Date of this Version
Agricultural Research, January 2012
On one front, a team led by ARS plant physiologists Eric Schmelz and Alisa Huffaker has identified 10 compounds in corn, kauralexins and zealexins, which rapidly accumulate at fungal infection sites, impeding the microbes’ spread. Kauralexins and zealexins, members of a larger family of plant-defense compounds known as “terpenoid phytoalexins,” are also partly triggered by insect chewing—with Ostrinia nubilalis, the European corn borer, among species that find them distasteful.
On another front, Huffaker led the discovery of a new peptide (protein) in corn, ZmPep1, that’s produced in response to fungal infection. In addition to serving as a sort of “call to arms,” the peptide helps the plant mount a timely counter-offense.
“This is the first time a peptide signal has been shown to turn on biochemical defenses in maize,” notes Schmelz, who along with Huffaker published a paper on ZmPep1 in the March 2011 issue of Plant Physiology.
Huffaker, Schmelz, and seven coauthors from ARS and the University of Florida (UF) reported their kauralexin and zealexin findings in the March 2011 issue of Proceedings of the National Academy of Sciences and the August 2011 issue of Plant Physiology.