AtTIP1;3 and AtTIP5;1, the only highly expressed Arabidopsis pollen-specific aquaporins, transport water and urea

Soto, Gabriela; Alleva, Karina; Mazzella, María Agustina; Amodeo, Gabriela; Muschietti, Jorge P.

doi:10.1016/j.febslet.2008.11.002

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Volume 582, Issue 29 , Pages 4077-4082, 10 December 2008

AtTIP1;3 and AtTIP5;1, the only highly expressed Arabidopsis pollen-specific aquaporins, transport water and urea

Edited by Julian Schroeder

Gabriela Soto
- Instituto de Ingeniería Genética y Biología Molecular (INGEBI-CONICET), Vuelta de Obligado 2490 Piso 2, C1428ADN Buenos Aires, Argentina
Karina Alleva
- Laboratorio de Biomembranas, Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
María Agustina Mazzella
- Instituto de Ingeniería Genética y Biología Molecular (INGEBI-CONICET), Vuelta de Obligado 2490 Piso 2, C1428ADN Buenos Aires, Argentina
Gabriela Amodeo
- Laboratorio de Biomembranas, Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
Jorge P. Muschietti
- Instituto de Ingeniería Genética y Biología Molecular (INGEBI-CONICET), Vuelta de Obligado 2490 Piso 2, C1428ADN Buenos Aires, Argentina
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Corresponding author. Address: Instituto de Ingeniería Genética y Biología Molecular (INGEBI-CONICET), Vuelta de Obligado 2490 Piso 2, C1428ADN Buenos Aires, Argentina. Fax: +54 11 4786 8578.

Received 4 September 2008; received in revised form 4 November 2008; accepted 5 November 2008. published online 17 November 2008.

Abstract

Pollination includes processes where water and/or solute movements must be finely regulated, suggesting participation of aquaporins. Using information available from different transcriptional profilings of Arabidopsis thaliana mature pollen, we showed that the only aquaporins that are selectively and highly expressed in mature pollen are two TIPs: AtTIP1;3 and AtTIP5;1. Pollen exhibited a lower number and more exclusive type of aquaporin expressed genes when compared to other single cell transcriptional profilings. When characterized using Xenopus oocyte swelling assays, AtTIP1;3 and AtTIP5;1 showed intermediate water permeabilities. Although they displayed neither glycerol nor boric acid permeability they both transported urea. In conclusion, these results suggest a function for AtTIP1;3 and AtTIP5;1 as specific water and urea channels in Arabidopsis pollen.

Keywords: Arabidopsis, Tonoplast aquaporin, Pollen tube, Solute transport, Urea, Pollen hydration