Endophytic Bacteria Promote The Signal Regulation Mechanism Of The Volatile Oil Accumulation Of The Medicinal Plant Atractylodes Lancea

Atractylodes lancea (Thunb.) DC., a member of the Compositae family, is a traditional Chinese medicinal plant. Volatile oils from A. lancea show antimicrobial activities as well. These oils comprise active secondary metabolites, including the characteristic components atractylone, ?-eudesmol, hinesol, and atractylodin.However, the natural resources of A. lancea were decreased due to increasingly serious environmental pollution. It's difficult to ensure the quality of the herbs cultivated away from their natural environment, production of secondary metabolites has been one of the most critical issues in industrial application of medical herbs.Recently, great attention has been paid to the effects of endophytes, on the accumulation of medicinal active ingredients. The promotion of endophytic fungus AL12 (Gilmaniella sp.) on volatile oil accumulation of A. lancea have been proved in our study group's previous work. How endophytic fungus induced the production of secondary metabolites in host plant, which signal molecules acted as the key role?What's the related regulation between those pathways? Investigation of the signaling transduction pathways related to secondary metabolite biosynthesis induced by endophytic fungus is helpful for elucidating the mechanism of plant secondary metabolite biosynthesis in endophytic fungus-host plant interaction. The results showed that, the main component from endophytic fugus which inducing secondary metabolite accumulation in A. lancea plantlets is exopolysaccharides (EPS).Meanwhile, fungal inoculation increased Jasmonic acid (JA) and salicylic acid (SA)generation and volatile oil accumulation, and these signal molecules interaction also take part in endophytic fugus-host symbiosis. The results showed that calcium(Ca2+)-calmodulin (CaM) induced by this endophyte mediates nitric oxide (NO)generation and brassinolide (BL) concentration, and also functions downstream of BL signalling, resulting in the up-regulation of volatile oil accumulation in A. lancea plantlets. All these signal molecules play key roles in the interaction of endophytic fugus and host plant. As responses of plant to microbe infection, each signal molecule(pathways) are represent unique regulation or metabolite processes. Base on the results, the technology platform of A. lancea plantlets proteomics was established to further study the endophytic fugus-host symbiosis.