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The water regime is often the primary force driving the evolution of freshwater lakes, but how soil microbes responded to this process is far from understood. This study sampled wetland soils from a shallow lake that experienced water regime changes, Poyang Lake of China, to explore the features of bacterial and fungal community in response to water level changes. The soil physicochemical properties, T-RFLP based community structures and soil activities (including basal respiration, microbial biomass and enzymes) were all determined. Soil microbial eco-function was captured by testing the carbon metabolism with Biolog-Ecoplate. The results showed remarkable influence of the water level gradients on the soil physicochemical properties, microbial community structures and soil activities. However, the carbon utilization profile exhibited weak connections with the environmental variables and microbial community structures (p > 0.05). The microbial activities were significantly correlated with both bacterial and fungal community structures. Our results also emphasized the ascendant role of the deterministic process in the assemblages of microbial community structures and functions in wetland. In conclusion, this study revealed the discrepancy between community structures and ecofunctions in response to water level gradients, and a relatively stable eco-function helped to maintain the ecosystem function of wetland from a long-term perspective.

Contigs with sequence homologies to cherry-associated luteovirus were identified by high-throughput sequencing analysis in two peach accessions. Complete genomic sequences of the two isolates of this virus were determined to be 5,819 and 5,814 nucleotides long, respectively. The genome of the new virus is typical of luteoviruses, containing eight open reading frames in a very similar arrangement. Its genomic sequence is 58-74% identical to those of other members of the genus Luteovirus. These sequences thus belong to a new virus, which we have named "peach-associated luteovirus".

Bacteria play a vital role in various biogeochemical processes in lacustrine sediment ecosystems. This study is among the first to investigate the spatial distribution patterns of bacterial community composition in the sediments of Poyang Lake, the largest freshwater lake of China. Sediment samples were collected from the main basins and mouths of major rivers that discharge into the Poyang Lake in May 2011. Quantitative PCR assay and pyrosequencing analysis of 16S rRNA genes showed that the bacteria community abundance and compositions of Poyang Lake sediment varied largely among sampling sites. A total of 25 phyla and 68 bacterial orders were distinguished. Burkholderiales, Gallionellales (Beta-proteobacteria), Myxococcales, Desulfuromonadales (Delta-proteobacteria), Sphingobacteriales (Bacteroidetes), Nitrospirales (Nitrospirae), Xanthomonadales (Gamma-proteobacteria) were identified as the major taxa and collectively accounted for over half of annotated sequences. Moreover, correlation analyses suggested that higher loads of total phosphorus and heavy metals (copper, zinc and cadmium) could enhance bacterial abundance in the sediment. Electronic supplementary materialThe online version of this article (doi:10.1186/s40064-016-2026-7) contains supplementary material, which is available to authorized users.