A community of unknown, endophytic fungi in western white pine
A community of unknown, endophytic fungi in western white pine
复制标题
DOI：
10.1073/pnas.0401513101
复制
发表时间：
2004-07-06
影响因子：
11.1
通讯作者：
Newcombe, G
中科院分区：
文献类型：
--
作者：
Ganley, RJ;Brunsfeld, SJ;Newcombe, G
正如人们经常声称的那样，木本植物的内生真菌可能是多种多样的，同样，正如一些研究所证明的那样，它们在功能上可能是新颖的。然而，最常报道的内生菌类群往往属于由形态相似的内生菌和寄生虫组成的真菌类群。因此，内生菌可能是宿主体内潜伏期的已知（即描述的）寄生虫。如果这个零假设成立，那么内生菌既不代表与寄生虫多样性不同的额外真菌多样性，也不代表生态上可能新颖的共生群落。为了与宿主的寄生虫同义，内生菌至少应该与那些相同的寄生虫最密切相关。在这里，我们报告了七种不同的山松寄生虫并不作为内生菌出现。 P. monticola 的大多数内生菌（2,019 个培养物中的 90%）属于真菌科 Rhytismataceae。然而，没有发现任何一种纹状内生菌与 P. monticola 的三种已知纹状体寄生虫在序列同源性上最密切相关。同样，内生分枝球菌和内生根球菌分离株均与已知的 P. monticola 寄生虫关系最密切。在形态学上，A monticola 的内生菌可能与同一宿主的寄生虫混淆。然而，它们实际上与其他松属物种的寄生虫关系最密切，但又有所不同。如果内生菌通常是未知物种，那么估计 100 万内生菌（即约占所有生命物种的四分之一）似乎是合理的。
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 A 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.