Differential metabolic analysis of Bletilla striata and its mutants based on widely targeted metabolomics and transcriptomics

Abstract

The pseudobulb of Bletilla striata (Thunb. ex A. Murray) is traditionally used to treat hemostasis, skin regeneration, and canker bleed treatment and reducing inflammation in China. A wild albino variety of B. striata has been discovered, which differs from the regular purplish red or pink species. To investigate the differences in metabolites between the two groups, the flowers and pseudobulbs of normal B. striata (BSNF, BSNP) and mutant B. striata (BSMF, BSMP) were analyzed using a combination of widely targeted metabolomics and transcriptomics. The results showed that the two varieties had different metabolites. Quinone of 4,8-dihydroxy naphthol-1-O-glucoside, a special substance, was significantly higher in BSMP than in BSNP. Furthermore, BSNP showed higher levels of medicinal substances, such as fumaric acid, rheic acid, and 2,3-dihydroxybenzoic acid which possess antibacterial and anti-inflammatory properties. The Kyoto Encyclopedia of Genes and Genomes analysis revealed that the differential metabolisms of the two varieties were clustered in fructose and mannose metabolisms and amino acid biosynthesis. Sucrose-6-phosphate, the key metabolite in the polysaccharide biosynthesis pathway, was significantly upregulated in BSNP vs. BSMP. The quantitative analysis revealed that total polysaccharides, glucose, and mannose contents were significantly higher in BSMP than in BSNP, suggesting that BSMP efficiently regulate the accumulation of key metabolites in the polysaccharide biosynthesis pathway by regulating important genes, which efficiently stimulated polysaccharide formation. This study provides new insights into B. striata and the phytochemical pathways of its mutants, and their unique substances can be used in the development of functional medicines and industrial supplies that are tailored to specific needs.