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SPECIAL SESSION: 18th I. E. Melhus Graduate Student Symposium: Molecular Basis of Plants, Pathogens, And Plant-Microbe Interactions: Today’s Students Build The Foundation for Next Level Plant Disease Resistance

Plants under attack: Maize phytohormonal crosstalk during multiple biotic stressors
Karen Ferreira Da Silva - University of Nebraska–Lincoln.

Plants have evolved multifaceted resistance mechanisms to overcome the attack by biotic stressors. Signaling networks among various phytohormones fine-tune plant resistance to pathogen and insect attack. It is well documented that the antagonistic interaction between jasmonic acid (JA) and salicylic acid (SA) appears widespread in various plant systems, while pathogens and herbivores use these defenses to trick the plants to acclimate for their own survival, depending on the plant/pest system. However, very little information is available regarding the underlying molecular mechanisms involving multiple biotic stressors on the same plant, and this is especially true for maize. Therefore, the objective of this project is to determine the role of phytohormonal crosstalk in maize plants invaded by Goss’s wilt and fall armyworm. Our RT-qPCR analysis indicate that there is an increased expression of genes involved in the SA pathway after 15 h of bacterial infection only, in both susceptible and resistant maize hybrids, although there was no difference in the expression of SA-related defenses in susceptible compared to resistant plants. We are currently monitoring how the expression of these genes can affect JA-pathway (crosstalk), and how that may impact the performance of subsequent herbivory by fall armyworm. The results of this research will improve our understanding and ability to predict the outcome of plant-mediated interactions involving multiple stressors. It also will contribute to modern breeding and molecular biology approaches to reduce our dependence on pesticides.