Project Groups in the Department of Insect Symbiosis

Host Plant Adaptation, © MPI CE / H. Vogel

Dr. Heiko Vogel

Insect‐plant interactions, exemplified by the constant arms race between host plants and their insect herbivores, provide an excellent opportunity to study the evolution of species interactions on molecular, ecological, and evolutionary levels. Food source is a major determinant for physiological performance in all living beings and a strong selection force for herbivores. The evolutionary success of phytophagous insects is largely dependent on their ability to utilize either many different food plants or their specialization towards specific host plants. While generalists face an array of different plant defenses (secondary plant compounds), and therefore need to likely invest in broad detoxifying strategies, specialist herbivores need to fine tune their adaptation to specific plant defenses. However, knowledge about the molecular mechanisms and evolutionary dynamics underlying specialist and generalist adaptation, host plant shifts and the potential for re-colonizing host plants is scarce or completely lacking.
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Group members: Maike Fischer (PhD student), PhD Yu Okamura (postdoc), Domenica Schnabelrauch (chemical engineer), Henriette Ringys-Beckstein (technician), Steffi Gebauer-Jung (bioinformatics)

Digestion, © MPI CE / Y. Pauchet

Dr. Yannick Pauchet

Larvae of herbivorous insects must ingest large amounts of plant material to achieve high growth rates during their lifetime. First, they have to cope with a recalcitrant physical barrier, namely the plant cell wall, to get full access to important nutrients insect larvae require to achieve their growth. Plant cell walls are composed of the most abundant biopolymers on the planet such as cellulose, hemicellulose, pectin (primary cell wall) and lignin (secondary cell wall). Some of these polymers are polysaccharides and represent a rich source of energy for insects which have evolved the ability to hydrolyze them. Second, insect larvae also face and have to adapt to high concentrations of plant defenses in their diet, such as proteinaceous inhibitors of digestive enzymes and toxic plant secondary metabolites. For an insect to successfully adapt to its host plant, its digestive system must overcome those plant defenses. During the course of evolution, a true ‘arms race’ has taken place between the insect digestive arsenal and plant defenses, leading to the emergence of large families of digestive and detoxifying enzyme genes. By combining molecular and biochemical approaches such as comparative transcriptomics and proteomics, as well as protein expression and characterization, our goal is to investigate in depth the mechanisms that contributed to the adaptation of the insect digestive arsenal to plant defenses and environmental stresses.
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Group members: Dr. Roy Kirsch (postdoc); Bianca Wurlitzer (technician); Wiebke Häger (PhD student); Pauline Sell (PhD student).

Dr. Tobias Engl

Animals live in a microbial world and engage in both mutualistic and antagonistic interactions with microbes. On the one hand, they often benefit from mutualistic associations with bacteria, fungi, and viruses, on the other one they need to keep microbial competitors and pathogens at bay. Microbial symbionts often directly support the host’s metabolism by providing limited or inaccessible nutrients. They are also able to ward off detrimental microbes via bioactive metabolites that complement the host’s own defenses or environmentally acquired medicinal compounds. In both cases, animals benefit from the unique metabolic potential of bacteria and fungi to synthesize primary or secondary metabolites beyond their own capabilities. The evolutionary background and trajectory, the ecological impact and functional organization of many of these symbiotic associations are still unknown. Combining experimental manipulation of symbiotic associations, sequencing technologies, analytical chemistry, and visualization of microbial partners and especially the involved metabolites allow us to elucidate these relationships.
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Group members: Julian Kiefer (PhD student, JGU Mainz), Noel Sillo (MSc student, JGU Mainz)
Co-supervision: Jürgen Wierz (PhD student), Nomthandazo Kanyile (PhD student), Chantal Ingham (PhD student, JGU Mainz), Marion Lemoine (PhD student)