AtTIP1;3 and AtTIP5;1, the only highly expressed Arabidopsis pollen-specific aquaporins, transport water and urea.
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.
Soto
Gabriela
G
Instituto de Ingeniería Genética y Biología Molecular (INGEBI-CONICET), Vuelta de Obligado 2490 Piso 2, C1428ADN Buenos Aires, Argentina.
Alleva
Karina
K
Mazzella
María Agustina
MA
Amodeo
Gabriela
G
Muschietti
Jorge P
JP
D000818:Animals; D020346:Aquaporins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000096:biosynthesis* / Q000235:genetics; D001692:Biological Transport / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D011058:Pollen / Q000378:metabolism*; D014158:Transcription, Genetic; D014508:Urea / Q000378:metabolism*; D014867:Water / Q000378:metabolism*; D014981:Xenopus
D020346:Aquaporins; D029681:Arabidopsis Proteins; C535168:TIP1;3 protein, Arabidopsis; C535169:TIP5;1 protein, Arabidopsis; D014867:Water; D014508:Urea