| The traditional medicine Danshen (Salvia miltiorrhiza) belongs to the perennial herbaceous plants, classified as the Salivia, the dry root and rhizome are used for treating many diseases, such as the disease of heart head blood-vessel, it can remove stasis pain, invigorate the circulation of menstruation. Danshen contains various of active compounds, which are divided into two classes of tanshinone and phenolic acids, most of tanshinone compounds are a fat-soluble constituent of diterpene structure, more than 30 species have been identified. while another class phenolic acids are water-soluble, and of which there are more than 20 species of structures been characterized These compounds form the active components of Salvia miltiorrhiza, are the foundation of curing function. Plants generally have close symbiotic relationship with mycorrhiza, and mycorrhiza fungus form mutual symbiosis with plants which play an important role in the process of plant productivity and ecology system cycle producing carbon cycle. Arbuscular Mycorrhizal Fungi (AMF), an ancient and widely distributing fungiin nature, it infects plant roots, to improve absorbing water and mineral nutrition especial phosphorus by forming the symbioses, can keep the ecological balance, stability and improve the ecosystem sustainable productivity. During the mycorrhiza processing, plant will conduct a series of signal molecules reorganization, exchange, and transduction with arbuscular mycorrhizal fungi, plant will secrete plant hormone strigolactones to induct the branch of mycorrhizal accelerated, then fungi will secrete lipochitooligosaccharide applying to promote the formation of the mycorrhizal in the plants. Through the existing research of symbiosis model plants, we found that many plant genes, involved in the symbiosis formed process, participate in the process of signal transduction. 1. Salvia miltiorrhiza transcriptome and mycorrhizal signal pathway analysisWe profiled and compared S. miltiorrhiza root and leaf transcriptomes by Roche’s 454 GS-FLX pyrosequencing platform. Totally 64,139 unigenes were assembled, and 5,424 unigenes showed distinct transcript abundance between leaf and root. Our dataset for root and leaf of S. miltiorrhiza represents the major transcriptome changes and provides a valuable resource for further studies of the tissue-specific active pharmaceutical ingredient biosynthesis and regulation. 2. The relations between Phenolic acid synthesis and mycorrhizalSand with arbuscular mycorrhizal fungi is used to cultivate Salvia miltiorrhiza, dyed after six weeks and used microscope to observe the mycorrhizal morphology, the control group is significantly different from arbuscular mycorrhizal structure. We randomly selected three plants for biomass measuring, compared the dry weight and found that after mycorrhizal colonization the host plant obviously increased the growth and the biomass. High performance liquid chromatography (HPLC) was used to measure the secondary metabolites content in Salvia miltiorrhiza, such as caffeic acid, danshensu, rosmarinic acid and the contents were significantly increased. Additionally, the transcription of the genes, encoding the key enzymes involved in phenolic acids biosynthesis, such as PAL1, C4H,4CL2 and TAT, were determined by real-time PCR. As a result, the expression levels of the genes mentioned above were obviously up-regulated in the mycorrhizal infectiong group than that the control group. The transcription levels of RAM2 and DMI3 were also determined by real-time PCR, and the expression were improved involved in the convey pathway of mycorrhizal signal.When Salvia miltiorrhiza was infected by arbuscular mycorrhizal fungi, and established the symbiosis with arbuscular mycorrhizal, the study of the relationship between the related transcriptional expression levels of the genes and the secondary metabolites variation in content of phenolic acids, provided the reference to further study on phenolic acid biosynthesis and symbiosis. |
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