An endophyte of Picrorhiza kurroa Royle ex. Benth, producing menthol, phenylethyl alcohol and 3-hydroxypropionic acid, and other volatile organic compounds

Abstract

An endophytic fungus, PR4 was found in nature associated with the rhizome of Picrorhiza kurroa, a high altitude medicinal plant of Kashmir Himalayas. The fungus was found to inhibit the growth of several phyto-pathogens by virtue of its volatile organic compounds (VOCs). Molecular phylogeny, based on its ITS1-5.8S-ITS2 ribosomal gene sequence, revealed the identity of the fungus as Phomopsis/Diaporthe sp. This endophyte was found to produce a unique array of VOCs, particularly, menthol, phenylethyl alcohol, (+)-isomenthol, β-phellandrene, β-bisabolene, limonene, 3-pentanone and 1-pentanol. The purification of compounds from the culture broth of PR4 led to the isolation of 3-hydroxypropionic acid (3-HPA) as a major metabolite. This is the first report of a fungal culture producing a combination of biologically and industrially important metabolites—menthol, phenylethyl alcohol, and 3-HPA. The investigation into the monoterpene biosynthetic pathway of PR4 led to the partial characterization of isopiperitenone reductase (ipr) gene, which seems to be significantly distinct from the plant homologue. The biosynthesis of plant-like-metabolites, such as menthol, is of significant academic and industrial significance. This study indicates that PR4 is a potential candidate for upscaling of menthol, phenylethyl alcohol, and 3-HPA, as well as for understanding the menthol/monoterpene biosynthetic pathway in fungi.

An Endophytic Diaporthe apiculatum Produces Monoterpenes with Inhibitory Activity against Phytopathogenic Fungi

“…This investigation showed that VOCs produced by the endophytic D apiculatum FPYF 3052 were able to inhibit the growth of fungal pathogens (Table 2). This result was consistent with evidence on the VOCs of some endophytic fungi of Diaporthe previously reported [7,14,15,17]. These fungi were recorded as Diaporthe sp.…”

“…The VOCs of Diaporthe sp. PR4 exhibited the greatest inhibition rate on Rhizoctonia solani by 100% after 24 hours [14]. The VOCs of Diaporthe sp.…”

“…These fungi were recorded as Diaporthe sp. PR4 from the rhizome of Picrorhiza kurroa [14], Diaporthe sp. EC-4 from Odontoglossum sp.…”

“…The VOCs are also being examined as to their roles in the defense and inhibitive effects against pathogens and insects in plants [6,7]. Those endophytic strains of Diaporthe genus isolated from some plants or trees, such as Picrorhiza kurro [14], Odontoglossum sp. [15], and Catharanthus roseus [7,16], are able to produce a unique mixture of inhibitive bioactive VOCs against many important fungal pathogens associated with crops and trees.…”

Variation of floral volatiles and fragrance reveals the phylogenetic relationship among nine wild tree peony species

“…In the previous research, geraniol has been detected as an important component in the aroma matrix of orthodox tea . Except that, citronellol and phenylethyl alcohol could also be used to enhance the fragrance and produce perfumes, and citronellol was detected as the main fragrance compound of rose scent from tree peony cultivars . On the contrary, there was a negative correlation between sweet attribute and benzaldehyde (−0.681), caused by bitter and almond scents of benzaldehyde .…”