School of Life Sciences, University of KwaZulu Natal, PBag X01, Scottsville 3209, South Africa.
Fungal Biol. 2013 Jun;117(6):431-8. doi: 10.1016/j.funbio.2013.04.007. Epub 2013 May 9.
Lichens are symbiotic associations of a fungus (usually an Ascomycete) with green algae and/or a cyanobacterium. They dominate on 8 % of the world's land surface, mainly in Arctic and Antarctic regions, tundra, high mountain elevations and as components of dryland crusts. In many ecosystems, lichens are the pioneers on the bare rock or soil following disturbance, presumably because of their tolerance to desiccation and high temperature. Lichens have long been recognized as agents of mineral weathering and fine-earth stabilization. Being dominant biomass producers in extreme environments they contribute to primary accumulation of soil organic matter. However, biochemical role of lichens in soil processes is unknown. Our recent research has demonstrated that Peltigeralean lichens contain redox enzymes which in free-living fungi participate in lignocellulose degradation and humification. Thus lichen enzymes may catalyse formation and degradation of soil organic matter, particularly in high-stress communities dominated by lower plants. In the present review we synthesize recently published data on lichen phenol oxidases, peroxidases, and cellulases and discuss their possible roles in lichen physiology and soil organic matter transformations.
地衣是真菌（通常为子囊菌）与绿藻和/或蓝细菌共生的联合体。它们主要分布在世界陆地表面的 8%，主要分布在北极和南极地区、冻原、高山地区以及旱地外壳的组成部分。在许多生态系统中，地衣是在受到干扰后裸岩或土壤上的先驱者，这可能是因为它们耐受干燥和高温。地衣长期以来被认为是矿物风化和细土稳定的因素。作为极端环境中的主要生物量生产者，它们有助于土壤有机质的初次积累。然而，地衣在土壤过程中的生化作用尚不清楚。我们最近的研究表明，皮壳衣科地衣含有氧化还原酶，这些酶在自由生活的真菌中参与木质纤维素的降解和腐殖质的形成。因此，地衣酶可能催化土壤有机质的形成和降解，特别是在以低等植物为主的高压力群落中。在本综述中，我们综合了最近发表的关于地衣酚氧化酶、过氧化物酶和纤维素酶的数据，并讨论了它们在地衣生理学和土壤有机质转化中的可能作用。
