NSF Award
1339237
PI: Georg Jander (Boyce Thompson Institute for Plant Research)<br/><br/>Senior Personnel: Tiffany Fleming (Boyce Thompson Institute for Plant Research)<br/><br/>ERA-CAPS collaborators: Matthias Erb (University of Bern, Switzerland), Monika Frey (Technical University of Munich, Germany), Inge Fomsgaard (Aarhus University, Denmark), and Jurriaan Ton (University of Sheffield, United Kingdom)<br/><br/>Maize (Zea mays), the world's most productive grain crop, is attacked by more than 90 species of insect herbivores. Although there is wide variation in maize resistance to herbivory, very little is known about the underlying genetic basis of these differences among maize cultivars. Genetic mapping, transcript profiling, insect bioassays, and biochemical approaches will be used to identify maize herbivore resistance genes. A particular focus area of this project will be the identification of biosynthetic and regulatory genes contributing to the production and transport of benzoxazinoids, a class of secondary metabolites with important defensive functions in maize, wheat, rye, wild barley, and other grasses. Research involving maize benzoxazinoid metabolism will provide a tractable model system for studying these agriculturally and ecologically important plant metabolites. Genetic mapping using a panel of diverse maize inbred lines will identify novel genes contributing to aphid and caterpillar resistance. Given the wide array of pests and pathogens against which maize plants protect themselves, there are likely to be interactions among the identified defense pathways. Defensive synergies and tradeoffs will be detected by comparing the genomic locations and biochemical functions of the identified maize genes that contribute to natural variation in herbivore resistance. <br/><br/>This project will lead to the identification of previously unknown maize genes that influence plant-herbivore interactions. Potential metabolic limitations and tradeoffs in maize defense against different classes of insect herbivores will be documented. It is anticipated that these expected results will open up new opportunities for using molecular breeding and transgenic approaches to improve herbivore resistance in maize, the most important agricultural crop in the United States. Research conducted through this project will help to train a new generation of students and postdocs for future careers in academia, industry, or government service. International research exchanges with the European ERA-CAPS (http://www.eracaps.org/) companion project entitled "Biosynthesis, transport and exudation of 1,4-benzoxazin-3-ones as determinants of plant biotic interactions (BENZEX)" will enhance the training of students and postdocs. Experiments involving maize-herbivore interactions will be fully integrated into an established education and outreach program at the Boyce Thompson Institute. Undergraduate students from throughout the United States will be recruited to be part of a ten-week summer internship program. In one-week training sessions, biology teachers from under-resourced schools will develop new plant science modules for their classes. Experimental kits for conducting caterpillar-feeding assays in local science classrooms will not only provide students with hands-on research experience, but also generate new information about the mechanisms of maize defense against insect herbivory. All data and resources generated through this project will be publicly accessible. A major output of this project will be a publicly available toolkit for studying the role of benzoxazinoids in maize defense against herbivores and pathogens. Seeds of near-isogenic lines and mutants will be deposited in the Maize Genetics Cooperation stock center, DNA clones will be available upon request and assay methods will be published in scientific journals. All DNA sequences will be deposited in public databases such as the NCBI SRA, Gramene, and MaizeGDB. Metabolite and metabolomics data will be deposited at METLIN (http://metlin.scripps.edu/). Education and outreach materials will be published and available for use via the Boyce Thompson Institute website (http://bti.cornell.edu/education/).
