Department of Ecology and Evolutionary Biology, 1200 Sunnyside Ave., University of Kansas, Lawrence, Kansas 66045.
Mycologia. 2004 Sep-Oct;96(5):955-9.
Fungi in the genus Escovopsis are known only from the fungus gardens of attine ants. Previous work has established that these anamorphic fungi, allied with the Hypocreales, are specialized and potentially virulent parasites of the ancient mutualism between attine ants and their fungal cultivars. It is unclear whether the primary nutrient source for the pathogen is the mutualist fungal cultivar or the vegetative substrate placed on the gardens by the ants. Here, we determine whether Escovopsis weberi is a parasite of the fungal cultivar, a competitor for the leaf substrate, or both. Bioassays reveal that E. weberi exhibits rapid growth on pure cultivar and negligible growth on sterilized leaf fragments. Light microscopy examination of hyphalhyphal interactions between E. weberi and the ant fungal cultivar indicate that E. weberi, unlike invasive necrotrophs that always penetrate host hyphae, can secrete compounds that break down host mycelium before contact occurs. Thus, E. weberi is a necrotrophic parasite of the fungal cultivar of attine ants.
仅在菌蚁的真菌园里发现了 Escovopsis 属真菌。先前的研究表明，这些与 Hypocreales 相关的无性型真菌是菌蚁与其真菌培养物之间古老共生关系的专门化和潜在的致病寄生虫。尚不清楚病原体的主要营养来源是共生真菌培养物还是蚂蚁放在花园上的营养基质。在这里，我们确定 Escovopsis weberi 是真菌培养物的寄生虫、叶基质的竞争者，还是两者兼而有之。生物测定表明，E. weberi 在纯培养物上生长迅速，在消毒的叶片碎片上生长微不足道。E. weberi 与蚂蚁真菌培养物之间菌丝-菌丝相互作用的光学显微镜检查表明，E. weberi 可以分泌化合物，在接触发生之前分解宿主菌丝，而不像总是穿透宿主菌丝的侵袭性坏死营养物那样。因此，E. weberi 是菌蚁真菌培养物的一种坏死寄生虫。
