Systemic defenses of soybean seeds within the plant and pods: The role of protease inhibitors against Nezara viridula (Hemiptera: Pentatomidae)

Title : Systemic defenses of soybean seeds within the plant and pods: The role of protease inhibitors against Nezara viridula (Hemiptera: Pentatomidae)

Abstract:

Soybean is the main oilseed cultivated in Argentina, constituting nearly half of the country’s production. The stink bug complex is the main pest of this crop, among which the Southern Green Stink Bug (Nezara viridula L.) stands out. Leveraging the natural resistance of plants can be an important way to reduce insecticide applications. Among soybean’s defenses are Protease Inhibitors (PIs), which deactivate digestive cysteine proteases in N. viridula’s guts, and are induced in pods and seeds following herbivory, causing the deactivation of the digestive enzymes cysteine proteases of the bugs. While many studies have explored local defense responses to insect damage, less is known about systemic mechanisms that enhance resistance in undamaged seeds. Stink bug herbivory increased PIs activity in both attacked and unattacked seeds within the same pod and different plant strata. Soybean pods respond systemically to herbivory by synthesizing PIs, even in undamaged seeds. Preference choice experiments showed that N. viridula preferred to feed on unattacked seeds rather than on unattacked but systemically induced pods. The systemic response of soybean alters feeding preferences of N. viridula likely by affecting the activity of their gut proteases, highlighting the potential of PIs in pest management strategies.

Biography:

Dr. Zavala is Full Professor of Biochemistry and Agricultural Zoology at the School of Agronomy, University of Buenos Aires and Principal researcher at CONICET. He studied Agronomy at the University of Buenos Aires, Argentina and earned his M.S. in 2000. He received his Ph.D. in 2004 and a two-year postdoc at the Max Planck Institute for Chemical Ecology in Jena, Germany. After a two-year postdoctoral fellowship at the University of Illinois at Urbana-Champaign supervised by Profs May Berenbaum and Evan DeLucia, USA. He obtained the position of Associate Professor at the University of Buenos Aires, School of Agronomy. He has published more than 70 research articles in SCI(E) journals. He is interested in plant defenses against insect attack, and how insects respond to plant defenses, using chemical, biochemical and ecological tools.