Gene May Speed Plant Biotech Experiments

By Marcia Wood
July 30, 1998

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 J. Troy 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:

/is/AR/archive/jul98/gene0798.htm

Scientific contact: J. Troy Weeks, USDA-ARS Wheat, Sorghum and Forage Research Unit, 344 Keim Hall, University of Nebraska-Lincoln, Lincoln, NE 68583, phone (402) 472-9640, fax (402) 472-4020, e-mail tweeks@unlinfo.unl.edu.