Adaptation of insect herbivores to plant defense: Genome-wide transcriptional responses of the lepidopteran midgut to changes in plant defense chemistry

• Applicant: Dr. Marco Herde
• Subject Area: Plant Cell and Developmental Biology
• Term: from 2009 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 135926291

Higher plants produce myriad proteins and specialized metabolites that target various aspects of insect digestive physiology. In contrast to our knowledge about these host defense mechanisms, relatively little is known about the strategies employed by insects to overcome plant defenses. The major objective of this proposal is to employ modern sequencing and transcriptional profiling technologies to investigate the hypothesis that insect herbivores adapt to changes in leaf chemistry by reconfiguring their midgut physiology. The specific aims of the project are: (i) to perform deep sequencing of the midgut transcriptome of the lepidopteran generalist Trichoplusia ni, and to use this sequence information to design a comprehensive microarray of midgutexpressed T. ni genes; (ii) to use this microarray platform to identify global changes in the midgut transcriptome of T. ni larvae reared on diverse host plants; (iii) to identify T. ni genes that are differentially expressed in response to the jasmonate-based defense system in Arabidopsis thaliana and Solanum lycopersicum; and (iv) to identify T. ni genes that are differentially expressed in response to individual plant defense compounds. Results from these experiments will provide an unprecedented, genome-wide view of how insect midgut physiology is modulated in response to changes in host plant chemistry, and will establish a foundation for future functional analyses of genes and signaling events that control insect adaptation to plant defense compounds. Because pest control strategies that rely on “built-in” plant defenses are often limited by the ability of insects to effectively adapt to these compounds, the identification of insect genes that are triggered by changes in leaf chemistry may facilitate the discovery of novel approaches for pest control.

• DFG Programme: Research Fellowships
• International Connection: USA
• Host: Professor Dr. Gregg A. Howe