Abstract
We isolated a lily aquaporin gene, AqpL1, from lily petal using RT-PCR. Phylogenetic analysis showed that AqpL1 was a member of PIP1 subfamily. AqpL1 gene could be properly expressed by in vitro translation and showed a 26 kDa monomer band revealed by autoradiograph. Injection of AqpL1 cRNA into Xenopus oocytes resulted in an increase of the osmotic water permeability (Pf= 0.72●10-3 cm/s) for about 2-3 times compared to that (Pf=0.24●10-3 cm/s) of the cells injected with water. Overexpression of AqpL1 in tobacco could improve the content of aquaporin in the cells revealed by Western blotting, and subsequently resulted in a great increase of the osmotic water permeability of leaf protoplasts ( 0.7●10-2 cm/s vs 4.3●10-2 cm/s ) and water conductivity of leaf cells (8.3% vs 23.2%). The results of Northern hybridization indicated AqpL1 expressed in whole plant but it strongly expressed in young petal and remarkably decreased with flower age.
