Grant: Research Tools and Instruments - Category 1 (<$150,000)

Organisms acquire some elements easily, such as O2, CO2 and H2O. But the acquisition of other elements, such as nitrogen (N) or micronutrients (metals), can be more difficult. N2 fixation, the biological reduction of N2(gas) to ammonium catalyzed by the enzyme nitrogenase in prokaryotes, is the main route of entry of new N into natural ecosystems. N2 fixation influences plant growth and carbon (C) exchange at local, regional and global scales. Since trace metal bioavailability, while potentially toxic, affects key enzymatic activities, such as that of nitrogenase, the cycling of metals in the environment can critically impact the cycling of major nutrients such as N or C. Despite the prime importance of micronutrients and N2 fixation in terrestrial ecosystems, the processes controlling their dynamics in the environment remain poorly understood. This poor understanding limits our capacity to manage present ecosystems and predict environmental responses to global climate change in a comprehensive manner. Deciphering micronutrient dynamics requires investigating processes occurring at the molecular level in model organisms under highly controlled conditions. The requested equipment will allow us to meet these requirements and pursue our fundamental research on micronutrient dynamics at the soil-plant interface. The requested equipment will also allow us to study the impact of global climate change, as simulated by elevated CO2, on micronutrient dynamics and on macronutrient (C, N) cycling in the environment. These results will provide new insights into ecosystem functions and contribute to better estimate the response of boreal forest to global warming.