Transcriptomic and lipidomic analysis reveals the salt-adapted in Salicornia europaea

Abstract

Abstract Halophytes have evolved unique strategies to cope with salinity. Salicornia europaea, a succulent euhalophyte plant, show optimal reproduction under 200 mM NaCl. However, the role of lipid metabolism caused by salinity in S. europaea is not fully understood. To gain insight into this, we conducted a combined lipidomic and transcriptomic analysis to investigate the molecular basis of lipid metabolism in response to 0 and 200 mM NaCl. GO and KEGG analysis revealed that salt treatment mainly affected glycosylphosphatidylinositol (GPI) anchored biosynthesis, secondary metabolite synthesis, plant hormone signal transduction, peroxisome, and glycosphingoipid biosynthesis. We identifited 485 lipid compounds, 27 of which showed altered abundances under salt treatment. Notably, lysophosphatidylcholine (LPC) and phytosphingosine-1-phosphate (S1P) significantly increased, while polyunsaturated monogalactosyldiacylglycerols (PA), lysophosphatidylinositol (LPI), phytoceramides with hydroxylated fatty acyl (PhytoCer-OHFA), phyto-glucosylceramide (Phyto-GluCer), sphingosine (Sph), and phytosphingosine (PhytoSph) markedly decreased. Additionally, the increase in DBI index was mostly phospholipids and sphingolipids, indicating that the lipid saturation was reduced, and the fluidity was higher, which may be related to the strong salt resistance of S. europaea. By comparing the average carbon chain length (ACL), it can be seen that the ACL coefficient of S1P is significantly reduced with 200 mM NaCl concentration, so we speculate that S1P may be related to the salt resistance.