Chemical interactions between two lichen-degrading fungi
Chemical interactions between two lichen-degrading fungi
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DOI：
10.1023/a:1005540622612
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发表时间：
2000-08-01
影响因子：
2.3
通讯作者：
Lawrey, JD
中科院分区：
文献类型：
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作者：
Lawrey, JD
许多地衣专性真菌病原体，即所谓的地衣真菌，似乎对抗生素地衣次生代谢物具有耐受性。然而，已知某些地衣真菌会受到地衣化学防御的强烈抑制，甚至是那些在自然界中经常发现地衣的真菌。其中一种真菌是 Nectria parmeliae，这是一种专性地衣真菌，在许多地衣物种中都可以观察到。在弗吉尼亚州北部对这种真菌的实地观察表明，人们对地衣 Punctelia rudecta 有着明显的偏爱。实验室研究表明，帕美利亚猪笼草无法在这种地衣组织上生长，除非首先用丙酮清洗以去除酚类防御化合物。在另一种地衣居民（一种镰刀菌）酶降解 P. rudecta 的主要地衣化合物 Lecanoric Acid (LEC) 后，确定 N. parmeliae 可以在自然界中的 P. rudecta 上生长。弗吉尼亚州北部的实地研究表明，观察到的含有 N. parmeliae 的地衣通常也含有镰孢菌。此外，高效液相色谱 (HPLC) 显示 LEC 在 90 天内被镰孢菌完全降解，从而允许帕美利亚猪笼草生长。总而言之，这些结果表明，一些专性地衣真菌不能在某些地衣上定殖，除非事先对这些地衣进行了化学处理。
Many obligate fungal pathogens of lichens, the so-called lichenicolous fungi, seem to be tolerant of antibiotic lichen secondary metabolites. However, certain lichenicolous fungi are known to be strongly inhibited by chemical defenses of lichens, even those on which they are frequently found in nature. One of these fungi is Nectria parmeliae, an obligate lichenicolous fungus that is observed on many species of lichens. Field observations of this fungus in northern Virginia indicate a marked preference for the lichen Punctelia rudecta. Laboratory studies established that N. parmeliae is incapable of growing on tissues of this lichen unless they are first washed with acetone to remove phenolic defense compounds. It was determined that N. parmeliae can grow on P. rudecta in nature after another lichen inhabitant, a species of Fusarium, enzymatically degrades lecanoric acid (LEC), the dominant lichen compound of P. rudecta. Field studies in northern Virginia demonstrate that observed lichens harboring N. parmeliae generally also harbor the Fusarium sp. Furthermore, high performance liquid chromatography (HPLC) shows that LEC is completely degraded by Fusarium in 90 days, which permits growth of N. parmeliae. Taken together, these results suggest that some obligate lichenicolous fungi cannot colonize certain lichens unless there has been prior chemical processing of these lichens.