Water and ion transport in plants under salinity stress
Salinity stress is one of major abiotic stress that limit plant productivity in global agriculture. Salinity, usually high concentration of Na+, reduces water and mineral uptake in plant. I study root hydraulic conductivity (Lpr) using the root pressure chamber method, because regulation of Lpr is important to prevent dehydration and to cope with osmotic imbalance in initial phase of salinity stress. As for plant ion transporters, cRNAs are injected into a frog Xenopus oocytes and their properties (ion selectivity and activation mechanism) are investigated electrophysiologicaly to reveal what and how transporters regulate ion flux under salinity stress.
Aquaporins transporting water and low-molecular weight compounds
Aquaporins was first identified as a membrane protein exhibiting permeability for water when faced with an osmotic gradient. Now it is reported that several aquaporins facilitate the transport of not only water but also other low-molecular weight substrates such as glycerol, ammonia, silicic acid, arsenite, boric acid, and carbon dioxide. I study rice and barely aquaporins to improve plant growth and stress tolerance via aquaporin functions.