2006 Annual Report 1.What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? Why does it matter? The research in this project is relevant to NP 302, "Plant Biological and Molecular Processes." We are attempting to understand the regulation of ethylene biosynthesis at the level of the ACC synthase (ACS). Furthermore, we want to elucidate how auxin regulates ethylene biosynthesis at the level of ACS activity. Understanding how ethylene production is regulated at the molecular level will allow the construction of plant species with regulated ability to senescence during various stages of plant development. Ethylene is the hormone responsible for plant senescence and aging. Fruits, vegetables and intact plants produce ethylene through their lives in a tissue specific and developmental manner. If we can control ethylene production throughout the life of a plant, we will be able to obtain fruits that do not ripen fast, vegetables that last longer and plants that live longer and have a higher yield. We use tomato, pea and Arabidopsis to advance our goals. Foundamental knowledge obtained by the reference plant Arabidopsis is translated into knowledge that advances agronomical important plants such as tomato and pea (legumes). In addition our research efforts have the potential to engineering plants that produce large amounts of ACC for commercial ethylene production to be used for production of plastics and other industrial products. Currently, ethylene is produced by catalytic cracking of petroleum which is of finite amount. The long-term goal of this research is to define the molecular mechanisms by which the biosynthesis of the plant hormone ethylene is regulated during plant growth and development. We want to understand the biological function of the various ACS genes and their regulation by the hormone auxin. Furthermore elucidation of the total enzymatic capacity for ethylene production in a single cell is of paramount importance for regulating ethylene production in an intelligent manner during growth. 2.List by year the currently approved milestones (indicators of research progress) YEAR 1 (FY 2006/2007) 1. To determine the ethylene biosynthetic capacity of the tomato plant. We will determine whether the tomato ACS isozymes have the capacity to heterodimerize using functional intermolecular complementation and Bimolecular Fluorescence Complementation (BiFC) in E.coli. We will also determine the biochemical properties of the active homo- and heterodimeric isozymes. 2. To determine some of the molecular details of the regulation of the tomato genes by the hormone auxin. The Auxin Response Factors (ARF) that regulate their auxin-inducibility will be identified and tested whether affect plant senescence. YEAR 2 (FY 2008) 1. To determine the ethylene biosynthetic capacity of the tomato plant. We will determine whether the tomato ACS isozymes have the capacity to heterodimerize using functional intermolecular complementation and Bimolecular Fluorescence Complementation (BiFC) in E.coli. We will also determine the biochemical properties of the active homo- and heterodimeric isozymes. 2. To determine some of the molecular details of the regulation of the tomato genes by the hormone auxin. The Auxin Response Factors (ARF) that regulate their auxin-inducibility will be identified and tested whether affect plant senescence. YEAR 3 (FY 2009) 1. To determine the ethylene biosynthetic capacity of the tomato plant. We will determine whether the tomato ACS isozymes have the capacity to heterodimerize using functional intermolecular complementation and Bimolecular Fluorescence Complementation (BiFC) in E.coli. We will also determine the biochemical properties of the active homo- and heterodimeric isozymes. 2. To determine some of the molecular details of the regulation of the tomato genes by the hormone auxin. The Auxin Response Factors (ARF) that regulate their auxin-inducibility will be identified and tested whether affect plant senescence. YEAR 4 (FY 2010) 1. To determine the ethylene biosynthetic capacity of the tomato plant. We will determine whether the tomato ACS isozymes have the capacity to heterodimerize using functional intermolecular complementation and Bimolecular Fluorescence Complementation (BiFC) in E.coli. We will also determine the biochemical properties of the active homo- and heterodimeric isozymes. 2. To determine some of the molecular details of the regulation of the tomato genes by the hormone auxin. The Auxin Response Factors (ARF) that regulate their auxin-inducibility will be identified and tested whether affect plant senescence. YEAR 5 (FY 2011) 1. To determine the ethylene biosynthetic capacity of the tomato plant. We will determine whether the tomato ACS isozymes have the capacity to heterodimerize using functional intermolecular complementation and Bimolecular Fluorescence Complementation (BiFC) in E.coli. We will also determine the biochemical properties of the active homo- and heterodimeric isozymes. 2. To determine some of the molecular details of the regulation of the tomato genes by the hormone auxin. The Auxin Response Factors (ARF) that regulate their auxin-inducibility will be identified and tested whether affect plant senescence. 4a.List the single most significant research accomplishment during FY 2006. The research in this project is relevant to NP 302, Component 2, Problem Statement 2A, "Understanding Growth and Development." This project started April 1, 2006 and replaced project 5335-21000-005-00D. Please see the report for project 5335-21000-005-00D. 4b.List other significant research accomplishment(s), if any. NONE. 4c.List significant activities that support special target populations. NONE. 4d.Progress report. NONE. 5.Describe the major accomplishments to date and their predicted or actual impact. The research in this project is relevant to NP 302, Component 2, Problem Statement 2A, "Understanding Growth and Development." This project started April 1, 2006 and replaced project 5335-21000-005-00D. Please see the report for project 5335-21000-005-00D. 6.What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end-user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products? This project started April 1, 2006 and replaced project 5335-21000-005-00D. Please see the report for project 5335-21000-005-00D. 7.List your most important publications in the popular press and presentations to organizations and articles written about your work. (NOTE: List your peer reviewed publications below). This project started April 1, 2006 and replaced project 5335-21000-005-00D. Please see the report for project 5335-21000-005-00D.