Roles of endophytic fungi in medicinal plant abiotic stress response and TCM quality development

Perspective and challenges of mycorrhizal symbiosis in orchid medicinal plants

The family Orchidaceae is of the most diverse taxon in the plant kingdom, and most of its members are highly valuable herbal medicines. Orchids have a unique mycorrhizal symbiotic relationship with specific fungi for carbohydrate and nutrient supplies in their whole lifecycle. The large-scale cultivation of the medicinal plant Gastodia elata is a successful example of using mycorrhizal symbiotic technology. In this review, we adopted G. elata and Dendrobium officinale as examples to describe the characteristics of orchid mycorrhiza and mycorrhizal benefits for host plants' growth and health (e.g. biotic and abiotic stress and secondary metabolite accumulation). The challenges in applying mycorrhizal technology to the cultivation of orchid medicinal plants in the future were also discussed. This review aims to serve as a theoretical guide for the cultivation of mycorrhizal technology in medicinal orchid plants.

Diverse biological activities and secondary metabolites profile of Penicillium brevicompactum HE19ct isolated from the high-Andean medicinal plant Perezia coerulescens

Endophytic fungi produced attractive primary and secondary metabolites for industries, pharmacology, and biotechnology. The bioactive potential of HE19ct, identified as Penicillium brevicompactum according to ITS-BenA-caM, was addressed. Antimicrobial and antioxidant activities and secondary metabolite contents using four culture media in Agar-plate (ApF) and Submerged (SmF) fermentation were evaluated. Some plant growth-promoting (PGP) traits and their related genes were tested. HE19ct exhibited antimicrobial activity against Staphylococcus aureus, Enterococcus faecalis, Candida albicans, C. tropicalis, Fusarium sp., Geotrichum candidum, and Alternaria sp. All cultures showed DPPH scavenging activity and phenolic compounds, where ethyl acetate extract of SmF with malt extract showed higher activity and SmF/ApF with potato-dextrose exhibited higher yield, respectively. HE19ct solubilized tricalcium-phosphate and produced siderophore, endoglucanase, proteinase, and amylase. It enhanced the alfalfa's germination at 15 °C, root development, and phenols production at 15 and 24 °C. Phenols, tannins, anthraquinones, triterpenoids/steroids, and alkaloids production were detected depending on culture media. Polyketide synthase type I gene (PksI), subtilisin-like protease prb 1 (Pbr), and siderophore D (sidD) were PCR-amplified. Finally, HE19CT could be a promising source of interesting bioactive compounds for pharmacology and agriculture mainly in extreme conditions, then metabolomic and functional genetic research must be performed to support their appropriate application.