Ascorbate−glutathione cycle involving in response of Bangia fuscopurpurea (Bangiales, Rhodophyta) to hyposalinity

Bangia fuscopurpurea is a widespread intertidal seaweed that commercially cultured in China. This frequently exposed to hyposalinity stress, but little known about the adaptation mechanisms. Ascorbate−glutathione (AsA−GSH) cycle plays important roles many organisms under variety of abiotic including hyposaline stress. In this study, we investigated response key metabolites and enzymes involved AsA−GSH B. hyposalinity, with addition exogenous GSH Lbuthionine-sulfoximine (BSO). The quantification BfAPX gene expression was assessed across varied treatment regimens. And putative interaction proteins were screened by yeast two hybrid system. It found (15 and/or 0 psu), content reduced glutathione (GSH), total (GSH+ oxidized glutathione, GSSG) cysteine, ratio GSH/GSSG ascorbic acid (AsA)/ dehydroascorbic (DHA), activity peroxidase (APX) monodehydroascorbate reductase (MDHAR) significantly up-regulated. hyposality-promoted weakened while (GR) promoted adding BSO. AsA/DHA strengthened dehydroascorbate (DHAR) had no significant changes either or without all salinities, DHAR together DHA enhanced APX markedly increased hyposalinity+BSO treatment. Putative interacting APX, glutamate dehydrogenase 1a fructose diphosphate aldolase, identified through screening. results indicated means increasing (through promoting biosynthesis pathway regeneration from GSSG GR catalyzation) (promoting AsA MDHAR). These findings would contribute improve aquaculture promising economic species unveil how seaweeds address global climate challenges.