Volatiles released by corn seedlings showing shade avoidance features are silenced after stink bug attack.

JACOBI, VANESA GISELA; FERNÁNDEZ, PATRICIA C. ; MADDONI GUSTAVO A; JORGE A ZAVALA

Buenos Aires

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

The Neotropical stink bug Dichelops furcatus F. (Hemiptera: Pentatomidae) has recently become a new pest of corn (Zea mays L.) in Argentina and Brazil. This stink bug species feeds on corn seedlings reducing the number of plants per hectare and crop yield. Volatile organic compounds (VOCs) released by corn seedlings in response to D. furcatus attack could recruit stink bugs’ natural enemies. Since plant-plant competition affects both plant growth and defenses, it is possible that VOCs released after herbivory can be adjusted to the photomorphogenesis changes. Corn plants perceive neighbor competition by phytochromes B1 (Phy B1) and B2 (Phy B2), and phytochrome B corn mutants show shade avoidance features in absence of plant-plant competition signals. In this study, we assessed VOCs emitted by seedlings of the wild type corn inbred line France 2 (WT) and its isogenic mutants lacking either Phy B1 or Phy B2 after D. furcatus damage. We collected and analyzed VOCs by using a coupled gas chromatography – mass spectrometry (GC-MS). We observed that Phy B1 mutant seedlings constitutively emitted higher amounts of indole, methyl salicylate and total volatiles than both, WT and Phy B2 mutant seedlings (p