D3068: Fall armyworm (Spodoptera frugiperda) oral secretions modulate defense responses in sorghum

Plants have evolved complex defense mechanisms to defend themselves against frequent insect attack. The phenylpropanoid biosynthesis pathway synthesizes wide range of compounds, which can provide protection against insect herbivores. However, the role of sorghum phenylpropanoids in providing defense against the invasive pest, fall armyworm (FAW), Spodoptera frugiperda, has not been explored yet. Along with feeding damage, caterpillar release oral secretions (OS) which are recognized by plants to elicit defense response. Our results indicate that the FAW infestation altered the expression level of genes involved in the monolignol biosynthetic pathway. Further, we examined the role of FAW OS in triggering plant defenses. Application of FAW OS on wounded sorghum leaves elevated the expression of genes involved in the monolignol biosynthetic pathway. Overall, our study suggests that FAW OS trigger herbivore defenses in sorghum.