Iowa State researcher's paper in 'Nature' details genetic origins of corn on the cob

AMES, Iowa -- Before you bite into your next ear of fresh Iowa sweet corn, manual typewriter-style, stop and take a look at the plump, golden kernels and how they are aligned.

Iowa State University faculty member Erik Vollbrecht, along with lead researcher Robert Martienssen of Cold Spring Harbor Laboratory, have determined a genetic reason why modern corn's straight rows and compact ears evolved from corn's wild ancestor, teosinte.

The research findings are the topic of a paper in the July 24 advance online edition of the journal Nature. Vollbrecht, assistant professor of genetics, development and cell biology, is the lead author.

The paper details research conducted by Martienssen and Vollbrecht at Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, where Vollbrecht was a post-doctoral fellow before joining Iowa State.

The researchers isolated the ramosa1 corn gene and showed how it controls the arrangement and length of flower-bearing branches in corn, related cereal crops and ornamental grasses. The study indicates that during the domestication of corn, early farmers selected plants with special versions of the ramosa1 gene, likely forms that suppressed branching in the ear, leading to the straight rows and compact ears of modern corn.

The study reveals that plants with more ramosa1 activity (typical corn) tend to have fewer branches, shorter branches and fewer flowers. Plants with less ramosa1 activity (sorghum and rice, for example) tend to have more branches, longer branches, and more flowers.

To read Vollbrecht's paper, go to: www.nature.com.

Research funding was provided by the National Science Foundation, the United States Department of Agriculture, and the Life Sciences Research Foundation.