A community of unknown, endophytic fungi in western white pine

Abstract

The endophytic fungi of woody plants may be diverse as often claimed, and likewise, they may be functionally novel as demonstrated in a few studies. However, the endophyte taxa that are most frequently reported tend to belong to fungal groups composed of morphologically similar endophytes and parasites. Thus, it is plausible that endophytes are known (i.e., described) parasites in a latent phase within the host. If this null hypothesis were true, endophytes would represent neither additional fungal diversity distinct from parasite diversity nor a symbiont community likely to be novel ecologically. To be synonymous with parasites of the host, endophytes should at least be most closely related to those same parasites. Here we report that seven distinct parasites of Pinus monticola do not occur as endophytes. The majority of endophytes of P. monticola (90% of 2,019 cultures) belonged to one fungal family, the Rhytismataceae. However, not a single rhytismataceous endophyte was found to be most closely related by sequence homology to the three known rhytismataceous parasites of P. monticola. Similarly, neither endophytic Mycosphaerella nor endophytic Rhizosphaera isolates were most closely related to known parasites of P. monticola. Morphologically, the endophytes of P. monticola can be confounded with the parasites of the same host. However, they are actually most closely related to, but distinct from, parasites of other species of Pinus. If endophytes are generally unknown species, then estimates of 1 million endophytes (i.e., approximately 1 in 14 of all species of life) seem reasonable.

Leaf endophytes and Populus genotype affect severity of damage from the necrotrophic leaf pathogen, Drepanopeziza populi

“…While the total number of fungal leaf endophyte species globally is unknown, some estimates suggest that they could represent as many as 1 out of every 14 species of life on Earth (Ganley et al 2004). They occur in all lineages of land plants (Stone et al 2000), and reach impressive levels of species diversity within individual plants (Arnold et al 2002).…”

Cultural Endophytic Fungi Associated with <i>Dendrobium Officinale</i>:Identification, Diversity Estimation and their Antimicrobial Potential

“…It is estimated that the global endophytic fungi account for at least 1 million fungal species in nature 4 , whereas only a small fraction of microorganisms has been identified. The great biodiversity and abundance of fungal endophytes occurring in plant tissues demonstrate their functional diversity and ecological importance for the hosts 5,6 .…”

PCR-Mediated Detection of Endophytic and Phytopathogenic Fungi from Needles of the Japanese Black Pine, &lt;i&gt;Pinus thunbergii&lt;/i&gt;

“…were observed to have pathogenicity on healthy Japanese black pine needles (Suto & Ougi, 1998;Seo et al, 2012;Yamamoto et al, 1964). On the other hand, these fungi have been reported to be endophytic fungi of conifers, including the Japanese black pine (Yoo & Eom, 2012;Qadri et al, 2014;Ganley et al, 2004;Ganley & Newcombe, 2006). Thus, these fungi, which are considered to be phytopathogenic fungi, can be considered endophytic fungi of Japanese black pine needles in the initial stage after infection and cause disease with some typical symptoms and reproductive structures such as stromata in the latter stages.…”