Detailed study of corn plant response to green leafy volatiles (GLVs)
Monday, November 16, 2015
Exhibit Hall BC (Convention Center)
Arash Maleki
,
Center for Chemical Ecology, Department of Entomology, Pennsylvania State University, University Park, PA
Irmgard Seidl-Adams
,
Entomology, Pennsylvania State University, State College, PA
Gary Felton
,
Entomology & Center for Chemical Ecology, Pennsylvania State University, University Park, PA
James H. Tumlinson
,
Entomology, Pennsylvania State University, University Park, PA
Corn plants attacked by herbivores release the GLVs (E)-2-hexenal, (Z)-3-hexenal, (Z)-3-hexen-1-ol and Z-3-hexenyl acetate. Several ecological roles of GLVs have been put forward, in particular that of an intra or inter plant priming signals. In plants receiving the volatile signal a cascade of events is induced, resulting in an augmented defense response upon subsequent damage. In this process a burst of Jasmonic acid (JA), a plant hormone involved in wounding and herbivory responses, is one of the first steps, followed by the up-regulation of terpene synthesis genes.
In order to investigate the mechanism of plant response to GLVs, we need to know which of the GLVs are actually active inside the plant. While there is evidence about high toxicity of aldehyde GLVs for plant cells, it seems that aldehyde metabolites are transient and are converted into alcohol and acetate derivatives by aldehyde reductases and acetyl transferases respectively. The study of the kinetics of this metabolism and the expression patterns of the key enzymes can lead us to discover the specific compound(s), which is(are) the active priming agent(s).
We show here that corn plants, exposed to volatiles from ground-up leaves induce transiently JA and expression of the wound-induced lipoxygenase. Also, corn plants exposed to synthetic (Z)-3-hexenal or (Z)-3-hexen-1-ol convert either within minutes into (Z)-3-hexenyl acetate, suggestive that (Z)-3-hexenyl acetate is the main priming agent.
