The mode of action of insecticidal acylurea compounds in the red flour beetle Tribolium castaneum

• Applicant: Professor Dr. Hans Merzendorfer
• Subject Area: Animal Physiology and Biochemistry
• Term: from 2011 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 191088255

Acylurea compounds are highly potent insecticides that selectively inhibit chitin synthesis. Insecticide potency derives mainly from defects in chitin formation and its consequences of an abnormal endocuticular deposition and abortive molting. Today, acylureas play an important role in integrated pest management. Although it is well established that acylureas interfere in chitin synthesis, the precise mechanism of action is unknown. Several lines of experiments argue that acylurea compounds do not directly inhibit catalysis as evinced in cell-free chitin synthesizing insect systems. Rather than inhibiting the chitin synthase directly, acylureas may alter either vesicle transport or fusion, block the substrate supply for the chitin synthase, inhibit translocation of chitin polymers across the membrane or interfere in the hormonal regulation of chitin synthesis by influencing ecdysteroid production. Our previous studies revealed that the stored product pest Tribolium castaneum (red flour beetle) is a good model organism for investigating the mode of action of bioactive materials such as acylurea and other insecticides. We propose a comprehensive study utilizing genomic, proteomics, biochemical and immunological approaches to clarify the mode of action of insecticidal acylurea compounds.

• DFG Programme: Research Grants