Did the First Angiosperms Lack an Embryo-Nourishing Endosperm? (An Accomplishment-Based Renewal)

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Principal investigator: William Edward FriedmanProposal number: IOS-0919986Proposal title: "Did the First Angiosperms Lack an Embryo-Nourishing Endosperm?"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The origin of flowering plants represents one of the most significant evolutionary radiations of plants during the last 475 million years. With over 250,000 extant species, angiosperms are the largest and most diverse group of plants to have evolved. It has long been assumed that the first flowering plants formed a nutrient-storing and embryo-nourishing tissue called endosperm that is derived from a second fertilization event during the process of double fertilization. Indeed, many evolutionary biologists have suggested that endosperm represents a key innovation associated with the ecological and evolutionary ?success? and radiation of flowering plants. Although poorly studied, there is fragmentary evidence that many of the most ancient lineages of angiosperms do not rely upon an endosperm as the primary embryo-nourishing tissue within the seed. It is the explicit goal of the project to study the embryological processes within seeds of ancient extant lineages of flowering plants in order to reconstruct the pattern of embryo-nourishing behavior of the first angiosperms. The comparative developmental data to be derived from this project have the potential to lead to the discovery of a "missing link" associated with the transition from the ancestors of flowering plants to the earliest angiosperms. Among the broader impacts of this project, it should be noted that two out of every three calories consumed by humans worldwide are derived from the endosperm of flowering plants (e.g., rice, maize, barley, wheat, coconut). Thus, examination of seed development in ancient lineages of angiosperms will provide basic biological information that may ultimately be relevant in an applied and agricultural context. In addition, the questions to be addressed in this project are sufficiently basic to warrant the expectation that the findings will contribute to undergraduate and graduate curriculum development at the national and international levels, as has been the case in the past. Discoveries from this project can be expected to be widely disseminated to the general public. During the last grant cycle, research findings were publicized in a number of media outlets including CBS News, USA Today, Natural History Magazine (invited article), New Scientist, Science News, the Telegraph (U.K.), as well as a variety of websites from around the world. Finally, this project can be expected to contribute to the development of human resources in the sciences and the advancement of members of underrepresented groups in the sciences. The Friedman lab has consistently included a high proportion of women and members of underrepresented groups, all of who aspire to careers in the life sciences as educators (two recent members of the lab have gone on to teach secondary science in public schools) and/or practicing scientists (the most recent Ph.D. student to graduate is Hispanic). In essence, while the vast majority of funds associated with this project will go to support the solution of basic and longstanding scientific questions, these funds will also be central to the development of a few of the next generation of biologists and teachers.