CAREER: Development of an Integrative Seed Biology Program

Oregon State University, Corvallis OR

Investigators

Abstract

The goal is of this project aims is to establish a new, creative innovative research and education program for seed biology. This program The Integrative Seed Biology Program will consist of a new research project initiative on elucidation of the mechanisms of seed germination and development of a new curriculum for undergraduate and graduate teachingeducation. The research in this program will focus on the biochemical and molecular mechanisms of seed germination. Since the balance between the embryo growth potential and the resistance of the endosperm determines whether the radicle emerges, the research will focus on embryo- and endosperm-specific physiological events and the interaction between these two tissues. Tomato seed, which is a model system for germination research, and the seed of a model plant, Arabidopsis, will be used in this project. In these species, the endosperm must be weakened for germination to occur. In tomato seeds, endo beta mannanase is involved in endosperm weakening. The promoter of tomato germination-specific mannanase will be isolated using genome walk PCR and BAC library screening and analyzed using the beta?-glucuronidase (GUS) reporter gene. Since the mannanase gene is gibberellic acid (GA)-inducible, the GA-response motif(s) in the promoter will be determined by deletion analysis. In addition, as the germinative mannanase is expressed exclusively in the micropylar region of the endosperm (endosperm cap), the DNA motifs that are associated with this tissue-specific expression will be identified. This information will yield insights on how a specific gene is expressed at a specific location at an appropriate stage of development. A second area of research will identify the embryo-specific factors involved in germination in tomato and Arabidopsis seeds. Abscisic acid (ABA) inhibits germination but not endosperm weakening. Therefore, ABA is thought to affect the embryo and block germination. The embryo-specific factors that are suppressed (or enhanced) specifically by ABA will be isolated using the subtraction PCR method and their roles in seed germination identified. The educational part aspects of this program includes developing and undergraduate and graduate course in seed biology. TIn these classes will explore, basic phenomena in seed biology and recent outcomes fromcurrent breakthroughs in seed research. will be introduced in common terms, using many original slides. A seed biology web site will be created for public education. This site will serve as an international portal to the integrated seed biology resources and education activities for the public.