Structural and functional variation in soil fungal communities associated with litter bags containing maize leaf

Abstract

Soil fungi are key players in the degradation of recalcitrant organic matter in terrestrial ecosystems. To examine the organisms and genes responsible for complex organic matter degradation in soil, we tracked changes in fungal community composition and expressed genes in soil adjacent to mesh bags containing maize leaves undergoing decomposition. Using high-throughput sequencing approaches, changes in fungal community composition were determined by targeting 18S rRNA gene sequences, whereas community gene expression was examined via a metatranscriptomic approach. The majority of the 93 000 partial 18S rRNA gene sequences generated, were affiliated with the Ascomycota and Basidiomycota. Fungal diversity was at least 224 operational taxonomic units at the 97% similarity cutoff level. During litter degradation, the relative proportion of Basidiomycota increased, with a decrease in Ascomycota : Basidiomycota ratios over time. The most commonly detected decomposition-associated fungi included Agaricomycetes and Tremellales as well as unclassified Mucoromycotina. The majority of protein families found in the metatranscriptomic data were affiliated to fungal groups described to degrade plant-derived cellulose, such as Mucoraceae, Chaetomiaceae, Sordariaceae, Sebacinaceae, Tremellaceae, Psathyrellaceae and Schizophyllaceae. The combination of high-throughput rRNA gene-based and metatranscriptomic approaches provided perspectives into the organisms and genes involved in complex organic matter in soil.

Land-use intensity and soil properties shape the composition of fungal communities in Mediterranean peaty soils drained for agricultural purposes

“…Our results are consistent with the description of lower abundance of Chytridiomycota by Lienhard et al (2014) under no-till system as compared to conventional tillage, according to the ability of this phylum to have resistant structures that permit survival through periodic drying and high summer temperatures typically occurring under tilled soils (Gleason et al 2004). Similarly, Artz et al (2007) detected no Chytridiomycota sequences in peatlands abandoned for more than 5 years, whereas Kuramae et al (2013) observed Chytridiomycota in buried maize leaves. Therefore, our data support the hypothesis that this phylum contributes to the decomposition of crop residues with a high C:N ratio.…”

“…For this reason, the SSU rRNA region is considered more suitable for comparing and for discerning the highest fungal phylogenetic ranks (i.e., phyla and orders), and therefore, it is useful for an initial assessment of the total soil fungal community (Hunt et al 2004) also when using the most recent high-throughput sequencing techniques (Kuramae et al 2013;Lienhard et al 2014). Moreover, the SSU rRNA region is known to be a successful marker for Chytridiomycota identification (Freeman et al 2009), and it generally has a higher discriminatory power for basal fungi (including Zygomycota) compared to both the ITS region and the nuclear ribosomal large subunit (LSU; Schoch et al 2012).…”

“…Moreover, the SSU rRNA region is known to be a successful marker for Chytridiomycota identification (Freeman et al 2009), and it generally has a higher discriminatory power for basal fungi (including Zygomycota) compared to both the ITS region and the nuclear ribosomal large subunit (LSU; Schoch et al 2012). Finally, another reason to target the SSU rRNA region is the availability of the SILVA database, which is a well-curated, and annotated database for such a gene (Kuramae et al 2013).…”

“…Corticiales are usually observed in forest soils as decomposers of dead woody substrates (i.e., saprotrophs; Allison et al 2007). The mycoparasites Tremellales were mostly found in HI, according to Kuramae et al (2013) who found this taxon as one of the groups involved in litter decomposition of maize leaves.…”

Land-use types and soil chemical properties influence soil microbial communities in the semiarid Loess Plateau region in China

“…The reason for this discrepancy may be related to the range of soil P (1.8–17 mg·kg −1 in Lauber10 and 1.65–3.31 mg·kg −1 in our study). Zygomycota , as saprotrophic species, are responsible for decomposing plant litter, alter soil chemical properties4350. This was mirrored by most of the differences between the dystrophic bare land site and the other forest sites.…”