Farmers use chemical growth regulators to thin their fruit trees, speed up ripening, and then delay the fruits' falling. Of course, plants have their own ways of doing this--with growth hormones. If scientists could figure out how to switch Mother Nature's hormones on and off, environmentally damaging chemicals could take a backseat.
Michigan State University scientists have isolated from corn the first gene controlling the action of a plant growth hormone. The gene regulates the binding of indole-3-acetic acid, or IAA, to a sugar molecule. This binding prevents the IAA hormone from promoting growth. Isolating and altering equivalent genes from other crops could produce plants whose fruit follows a tailored growth pattern when triggered by, say, a specific temperature. MSU biochemist Robert S. Bandurski estimates that such genetic methods could be available in two years. "As we move toward a greener world, we'd like to control growth genetically rather than chemically," he says.