High consistency between replicate 454 pyrosequencing analyses of ectomycorrhizal plant root samples

Area of Science:

• Mycology
• Molecular Ecology
• Bioinformatics

Background:

• Characterizing fungal communities is crucial for understanding plant-microbe interactions.
• Next-generation sequencing (NGS) technologies offer high-throughput analysis, but comparisons with conventional methods are essential.

Purpose of the Study:

• To compare the efficacy of 454 sequencing versus traditional cloning and Sanger sequencing for fungal community profiling.
• To assess the impact of laboratory procedures and sequencing methodology on fungal operational taxonomic unit (OTU) detection.

Main Methods:

• Fungal DNA from Bistorta vivipara root systems was amplified targeting the ITS1 region.
• Sequences were analyzed using 454 pyrosequencing and Sanger sequencing with clone libraries.
• Operational taxonomic units (OTUs) were defined using single linkage clustering at 97% similarity.

Main Results:

• Low overlap in identified fungal OTUs between 454 and Sanger sequencing methods was observed.
• Fungal community profiles clustered by sequencing methodology rather than by plant host.
• GC/AT content of OTUs correlated with their abundance differences between the two methods.

Conclusions:

• Sequencing methodology is a significant factor influencing fungal community composition results.
• Both methods showed high consistency between replicate samples, indicating minimal stochastic variation.
• Researchers should consider methodological biases when comparing fungal community studies.