Gene May Speed Plant Biotech ExperimentsBy
Experiments to give plants new, useful genes should be aided by a gene
called "cah." Agricultural
Research Service scientists have shown that "cah" can serve as a
safe, easy-to-use marker gene that lets plant biotechnologists know they've
successfully transferred a new, useful gene, such as a gene to bolster a plant's
resistance to disease or insect attacks. Today, plant biotechnologists have few
marker genes to choose from.
In tests with wheat plants, ARS scientist
Weeks of Lincoln, Neb., demonstrated the gene's suitability as a marker.
ARS is seeking a patent for this use of the gene.
Marker genes speed biotech experiments because they usually can be detected
earlier and easier than the useful gene with which they are paired. A marker
gene together with a gene that bolsters a plant's insect resistance, for
example, can be detected while plant cells are only a clump of tissue in a petri
dish. Other test tissue can be discarded, so scientists can focus on nurturing
the remainder into plantlets and, later, greenhouse plants ready for resistance
tests with insects.
In ARS experiments, clumps of tissue with the "cah" gene inside
survived when exposed to a chemical called cyanamide. Many clumps formed hardy
plantlets. Cells without the gene typically appeared brownish and do not
proliferate. Details are in the July issue of ARS' Agricultural Research
magazine, available on the World Wide Web at:
Scientific contact: J. Troy Weeks, USDA-ARS
and Forage Research Unit, 344 Keim Hall, University of Nebraska-Lincoln,
Lincoln, NE 68583, phone (402) 472-9640, fax (402) 472-4020, e-mail