ITHACA, N.Y. -- Familiarity breeds contempt. Nonfamiliarity produces seed.

Just as humans have a natural aversion toward marrying kin, some food crop plants have genes that allow them to avoid being fertilized by "self-related" pollen. Now Cornell University's biologists have solved one more piece of the puzzle of how plants' self-incompatibility works on the molecular level.

The discovery, as reported in the today's journal Science , could enable genetic engineers to short-circuit the reproduction process and more easily hybridize improved varieties of plants.

Many commercial crops are genetic hybrids. Obtaining seed to plant commercial quantities of these crops, such as tomatoes, for example, requires the labor-intensive work of manual crossing. Without the process of manual crossing, the plants would not have the desired qualities of hybrids. But nature has come up with an efficient system for making hybrid seed, which, when understood at the molecular level, can have applications on a commercial scale. This process, termed self-incompatibility, "prevents inbreeding and promotes out-crossing and variability in plants," says June Nasrallah, Cornell professor of plant biology, and the lead author on the Science paper.

In addition to Nasrallah, co-authors of "Allele-Specific Receptor-Ligand Interactions in Brassica Self-Incompatibility" include Mikhail Nasrallah, Cornell professor of plant biology; Aardra Kachroo, Cornell postdoctoral researcher in plant biology; and Christel R. Schopfer, a former Cornell postdoctoral researcher who now conducts research in Germany.

Funding for the research was provided by a four-year grant from the National Institutes of Health for the purpose of understanding cellular communication systems. The Nasrallah group examined the reproductive processes of Brassica plants. Like humans and animal species, plants use eggs and sperm in order to make seed and mul
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Contact: Blaine P. Friedlander Jr.
bpf2@cornell.edu
607-255-3290
Cornell University News Service
6-Sep-2001