Fig. 4

Quinoa seed germination was accompanied by remodeling and modification of cell wall. A Heatmap analysis of DEGs involved in cell wall remodeling and modification process during quinoa seed germination. α-fucosidase and β-galactosidase are important enzymes in xyloglucans degradation, and enzymes like PME, PMEI and PEL are involved in pectin degradation. Genes encoding xyloglucan hydrolase, xyloglucan endotransglycosylase, and xyloglucan:xyloglucosyl transferase are associated with cellular xyloglucan metabolic process, catalyzing the remodeling and mobilization of xyloglucan chains. UDP-glycosyltransferases, catalyzed the formation of glycosidic bonds by using nucleotide sugars as monosaccharide donor, promoting the synthesis of cell wall polysaccharides. The genes associated in above processes are significantly up-regulated after seed imbibition. B The transcript levels of four genes involved in cell-wall remodeling, CqPMEI, CqXTH8, CqXTH23 and CqUGT85A2, were detected by qRT-PCR assay, which were upregulated at imbibed stage during germination. Values are means ± SD (n = 3). *** P < 0.001, Student's t-test. C Dynamic changes of some metabolites involved in cell wall synthesis and degradation, including fucose, galactose, and xylose. Values are means of three independent experiments ± SD, indicated the relative content of target metabolites based on the peak area