Identification and characterization of PyAQPs from Pyropia yezoensis, which are involved in tolerance to abiotic stress
Aquaporins are a class of ancient channel proteins. The role of aquaporin proteins (AQPs) has been extensively studied in land plants. However, the information on AQPs in seaweeds is unclear. Pyropia yezoensis (Rhodophyta) grows in the intertidal zone and is believed to be a model research organism for seaweeds in the intertidal zone. In this study, we isolated two AQPs from P. yezoensis (PyAQPs) They contained two conserved Asn Pro Ala (NPA) motifs and six transmembrane a helices (H1 H6) Phylogenetic analysis showed that they are classified into two subfamilies, with much greater evolutionary distance with green plants. PyAQP1 belonged to the Glp group, whereas PyAQP2 belonged to a single small group. Subcellular localization showed that PyAQP1 was distributed on the plasma membrane of the cells, and PyAQP2 was mainly distributed in the plasma membrane and cytoplasm of the cells. The two genes displayed differential expression profiles for different abiotic stresses (desiccation, salinity, and temperature) at the mRNA and protein levels. Over expression of PyAQPs in yeast cells indicated that PyAQPs improved the growth of yeast under osmotic stress. These results provide an insight towards understanding the molecular mechanisms of P. yezoensis responding to stress.
Journal of Applied Phycology