In a paper that appears in the December 2 issue of the journal Nature, the scientists report their discovery of a gene that regulates the development of secondary branching in plants, presumably permitting the highly branched, bushy teosinte plant to be transformed into the stalk-like modern maize.
The researchers say the presence of numerous variants of this gene in teosinte, but only one variant of the gene in all inbred varieties of modern maize, provides tantalizing evidence that Mesoamerican crop breeders most likely used this trait in combination with a small number of other traits to selectively transform teosinte to maize, one of the landmark events in the development of modern agriculture.
"What we know is that this gene is critical for branching to take place in maize, including the branches that give rise to the ears of corn," says Robert J. Schmidt, a professor of biology at UCSD who headed the research team. "And we presume that there was something unusual in the morphology that these early farmers selected from the wild teosinte that made it easier for them to plant, grow or harvest their crops. This gene will give us some important new clues to what genetic traits these plant breeders focused on when they transformed teosinte to maize. In a broader context, it is quite possible that the same gene in other plant species is equally essential to the overall architecture that a particular plant assumes by programming the very cells that produce new branches."
The gene cloned by the scientists is called barren stalk1 because when the gene product is absent a relatively barren s
Contact: Robert J. Schmidt
University of California - San Diego