Metal cations in CO₂ assimilation and conversion by plants

Green leaf tissues convert solar energy into the energy of chemical bonds of sugar molecules during the process of photosynthesis. The efficiency of this conversion can be much higher than the efficiency of any of the currently known silicon-based solar panels. Importantly, vast amounts of CO₂ are assimilated during this process. The efficiency of photosynthesis is critically dependent on the availability of a large number of nutrients, among which metal cations such as K, Ca, Mg, Cu, Zn, Fe, Mn, and Ni play a key role. This paper summarizes the basic requirements and major functions for each of these essential nutrients in plant photosynthesis, both at the whole-plant and molecular level. Also discussed is how these requirements may be affected by the global climate trends and the prospects of creating artificial photosynthetic "bioreactors" for efficient energy conversion and CO₂ assimilation.