Nutrient availability can limit plant growth and productivity. Plants need the micronutrient copper to perform photosynthesis, the process in which sunlight is used in order to fix carbon dioxide from the atmosphere and which is responsible for all biomass formation on the planet. However, copper is also required for other processes, next to photosynthesis. Therefore, when this element is available in limiting amounts in the soil, choices must be made by the plant about how to best use this precious resource. It was found that the transport systems that control how copper is used within the cells of a plant leaf are regulated by the amount of copper that is available. The mechanism of regulation involves a copper-controlled selective degradation of a copper transporter within the photosynthetic sub-cellular compartment. This finding implies that plants can selectively sense the amount of copper that is available in various cellular compartments within a leaf and that this information in turn is used to control specific protein stability. Such a mechanism had not been observed before in nature and this research is aimed at identifying the cellular machineries that can sense copper and that control transporter turnover. Implications of this regulatory process for photosynthetic productivity will be tested. How micronutrient availability affects the assembly of the photosynthetic machinery is a fundamental question in cell biology that has to be addressed.
BROADER IMPACTS
Photosynthesis is the process which drives all of life on earth. A better understanding of how the photosynthetic machinery is assembled will allow people to make better decisions regarding the use of fertilizers and copper-based fungicides, thus benefitting the environment and potentially improving agricultural productivity, especially on soils that are marginal. The research also has potential impact for biofuel production in which optimal photosynthetic activity is required. The project will train a group of young scientists including undergraduate students at Colorado State University and includes an outreach component for local elementary schools in the form of modules about plant biology and photosynthesis.
