Enhanced photosynthesis at low oxygen concentrations: Differential response of temperate and tropical grasses.

When leaves of grasses of the tribes Oryzeae, Festuceae, Hordeae, Aveneae, Phalarideae, Agrostideae and Stipeae were exposed to air containing a low oxygen concentration, photosynthesis was enhanced between 23 and 60%. No such increase was observed in grasses of the tribes Paniceae, Andropogoneae, Maydeae, Zoisieae, Chlorideae and Eragrosteae which are known (HATCH et al., 1967) to possess the C4 carbon pathway of photosynthesis. The latter group consists of tropical grasses and the former, except for the Oryzeae, are grasses of temperate regions.