Symbiosis with systemic fungal endophyte changes leaf litter volatiles in Lolium multiflorum

VENTURA, L; OMACINI M; FERNANDEZ, P

Congreso; 1st Joint Meeting ISCE/ALAEQ; 2016

Many grass species areassociated with maternally fungal endophytes that may provide chemical defensesagainst herbivorous insects. These chemical defenses are normally associatedwith the production of different types of alkaloids, which can protect plantsagainst vertebrate and invertebrate herbivores. Recent studies showed thatendophytic plants and their dead tissues (litter) conferred protection byassociation to neighboring plants to herbivores. The aims of this studywere to characterizethe volatile compounds emitted by plants with or without endophytes, and to determine the mechanism by which the presence of litter fromendophyte plants affects herbivore preference. We hypothesize that the presenceof fungal endophytes generates changes in litter volatile production thatreduces herbivore attraction. Here the volatiles released by leaf litterfrom Lolium multiflorum were analyzed by coupled gaschromatography-mass spectrometry. The volatile profile of endophyte andnon-endophyte leaf litter showed cuali-quantitative differences, supporting theidea that plants change their volatile profile in presence of a fungalendophyte. In order to evaluate the protective effect endophyte L.multiflorum litter on the foraging behavior of generalist hebivores onwillow leaves, dual choice experiments were performed with colonies of leafcutting ants, Acromyrmex ambiguous. We recorded feeding preference ofwillow leaves protected by 10 g of leaf litter from endophytic andnon-endophytic plants.  Ants collected irrespectively of the kind of leaflitter by which they were protected, indicating that these volatiles did notseem to affect their foraging behavior. This study showed that thepresence of endophytes in leavingplants, have an afterlife effect altering the volatile profile of leaf litterbut it did not seem to be the mechanism for affecting ants preference.