| As a traditional Chinese herb medicine,Ophiocordyceps sinensis has received extensive attention and ongoing research around the world.However,the metabolomic differences between different parts of O.sinensis have not been reported yet.In this study,metabolomic method based on HPLC-ESI-TOF/MS was used to investigated the metabolomic variation between different parts of O.sinensis at different developmental stages i.e.head and tail of insect cadaver,head,tail and fruiting body of insect cadaver with 1 cm strooma,head,tail and fruiting body of insect cadaver with 2-3 cm stroma,head,tail and fruiting body of insect cadaver with 3-5 cm stroma,head,tail and fruiting body of insect cadaver with mature stroma.Meanwhile,the effect of one of the differential metabolites,phytosphingosine,on the growth and development of Hirsutella sinensis was explored.The results will provide a theoretical basis for the artificial cultivation and rational utilization of O.sinensis.The results of principal component analysis(PCA)of metabolites from O.sinensis show that there are significant differences between metabolites in different parts of O.sinensis at the same stage.According to the score plots of partial least squares discrimination analysis(PLS-DA),we could find that as the O.sinensis matures gradually,the difference between the fruiting body and the head decreases gradually.Subsequently,significant differential compounds from the different parts were identified in conjunction with t-test,and the identified metabolites were clustered by using Hierarchical Clustering Analysis(HCA).The results show that:at the stage of zombie the worm head contained the most matabolites of all the head parts;meanwhile,the fruiting body of the growing stage(length of the fruiting bodies are 1 cm or 2-3 cm)contained the most metabolites of all the samples.Obviously,the zombie head and the fruiting bodies of the growing stage have better utilization value.The popularly used O.sinensis are the cordyceps with 3-5 cm fruiting bodies,which have immature stroma and significantly decreased metabolites.From the view of metabolites utilization the cordyceps with 3-5 cm fruiting bodies have less value than the cordyceps with 1 cm or 2-3 cm fruiting bodies.Phytosphingosine is one of the most important differential markers of the different parts of O.sinensis.From the accumulating characteristic of phytosphingosine in the head part of the zombie and distribution characteristics of phytosphingosine in different parts of O.sinensis at different developmental stages,we found that it may play an important role in metabolism regulation and fruiting body formation.Results of experiment indicate that phytosphingosine had a significant effect on the metabolism of H.sinensis.Metabolic pathway analysis shows obvious change in purine metabolism,pyrimidine metabolism,phenylalanine metabolism,malate-asparate shutlle,sphingolipid metabolism and glycerophospholipid metabolism in the mycelium of H.sinensis.The increased ability of energy and lipds metabolism has great significance for the growth of wild Cordyceps sinensis for that it can make the fungus obtain energy and nutuents from the fatty Hepiaua larva for growth in the high-cold environment. |
