Pestalotiopsis guepinii, a Taxol-producing Endophyte of the Wollemi Pine, Wollemia nobilis

Abstract

Wollemia nobilis (Wollemi pine), an araucariaceous plant, whose closest known relatives are from the Jurassic period, occurs in the Wollemi National Park near Sydney, Australia. This tree is host to many endophytic fungi, including Pestalotiopsis guepinii which produces taxol, an important anticancer drug. It was shown by immunological, spectroscopic and chromatographic means to be identical with authentic taxol obtained from Taxus brevifolia (Pacific yew). Since the Wollemi pine does not produce taxol, how might a taxol-producing fungus be present in this unusual tree? Spores of P. guepinii possess several appendages which strongly interact with hydrophobic surfaces including plastics and the pinnae of birds’ feathers. Scanning electron microscopy of the conidia of P. guepinii clearly shows the spores on the feathers of a green-checked conure and a cockatiel. Conceivably, the fungus may have acquired the ability to produce taxol from a foreign or local yew and then is carried to the Wollemi pine site by native birds.

Screening the endophytic flora ofWollemia nobilisfor alternative paclitaxel sources

“…While our study failed to re-establish the previously reported endophytic paclitaxel producer, Pestalotiopsis guepini harbored by Wollemia nobilis in its natural habitat (Strobel et al 1997), it recovered interesting isolates bearing indications of presumed taxane biosynthesis, be it on a metabolic (Phomopsis sp. & Cladosporium langeronii) or on a genomic level (C. langeronii).…”

“…Strains #1, 3 and 4 were isolated from the surfacetreated (70% ethanol for 10 min) Wollemi pine needles by hyphal tip transfer method (Strobel et al 1997). Strain #2 was isolated from the surface-treated (70% ethanol for 10 sec, 15% NaOCl:H 2 O, 1:1 for 3 min, 3 )sterile water for 2 min) needles while attempting to generate plant callus cultures on B5 medium (Gamborg et al 1968) containing 0.5 mg/l 2,4-dichlorophenoxyacetic acid under a day/night regime (16/8 h; 2500 lux) (van Uden et al 1990).…”

“…This relictual pine was found to harbor a paclitaxel-producing endophyte Pestalotiopsis guepini (Strobel et al 1997). Thanks to the unprecedented conservation programme undertaken by the Australian government (NSW Department of Environment and Conservation 2006) making Wollemi pine commercially available as a potted plant, the great opportunity of studying this extraordinary conifer worldwide is now at hand.…”

Current Understanding of Endophytes: Their Relevance, Importance, and Industrial Potentials

“…Stierle et al (1993) 31 was the first to isolate endophytic fungi (Taxomyces anderanae) from a medicinal plant (Taxus brevifolia) [16]. Huang et al (2007) 4 also got a total 42 endophytic fungi strain from Nerium oleander L. Endophytic fungi also exist in the marine plants [33]. The endophytic and obligate marine fungus Ascochyta salicorniae was reported in green algae [32].…”

“…Endophytic fungi also are adopted widely for their application in promoting plant growth and protecting the plant to reduce diseases and insect pests. Strobel et al (1997) 33 reported that a few species of endophytic fungi have been identified as sources of anticancer, anti-diabetic, insecticidal and immunosuppressive compounds. Endophytic fungi may also produce metabolites with thermo protective role.…”