RUI: The Function and Regulation of Invertase Inhibitors during Early Seed Development in Arabidopsis

Spelman College, Atlanta GA

Investigators

Abstract

Seed is a major renewable resource for the production of food, feed, energy, and industrial materials. Proper seed development relies on the nutrients imported from the maternal plant, as well as appropriate nutrient allocation among the three seed compartments, the embryo, the endosperm, and the seed coat. Very little is known about how nutrient allocation is regulated at the interface between the endosperm and the embryo. This project will investigate how two genes expressed in the endosperm influence the rate of sugar transport to the embryo. The outcome of the project will advance our knowledge on the genetic mechanisms that control seed size, which will be applicable to the improvement of yield and grain quality in crop species. This project will enhance research capacity and improve undergraduate STEM education through the integration of research and teaching at a women's liberal arts college for African Americans. Undergraduate students will be recruited to conduct independent research in the PI's lab. The project is expected to improve the recruitment of minority and women students into STEM disciplines. It is well known that the timing of endosperm cellularization affects embryo growth rate. However, the underlying molecular mechanism has remained largely unexplored. This project will test the hypothesis that the Polycomb Repressive Complex 2 (PRC2) represses the expression of invertase inhibitor (InvINHs) genes to regulate sugar allocation between the endosperm and the embryo. The specific aims are to establish the causality between InvINHs and the suppression of embryo growth through genetic manipulation, and to identify the cis-elements and the transcription factors that regulate InvINHs expression. The proposed activity is expected to establish how a master regulator of endosperm cellularization, the PRC2 complex, regulates nutrient allocation between the embryo and the endosperm via the repression of InvINHs. A deeper understanding of this connection will allow us to further investigate how modifications in the endosperm developmental program have shaped the evolution of seed morphology.