Functional Study of Pollen-Specific Aquaporins In Arabidopsis thaliana

G. SOTO, M. SUTKA, G. AMODEO, A. MAZZELA A AND J MUSCHIETTI

Iguazú, Misiones, Argentina

Congreso; XL Reunión Anual de la Sociedad Argentina de Investigaciones Bioquímicas; 2004

SAIB

The first step for an efficient pollination and fertilization is the hydration of pollen grains, suggesting that the movement of water through the pollen grain is a physiologically regulated process that does not depend only on osmolarity and water potential differences. Aquaporins may be involved in this regulation, increasing the water movement through the pollen grain membrane. Using available information about Arabidopsis thaliana´s loci (www.arabidopsis.org) which shows high homology with aquaporin genes and also analyzing available transcription data of tissue specific arrays (http://affymetrix.arabidopsis.info), we selected four pollen-specific loci (At3g47440, At4g01470, At5g37810 and At3g04090) homologous to aquaporin genes. We measured volume changes in Xenopus leavis oocytes injected with the four different aquaporin cRNAs. We will assess the importance of these four aquaporin genes in the proposed pathways, isolating mutant homozygote plants for all these genes and then cross them to obtain double, triple and quadruple mutants. We will analyse their in vitro germination pollen ability and also the fertility of these plants evaluating the number and viability of obtained seeds. We will test for the localization of aquaporin proteins in pollen grains by transforming plants with a construct in which the LAT52 promoter is driving expression of the aquaporin proteins tagged with a Cterminal GFP fusion.