Herbivory of stink bugs Nezara viridula, Dichelops furcatus and Piezodorus guildinii induces emission of volatiles organic compounds in soybean (Glycine max).

IRIGOYEN BODARAMPÉ GERARDO; ZAVALA J. A

Buenos Aires

Congreso; 6th Congress of the Latin American Association of Chemical Ecology; 2021

The stink bug complex formed by Dichelops furcatus, Nezara viridula and Piezodorus guildinii is one ofthe primary soybean pests that feed in developing seeds, causing massive economic losses in SouthAmerica. In response to insect herbivory, soybean synthesizes and emits a blend of volatile organiccompounds (VOCs) from their leaves, which act as host-location cues for natural enemies of stink bugs.This systemic induction of defenses starts with the synthesis of LOX enzymes in the seeds, which areNHHQ]PHVWRMDVPRQLFDFLG-$VQWKHVLVWKDWUHJXODWHV92&V¶VQWKHVLV$OWKRXJKHPLWWHG92&Vfrom soybean grown in controlled environments have been thoroughly characterized, little is knownabout the emission of VOCs in field-grown soybean. In the present study, we studied VOCs emittedconstitutively or induced in response to herbivory of D. furcatus, N. viridula and P. guildinii in field-grownsoybeans. While undamaged plants did not emit VOCs, herbivory treatment increased emission of theVHVTXLWHUSHQHĮ-farnesene. Although after herbivory of N. viridula plants emitted only two volatiles, D.furcatus and P. guildinii attack induced emission of five and eight VOCs, respectively, including thegreen leaf volatile (Z)-3-Hexenyl acetate. Additionally, we determined the expressión of LOX genes(LOX-1, LOX-2, LOX-3) through qPCR in undamaged and stinkbug damaged seeds. Although we didnot detect any change of gene expression in undamaged or mechanically damaged seeds, expressionof LOX1 gene was up-regulated more than twenty folds after herbivory. This study suggests that fieldgrown soybeans recognize attacks from stink bug species and respond accordingly, emitting a dissimilarblend of VOCs.