Water channel required to facilitate the transport of water across cell membrane. May be involved in the osmoregulation in plants under high osmotic stress such as under a high salt condition. Transports urea in yeast cells in a pH-independent manner. Transports H(2)O(2) in yeast cells. Interacts with cucumber mosaic virus (CMV) Protein 1a. Tonoplast. Widely expressed. Predominantly expressed in roots. Starts to be expressed in seedlings from 2 days ays after germination. By NaCl and abscisic acid (ABA) treatments. Aquaporins contain two tandem repeats each containing three membrane-spanning domains and a pore-forming loop with the signature motif Asn-Pro-Ala (NPA). Belongs to the MIP/aquaporin (TC 1.A.8) family. TIP (TC 1.A.8.10) subfamily. Duplication of 20 AA in position 80.