Abstract
Aquaporins are major membrane proteins, which facilitate membrane transport of water and other small molecules. Plasma membrane aquaporins (PIPs), especially PIP2 members, play a key role of intercellular water transport. Several studies have shown that PIPs response to environmental conditions and alter their expression or intracellular localization. We examined changes in mRNAs levels of PIPs under high temperature conditions.
Expression of 13 PIP genes in A. thaliana was quantified. The transcript level of only PIP2;3 among them was transiently increased in shoots and roots when the temperature rises to 30 degrees. The total protein level of PIP2;3, PIP2;1 and PIP2;2, which was determined immunochemically, was also increased at the high temperature similarly to the mRNA alteration. Therefore, we suggested that high temperature induces both the transcription and translation of PIP2;3. Both mRNA and protein abundances were decreased to the original levels when the temperature decreases. We estimate that this transient alteration of PIP2;3 is tightly related to physiological adaptation of plants to high temperatures.
