BREAD: Hybrid Technologies for Heterosis in Rice and Related Cereals

15 Apr 2010 30 Sep 2017

Stephen Dellaporta (PI) , Albert P Kausch (CoPI), Maria A Moreno (CoPI), Joseph Tohme Dr. (CoPI), Cesar P. Martinez Dr. (CoPI)


PI: Stephen L. Dellaporta, Yale University CoPIs: Maria A. Moreno (Yale University), Albert Kausch (University of Rhode Island), Joe Tohme and Cesar Martinez [International Center for Tropical Agriculture (CIAT)] Most plants, including rice and several major cereal crops, have perfect flowers that have both pistils and stamens. Maize, however, displays monoecy, having separate flowers with just pistils or stamens on the same plant. This floral partitioning promotes outcrossing and makes efficient hybrid seed production possible. Hybrid plants often show "heterosis", or hybrid vigor, a genetic phenomenon contributing to increases in biomass, yield, and disease and pest resistance as compared to their inbred parents. The goal of this project is to extend high throughput hybrid technologies to rice and other cereals using a variety of genetic and molecular approaches. One approach is to investigate monoecy genes of maize (tasselseed and silkless genes) in rice and cereal crops to understand functional differences that exist. A second approach is to exploit natural floral variation in related species to rice that exhibit degrees of monoecy. This variation (traits) will be mapped to specific genes and introduced into rice by inter-specific hybridization or transformation. The third approach is to create pistillate and staminate florets in rice by introducing transgenes capable of eliminating either pistils or stamens, thereby generating a synthetic system for hybrid seed production. At the basic scientific level, these studies will provide a deeper understanding of processes such as cell death, cell cycle arrest and hormonal regulation of flowering. Understanding the function of these monoecy genes in related cereals will provide information as to the origins of floral diversification in cereals.

BROADER IMPACT: Extending hybrid technologies to cereal crops such as rice with have a broader impact on human health and the environment. The lack of sufficient food supply remains one of the greatest challenges in the 21st century, comparable in mortality rates to the threat from emerging infectious diseases. Technologies for hybrid rice production, and associated increases in yields, will help to relieve hunger and famine in the world's poorest populations. Increasing yield through heterosis can have a beneficial environmental impact by minimizing the destruction of natural habitats as the world's population continues to multiply.

The project's educational component focuses on high school, undergraduate, graduate and postgraduate training opportunities in plant molecular biology and genomics. All three institutions will mentor undergraduate, graduate and postdoctoral students in research associated with the BREAD project. The project will sponsor several minority students from California State University at Fresno, a Hispanic-serving institution, in Yale's HHMI-sponsored Science, Technology and Research Scholars (STARS) summer program. The STARS program identifies underrepresented bioscience majors and mentors them into higher-than-average levels of performance. Two international students, recruited by CIAT from several Colombian universities, will be invited to join Yale's STARS program each summer. Lastly, outreach activities will be coordinated with the Peabody Museum at Yale, one of the largest public museum between New York and Boston visited by 110,000 people annually. The Museum's Evolutions (EVOking Learning and Understanding through Investigations of the Natural Sciences) serves high school students targeted from underserved populations from selected public schools. All sequence data will be released to GenBank and all biological materials, vectors and reagents generated will be available upon request through Yale and CIAT and can be accessed through a project website (to be developed).