Exploring the nexus of Nitrogen and Carbon utilization and its role in plant growth and the transition to reproductive development

点击翻译按钮获取中文摘要

Summary for Public Release Worldwide crop production is under considerable stress due to several factors, including population growth, increased crop use per person, increasing atmospheric CO2 and other environmental issues. A major challenge is to increase global crop yields in an economically and environmentally sustainable fashion. A key limiting factor and single largest input cost for many crops is nitrogen (N). Whereas prohibitive fertilizer costs in developing countries leads to lower yields, use of large amounts of N fertilizer causes significant and irreversible environmental damage. Thus, a better understanding of how crops use nitrogen will lead to technology that can enhance crop productivity and would markedly reduce costs and increase yields for farmers of all nations. How plants sense and assimilate N occupies a central node in a complex meshwork of interacting processes. This research focuses on specific nodes of this network to clarify how plants integrate N levels to maximize plant growth. A particular aim of this study is to analyse the functions of two genes involved in distinct yet overlapping nodes. 1) The ENOD93 family genes modulate how plants sense N and transmits this information to coordinate plant growth and flowering time with nutrient availability, which is directly correlated with yield. In preliminary studies, we find that altering activity of ENOD93 genes in different plant species, including important crop plants such as rice, results in improved plant growth with lower N input. 2) Similar to ENOD93, the GATA12 genes regulate growth under different N levels to coordinate growth traits such as flowering time and biomass production. Determining how these genes function, alone or together, will provide insights into the larger genetic network that coordinates nutrient uptake with plant growth. Accordingly, understanding of the underlying mechanisms controlled by these genes could bring to light new and incisive ways to create better crop plants. A general consensus among researchers studying the complexities plant growth is that there is much room for improvement with regard to how plants use nutrients to create biomass and, thus, yield. Improving the efficiency of this process is a vital first step to creating better crops with fewer negative consequences. The ultimate outcome of this research will be to provide knowledge that leads to the production of crop plants needed to feed the majority of the world population with less environmental damage.