Abstract
Discovery of aquaporin (water channel) genes have facilitated investigations into the molecular mechanisms of cellular water permeability and transport. We isolated genes of plasma-membrane type aquaporins in barley roots and demonstrated the water transport activity, tissue localization, and diurnal change in expression of a particular aquaporin, HvPIP2;1, in barley. Over-expression of HvPIP2;1 increased the shoot/root ratio and raised salt sensitivity in transgenic rice plants. Furthermore, we noticed the increase in internal CO2 conductance of transgenic plants. This finding indicated that HvPIP2;1 can facilitate permeation of a CO2 as well as water molecule.
