The surprising finding in studying the mutant was that a single gene could affect so many diverse traits, Jenks said. Another somewhat similar mutant Arabidopsis showed alterations only in wax and seed development, but not in the other mutated RST1 traits. This was a major clue that changes in lipid synthesis were somehow altering seed development.
Scientists already know that lipids play an important role in signaling developmental changes in plants and animals, and that other plants and animals, including humans, have genes similar to RST1. Jenks and his team now want to determine the exact role of RST1 in lipid signaling that affects plant development, particularly its role in crop seed self-thinning mechanisms through embryo abortion.
Unlike some other mutants that abort all of its seeds, the mutant RST1 plant aborts only about 70 percent of the seeds, he said.
"RST1 is not required for seed development, but it does influence how seeds develop, perhaps playing a role in regulating the number of seeds a plant will support to maturity," Jenks said. "Seed abortion by plants likely is a tightly regulated process that necessitates allowing some seed loss to conserve resources in a stressful environment without aborting all seeds, which would leave the plant with no healthy offspring."
If researchers learn how to control plant embryo abortion, they may be able to increase yield by helping plants shed fewer seeds, grains or fruits, especially under drought conditions and in other stressful environments.