Fungal community on decomposing leaf litter undergoes rapid successional changes
Fungal community on decomposing leaf litter undergoes rapid successional changes
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DOI：
10.1038/ismej.2012.116
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发表时间：
2013-03-01
期刊：
影响因子：
11
通讯作者：
Baldrian, Petr
中科院分区：
文献类型：
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作者：
Voriskova, Jana;Baldrian, Petr
真菌被认为是陆地生态系统中死亡植物生物量的主要分解者。然而，目前关于凋落物分解过程中真菌群落连续变化的知识是有限的。在这里，我们利用真菌内转录间隔区 (ITS) 区域和纤维二糖水解酶 I (cbhI) 基因的 454 焦磷酸测序，探索了在以栎树为主的温带森林中，经过 24 个月的凋落物分解过程中真菌群落的发展，纤维二糖水解酶 I (cbhI) 基因编码外切纤维素酶，专门针对纤维素分解者。为了量化叶际真菌在凋落物分解中的参与，还分析了活叶和即将脱落前的叶子中的真菌群落。结果表明，真菌快速演替，真菌群落的组成发生巨大变化。此外，大多数丰富的类群只是暂时在基质中占主导地位。真菌多样性在叶子衰老时最低，直到第 4 个月才增加，并且在随后的分解过程中没有显着变化。高度多样化的叶际真菌群落在脱落前 2 个月栖息在活橡树叶中，并且这些叶际类群在早期分解期间直至第四个月期间构成了真菌群落的很大一部分。分配给子囊菌门的序列在活叶中和分解的早期阶段显示出最高的相对丰度。相比之下，属于担子菌门、特别是担子菌酵母的序列的相对丰度随着时间的推移而增加。尽管在所有分解阶段，垫料中都含有纤维素，但纤维素分解真菌的群落随着时间的推移发生了很大的变化。结果表明，凋落物分解是一个由各种真菌类群介导的高度复杂的过程。 ISME 期刊 (2013) 7, 477-486； doi：10.1038/ismej.2012.116； 2012 年 10 月 11 日在线发布
Fungi are considered the primary decomposers of dead plant biomass in terrestrial ecosystems. However, current knowledge regarding the successive changes in fungal communities during litter decomposition is limited. Here we explored the development of the fungal community over 24 months of litter decomposition in a temperate forest with dominant Quercus petraea using 454-pyrosequencing of the fungal internal transcribed spacer (ITS) region and cellobiohydrolase I (cbhI) genes, which encode exocellulases, to specifically address cellulose decomposers. To quantify the involvement of phyllosphere fungi in litter decomposition, the fungal communities in live leaves and leaves immediately before abscission were also analysed. The results showed rapid succession of fungi with dramatic changes in the composition of the fungal community. Furthermore, most of the abundant taxa only temporarily dominated in the substrate. Fungal diversity was lowest at leaf senescence, increased until month 4 and did not significantly change during subsequent decomposition. Highly diverse community of phyllosphere fungi inhabits live oak leaves 2 months before abscission, and these phyllosphere taxa comprise a significant share of the fungal community during early decomposition up to the fourth month. Sequences assigned to the Ascomycota showed highest relative abundances in live leaves and during the early stages of decomposition. In contrast, the relative abundance of sequences assigned to the Basidiomycota phylum, particularly basidiomycetous yeasts, increased with time. Although cellulose was available in the litter during all stages of decomposition, the community of cellulolytic fungi changed substantially over time. The results indicate that litter decomposition is a highly complex process mediated by various fungal taxa. The ISME Journal (2013) 7, 477-486; doi:10.1038/ismej.2012.116; published online 11 October 2012