Activation energies (Ea) of water transport in V. vinifera aquaporins expressed in yeast.

(A) Arrhenius plot of Pf at temperature range (9–37°C), where T is temperature in Kelvin. Ea was evaluated from the slopes. Strains expressing VvTnPIP1;4, VvTnTIP4;1 and empty plasmid (pUG35) showed steeper slope, while strains expressing VvTnPIP2;1, VvTnTIP1;1 and VvTnTIP2;2 exhibited shallow slope. (B) Calculated Ea from the slope showed that VvTnPIP2;1, VvTnTIP1;1 and VvTnTIP2;2 expressing strains exhibited lower Ea, while VvTnPIP1;4, VvTnPIP2;3 and VvTnTIP4;1 expressing strains showed were almost equal to control strain (pUG35). Data are mean ± SD of three independent experiments with at least five traces (ten traces in case of Pf at 23°C) at each temperature.