A team of scientists led by University of Missouri maize geneticist Paula McSteen has identified a gene essential for forming the ears in corn. The new research, which appears in the journal Molecular Plant, extends the growing biological understanding of how different parts of corn plants develop, which is important information for a crop that is a mainstay of the global food supply.
"Corn is a vitally important crop, and the ears are the most crucial organ for plant yield. Knowing the genes that control this process and how they function together at a molecular level is crucial for efforts to increase crop yield," said McSteen, who is an associate professor of biological sciences in the College of Arts and Science and a principal investigator in Christopher S. Bond Life Sciences Center. "The information we glean from corn is also likely to be applicable to other cereals, including rice and wheat, because they also form grains on branches."
The researchers found that a gene called barren stalk2, or ba2, affects development of axillary meristems, which are special cells that give rise to the ears. As a corn plant grows, these cells are formed at nodes along the stalk. These nodes look like tiny grooves, or indentations, in the stem. When the plant is ready to make ears, these cells begin to divide and bud out from the stalk. These buds elongate to form the ear shoots and ultimately become the harvestable ears. The process is initiated by delivery of a hormone, called auxin, to the nodes that signals the cells to make ears.
A normal corn plant (left) and a barren stalk2 (ba2) plant (right). Plants with a mutation in the ba2 gene cannot grow ears, hence the name barren stalk. Photo Credit: University of Missouri
(Source: Crop Biotech Update, International Service for Acquisition of Agri-Biotech Applications. www.isaaa.org)
