Rice Plants Sense Daily Weather and Regulate Aquaporin Gene Expressions in the Roots -Close correlation with potential evaporation-

抄録

　Transpiration, the evaporation from aerial parts of plants, is major driving force for the roots to uptake water from the soil. Aquaporins, the water channel proteins, are thought to play crucial roles in regulation of root hydraulic conductivity. Here we demonstrate that the evaporative demand plays a dominant role in the induction of specific aquaporins in rice (Oryza sativa) roots in seedlings grown hydroponically and then transferred to an open field. We found that the abundance of the root-specific aquaporin transcripts, OsPIP2;4, OsPIP2;5 and OsTIP2;1 at 8 a.m. is highly correlated with the evaporative demand in the morning (evaluated from potential evaporation averaged over 4 h before root sampling). Aquaporin isoforms with higher correlation to potential evaporation showed higher diurnal amplitude of their expression. Our study suggests that rice plants sense daily weather and responded to it by adjusting the expression of specific root aquaporin genes.