The consequences of soil and above-ground herbivory on terpene diversity of a wetland grass

Wednesday, November 16, 2022

4:06 PM – 4:18 PM PT

Location: Vancouver Convention Centre, Meeting Room 213

Presenting Author(s)

Andrea Glassmire

Louisiana State University
Baton Rouge, Louisiana

Co-Author(s)

AS

Ana Salgado

Louisiana State University
Baton Rouge, Louisiana
Rodrigo Diaz

Louisiana State University
Baton Rouge, Louisiana
Michael J. Stout

Professor and Head
Louisiana State University
Baton Rouge, Louisiana
HL

Herie Lee

Louisiana State University
Baton Rouge, Louisiana
Alexander M. Gaffke

Postdoctoral researcher
USDA-ARS
Tallahassee, Florida
JC

James Cronin

Louisiana State University
Baton Rouge, Louisiana

The dieoff of Phragmites australis in the Mississippi River Delta is a multi-faceted problem and the invasive scale insect, Nipponaclerda biwakoensis, and soil microbes are suspected to be the central causes. Different phylogenetic lineages of Phragmites exhibit a gradient of resistance against the scale herbivory and soil microbes, with the North American native lineage being the most resistant and naturalized Delta being the most susceptible. We tested the hypothesis that the release of plant volatiles, a plant communication cue that is the first step in any plant-soil-insect interaction, will be dependent on the interactions among soil type, scales, and Phragmites lineage. Specifically, the emission of defensive volatiles will be reduced in die-off soils for the Delta lineage because beneficial microbes that are important for terpene production are lacking in die-off soils. We used a full factorial design where we manipulated soil type from healthy and die-off soils in the presence or absence of the scale insect from three lineages of Phragmites. We found that volatile emissions differed among lineages. The emission of terpene volatiles by Delta plants were strongly regulated by interactions between soil type and the scale. Overall, focusing on plant volatile cues will expand our understanding of plant traits that are resistant to die-off in certain Phragmites lineages.