A Novel Protein from sp. Improves Salinity and High Temperature Stress Tolerance in .

Brown alga sp. belongs to Phaeophyceae, a class of macroalgae that evolved complex multicellularity. sp. is a dominant seaweed in temperate regions, abundant mostly in the intertidal zones, an environment with high levels of abiotic stresses. Previous transcriptomic analysis of sp. revealed several genes consistently induced by various abiotic stresses; one of these genes is , which encodes a protein with unknown function. Bioinformatics analyses indicated that the protein encoded by is soluble and monomeric. The protein was successfully expressed in and In the gene was expressed under constitutive and stress inducible promoters which led to improved tolerance to high salinity and temperature stresses. The expression of several key abiotic stress-related genes was studied in transgenic and wild type by qPCR. Expression analysis revealed that genes involved in ABA-induced abiotic stress tolerance, K homeostasis, and chaperon activities were significantly up-regulated in the transgenic line. This study is the first report in which an unknown function sp. gene, highly responsive to abiotic stresses, was successfully expressed in , leading to improved tolerance to salt and temperature stress.