Research Interests

Biochemistry and Biology of Plant Volatiles

Principally all plants produce volatile organic compounds (VOCs) that play important roles in their communication with the environment. These interactions include defense responses against microorganisms and herbivorous insects and the attraction of pollinating insects or parasites and predators of insect pests.
The Tholl lab investigates volatile terpenes, which represent a major class of plant volatiles, in the model plant Arabidopsis thaliana. We are employing biochemical, molecular and genomic tools to study the biosynthesis of these volatiles and explore their physiology and ecological significance in above- and belowground plant tissues.

Enzymology and regulation of insect-induced terpene volatile biosynthesis

Many plants including important crop species such as maize, cabbage, tomato and cucumber emit volatile terpenes in response to insect or pathogen-attack. These compounds can attract natural enemies of insect pests and hence act as airborne “alarm calls”. C11- and C16- homoterpenes are among the most common volatiles emitted in response to insect-feeding. The Tholl lab investigates the biosynthetic pathways in the formation of these important plant volatiles and determines their cellular and metabolic regulation in different Arabidopsis tissues. These studies will provide new information with significance for engineering of volatile metabolism in an effort to develop alternative pest controls.

Biochemistry and function of root volatiles

There is growing evidence for the role of terpene volatiles as chemical signals in belowground plant-organism interactions such as anti-microbial defense or the attraction of insect-parasitizing nematodes upon insect-feeding on roots. We analyze terpene biochemistry in Arabidopsis roots to gain information concerning the cell-specific and subcellular formation of volatiles in roots. Furthermore, we are interested in how terpene volatile formation is regulated in response to attack by soil-borne herbivores and fungal root-pathogens and ask whether these compounds act as signals that attract plant- and insect-parasitizing nematodes.

Volatile terpenes as internal signals or regulators

The use of gaseous (volatile) molecules that freely diffuse across cell membranes is a main principle in signal transmission and cell regulation in biological systems. Surprisingly little is known about the cellular activities of VOCs at wound or infection sites prior to their emission. The Tholl lab explores potential internal functions and dynamics of common plant volatiles by investigating the role of volatile terpenes in defense responses in the Arabidopsis model.