RESUMO
Two homogeneous polysaccharides, GEP-3 and GEP-4, were purified from Gastrodia elata, a precious traditional Chinese medicine. Their structural characteristics were obtained using HPGPC, PMP-HPLC, LC/MS, FT-IR, NMR, and SEM methods. GEP-3 was 1,4-glucan with molecular weight of 20 kDa. Interestingly, GEP-4 comprised of a backbone of â[4)-α-Glcp-(1]10â[4)-α-Glcp-(1â]5[6)-ß-Glcp-(1]11â6)-α-Glcp-(3â and two branches of ß-Glcp and p-hydroxybenzyl alcohol citrate, with repeating p-hydroxybenzyl alcohol attached to the backbone chain at O-6 position of â4,6)-α-Glcp-(1â and O-1 position of â3,6)-α-Glcp-(1â. GEP-4 is a novel polysaccharide obtained and characterized for the first time. Bioactivity test indicated that both of them significantly promote the growth of Akkermansia muciniphila (Akk. muciniphila). Furthermore, GEP-3 and GEP-4 promoted the growth of Akk. muciniphila from high-fat diet (HFD) fecal microbiota. These results indicated that GEP-3 and GEP-4 were potential Akk. muciniphila growth promoters.
Assuntos
Gastrodia , Extratos Vegetais/farmacologia , Polissacarídeos/farmacologia , Akkermansia/efeitos dos fármacos , Akkermansia/crescimento & desenvolvimento , Akkermansia/isolamento & purificação , Animais , Dieta Hiperlipídica , Modelos Animais de Doenças , Fezes/microbiologia , Gastrodia/química , Microbioma Gastrointestinal , Camundongos , Estrutura Molecular , Hepatopatia Gordurosa não Alcoólica/microbiologia , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Polissacarídeos/química , Polissacarídeos/isolamento & purificaçãoRESUMO
Armillaria species (Basidiomycota, Physalacriaceae) are well known as plant pathogens related to serious root rot disease on various trees in forests and plantations. Interestingly, some Armillaria species are essential symbionts of the rare Chinese medicinal herb Gastrodia elata, a rootless and leafless orchid used for over 2000 years. In this work, an 87.3-M draft genome of Armillaria gallica 012m strain, which was symbiotic with G. elata, was assembled. The genome includes approximately 23.6% repetitive sequences and encodes 26,261 predicted genes. In comparison with other four genomes of Armillaria, the following gene families related to pathogenicity/saprophytic phase, including cytochrome P450 monooxygenases, carbohydrate-active enzyme AA3, and hydrophobins, were significantly contracted in A. gallica 012m. These characteristics may be beneficial for G. elata to get less injuries. The genome-guided analysis of differential expression between rhizomorph (RH) and vegetative mycelium (VM) showed that a total of 2549 genes were differentially expressed, including 632 downregulated genes and 1917 upregulated genes. In the RH, most differentially expressed genes (DEGs) related to pathogenicity were significantly upregulated. To further elucidate gene function, Gene Ontology enrichment analysis showed that the upregulated DEGs significantly grouped into monooxygenase activity, hydrolase activity, glucosidase activity, extracellular region, fungal cell wall, response to xenobiotic stimulus, response to toxic substance, etc. These phenomena indicate that RH had better infection ability than VM. The infection ability of RH may be beneficial for G. elata to obtain nutrition, because the rhizomorph constantly infected the nutritional stems of G. elata and formed the hyphae that can be digested by G. elata. These results clarified the characteristics of A. gallica 012m and the reason why the strain 012m can establish a symbiotic relationship with G. elata in some extent from the perspective of genomics.