Overexpression of from Promotes Suberin Monomers' Production and Salt Tolerance in .

Very-long-chain fatty acids (VLCFAs) are precursors for the synthesis of various lipids, such as triacylglycerols, sphingolipids, cuticular waxes, and suberin monomers, which play important roles in plant growth and stress responses. However, the underlying molecular mechanism regulating VLCFAs' biosynthesis in quinoa ( Willd.) remains unclear. In this study, we identified and functionally characterized putative 3-ketoacyl-CoA synthases (KCSs) from quinoa. Among these genes, showed high transcript levels in the root tissues and these were rapidly induced by salt stress. was localized to the endoplasmic reticulum. Overexpression of in Arabidopsis resulted in significantly longer primary roots and more lateral roots. Ectopic expression of in promoted the accumulation of suberin monomers. The occurrence of VLCFAs with C22-C24 chain lengths in the overexpression lines suggested that plays an important role in the elongation of VLCFAs from C20 to C24. The transgenic lines of overexpressed showed increased salt tolerance, as indicated by an increased germination rate and improved plant growth and survival under salt stress. These findings highlight the significant role of in VLCFAs' production, thereby regulating suberin biosynthesis and responses to salt stress. could be utilized as a candidate gene locus to breed superior, stress-tolerant quinoa cultivars.