Biologists at the University of California, San Diego have identified genes in a laboratory weed that are necessary for normal seed dispersal.
In the April 14th issue of Nature, the researchers report the identification of two genes in Arabidopsis that, when inactivated, prevent this weed from shattering its seed-containing pods. This is significant because the inactivation of these same genes in canola and other closely related, commercially important crops should prevent the premature dispersal of seeds that typically results in significant losses of yield.
The discovery could dramatically increase the harvesting of canola seeds, a $9-billion-a-year industry worldwide that is rapidly growing because of the health benefits of canola oil, but is now hampered because so much of that crop is lost to pod shatter. It could also lead to commercially significant savings in the collection of seeds for valuable hybrids of broccoli, cauliflower and other crops.
"Under adverse conditions, such as very windy conditions, which is not all that uncommon during the harvesting time, as much as half of the canola crop ends up on the ground," says Martin F. Yanofsky, a professor of biology at UCSD who headed the research team that made the discovery. "If you can double the yield, that means you can plant the canola on half as much land and use half as much of the chemical fertilizers and pesticides that are now routinely sprayed on these plants."
In their study, UCSD biologists Sarah J. Liljegren, Gary S. Ditta, and Yanofsky identified a type of gene, called a "shatterproof" gene, that allows Arabidopsis plants to disperse their seeds. Two other scientists from the University of California, Davis, John L. Bowman and Yuval Eshed, and a former UCSD scientist, Beth Savidge, contributed to the study. The UCSD scientists determined that mutant strains without two normal copies of this type of gene, lacked the ability to disperse seeds through pod shatter.