D3276: Examining the impact of flooding stress on maize plant’s defensive traits against insect herbivores

Flooding is one of the most important abiotic stresses experienced by plants, which causes substantial yield losses. By far, many studies have been conducted to determine the impacts of flooding stress on crop growth and hence on the yield. However, how this abiotic stress can alter the above-ground interactions of plants with herbivores insects is very less understood, especially in the field conditions. To address this question, we designed a multi-year field experiment by growing two hybrids of maize crop undergoing three treatments- no flooding/control, single flooding, and double flooding. We sampled plants to analyze secondary defensive metabolites (total phenolic content). The phenolic content analysis from early-stage samplings shows a differential response of total phenolic content to the flood treatments, with the flooded plants having significantly higher total phenolic content as compared to the non-flooded plants. This difference is also specific for hybrids, with one hybrid having higher content than the other, suggesting the importance of genotype differences in plant defenses. These initial findings provide us with a strong baseline framework of possible consequences of flooding stress on the insect- plant interactions by altering its defensive compounds. As we continue to explore this, our future studies are intended to investigate the response of flooded plants, directly on the growth and development of insect herbivore, Spodoptera frugiperda. Our study can help us unravel the plant responses to flooding stress and how these responses are related to the plant-insect interactions.