Molecular ecology is an interdisciplinary research field which uses molecular techniques to elucidate the mechanisms behind ecological interactions. The Molecular Ecology group led by Prof. Dr. A. Steppuhn focuses on research in plant-insect interactions. Plants are literally on the bottom of the food chain, and they need to defend themselves against herbivores that want to eat them. We investigate how plants defend themselves against feeding herbivores and against the eggs that the herbivores deposit on the plant. In particular, we are asking how plants perceive that they are attacked, how they remember an attack or egg-deposition in the past and what strategies they use to fend off the attackers. We quantify the costs and benefits of the defenses under different environmental conditions, and investigate how they work on a mechanistic level. To achieve these tasks, we utilize a broad arsenal of methodology ranging from classical ecological field and greenhouse experiments over chemical analyses of plant metabolites (HPLC, GC/LC-MS) to molecular approaches including molecular cloning, sequencing and quantitative RT-PCR. Our research focuses on two model species, the wild tobacco Nicotiana attenuata and the bittersweet nightshade Solanum dulcamara.