Elucidating the Genetic Architecture of ProVitamin A and Vitamin E Biosynthesis in Seed

Phenotypic variation of the majority of agronomically important crop traits is under polygenic control and understanding the genetic and molecular basis of natural variation within and between populations will be essential for connecting genes and alleles to phenotypes. Carotenoids and tocochromanols (tocopherols and tocotrienols) in plant-based foods are dietary sources of provitamin A and vitamin E and are required at minimum daily levels for optimal health in human and animal diets. To enhance our knowledge of the polygenic nature of these compounds in agricultural seeds, we plan to transfer and leverage information involving fundamental biological processes of carotenoid and tocochromanol biosynthesis from the model system Arabidopsis to the economically important crop maize. Using data from Arabidopsis, we will identify and annotate orthologs of the carotenoid and tocochromanol biosynthetic pathways in the maize genome. Whole genome and candidate gene association studies in both maize and Arabidopsis will be used to identify novel genes, functional variant alleles, and the genetic architecture of seed carotenoid and tocochromanol traits. Genetic mapping data from the two organisms will be integrated with expression data obtained from developing seeds using next generation whole transcriptome sequencing to delineate potential candidate genes responsible for carotenoid and tocochromanol traits. Through our integrated genetic, genomic, molecular, and computational approaches, we will be able to fine map and assess the molecular basis of epistatic interactions among known pathway genes and novel loci affecting these traits. Not only will this enable a comparative analysis of the genetic architecture of these traits between Arabidopsis, a dicot, selfing species with maize, a monocot, outcrossing species, but it will also be directly useful for improving vitamin content in maize through on-going breeding programs.

Understanding the molecular genetic basis of metabolic traits in agricultural seed crops that are essential for nutrition in humans and animals is a key component of meeting future global food and feed needs. Our research will provide a comprehensive genetic assessment of natural variation in two such biochemical pathways and will serve as a model for integrative analysis of natural variation of metabolism in multiple plant species. Data from the whole transcriptome sequencing generated in this study will greatly impact the maize research community as it creates a robust public resource for gene annotation, expression analyses, and polymorphism discovery. We will provide a unique environment for educating the next generation of scientists through engagement of high school, undergraduate, and graduate students as well as postdoctoral associates in research at interfaces of plant genetics, genomics, quantitative genetics and biochemistry. We will engage under-represented groups in plant scientific research through targeted recruitment of Hispanic undergraduates to the research programs at all four universities. Our outreach will include educating preschool children, K-12 students, and undergraduates in the concepts of genetics, plant breeding, biochemistry, nutrition, food sources and their relevance to diet and health. As vitamin deficiencies are a pervasive global health issue, an outcome of this research will be to provide the basis for more expedient and cost effective marker-assisted selection programs in maize for enhanced dietary levels of carotenoids and tocochromanols in the US and developing countries. Toward this end, we have established a network with researchers at CIMMYT, Mexico and IITA, Nigeria to facilitate seamless transfer of relevant results into active international breeding programs targeting developing countries.

The Maize Nutrigenomics website is maintained and hosted by the Buell Lab in the Plant Biology Department at Michigan State University.

What's New

15 January 2015

Search Tools -- A Maize QTL browser has been added, allowing you to view larger portions of the Maize genome at once. Also, we have added Maize and Arabidopsis GWAS data available for retrieval.

4 December 2014

BLAST Search -- Our BLAST Search page has been upgraded from WU-BLAST to NCBI-BLAST.

13 June 2013

Search Tools -- A searchable database with transcript and protein data from 25 maize genotypes is now accessible under the Search Tools tab. BLAST search is also now available.

Downloads -- Transcript and protein sequences for 25 maize genotypes are now available for download.

Maintenance Notice

We have planned server maintenance on the first Wednesday of every month. Web pages may be unavailable or only partially functional during server maintenance.