests that the ability to produce methyl halides is widespread among vascular plants. This approach provides a genetic basis for understanding and predicting patterns of methyl halide production by plants.
DE: 0315 Biosphere/atmosphere interactions
DE: 0322 Constituent sources and sinks
DE: 1615 Biogeochemical processes (4805)
DE: 1851 Plant ecology
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting