Nonpoint Source Pollution (NPSP) Induces Structural and Functional Variation in the Fungal Community of Sediments in the Jialing River, China

Abstract

Nonpoint source pollution (NPSP) from human production and life activities causes severe destruction in river basin environments. In this study, three types of sediment samples (A, NPSP tributary samples; B, non-NPSP mainstream samples; C, NPSP mainstream samples) were collected at the estuary of the NPSP tributary of the Jialing River. High-throughput sequencing of the fungal-speci c internal transcribed spacer (ITS) gene region was used to identify fungal taxa. The impact of NPSP on the aquatic environment of the Jialing River was revealed by analysing the community structure, community diversity and functions of sediment fungi. The results showed that the dominant phylum of sediment fungi was Rozellomycota, followed by Ascomycota, Chytridiomycota, Basidiomycota, Mortierellomycota and Zoopagomycota (relative abundance>1%). NPSP caused a signi cant increase in the relative abundances of Rozellomycota, Saccharomycetes, Microascales, Saccharomycetales, Branch02 and Branch03. In addition, it caused a signi cant decrease in the relative abundances of Chytridiomycota, Dothideomycetes, Capnodiales, Glomerellales, Xylariales and Chaetothyriales.Moreover, NPSP caused signi cant changes in the physicochemical properties of Jialing River sediments, such as pH and available nitrogen (AN), which signi cantly increased the species richness of fungi and caused signi cant changes in the fungal community β-diversity (P<0.05). pH, total phosphorus (TP) and AN were the main environmental factors affecting fungal communities in Jialing River sediments. The functions of sediment fungi mainly involved three types of nutrient metabolism (symbiotrophic, pathotrophic and saprotrophic) and 75 metabolic circulation pathways. NPSP signi cantly improved the NONOXIPENT-PWY, PENTOSE-P-PWY, and PWY-6837 metabolic circulation pathway functions (P<0.05) and inhibited the PWY-7118, PWY-5920, and PWY-6609 metabolic circulation pathway functions (P<0.05). Hence, NPSP causes changes in the community structure and functions of sediment fungi in Jialing River and destroys the stability of the Jialing River Basin ecosystem.

Effects of Snail Bellamya purificata Farming at Different Stocking Densities on the Algal and Fungal Communities in Sediment

“…The dominate phyla and genera (relative abundance > 1%) in the fungal community are shown in Figure 6. Similar with previous studies, most fungi could not be effectively annotated at either the phylum or genus level and has been represented as unclassified_k_Fungi in Figure 6 [27,37]. Excluding the unclassified fungal taxa, the dominate phyla were Ascomycota, Rozellomycota, As shown in Figure 7, the relative abundances of genera Paraconiothyrium a Penicillium were significantly different among the CON, LD, MD, and HD groups ( 0.05).…”

“…The dominate phyla and genera (relative abundance > 1%) in the fungal community are shown in Figure 6. Similar with previous studies, most fungi could not be effectively annotated at either the phylum or genus level and has been represented as unclassified_k_Fungi in Figure 6 [27,37]. Excluding the unclassified fungal taxa, the dominate phyla were Ascomycota, Rozellomycota, Basidiomycota, and Chytridiomycota, and the dominate genera were Scutellinia, unclassified_p_Rozellomycota, unclassified_p_Chytridiomycota, and Apiotrichum in the present study.…”

Effects of Moss-Dominated Biocrusts on Soil Microbial Community Structure in an Ionic Rare Earth Tailings Area of Southern China

“…However, for other non-bryophyte species, these rhizosphere bacteria are not necessarily members of the core rhizosphere microbiota [53]. Among the fungal flora, the core flora include Cladophialophora, Dokmaia, and Eurotiomycetes, which have obvious advantages in inhibiting bacteria, secreting amylase and oxidase, promoting protein, transforming starch into monosaccharides, and catalyzing the oxidation of polyphenols [54,55]. These microbial genera are likely to better adapt to acidic and barren conditions in soil and may respond more effectively to moss root signals, such as flavonoids, benzenes, and monoterpenes released by mosses.…”

Assessing land-use changes and carbon storage: a case study of the Jialing River Basin, China

“…However, it is significantly affected by economic development and urbanization under the national macro-policy, leading to drastic land-use changes in the JRB. These changes bring about a series of challenges to food production and ecological security 21 – 23 . Carbon storage in terrestrial ecosystems plays a crucial role as carbon sinks.…”

“…Studying the JRB land-use changes and their impact on carbon storage is vital. Although there have been numerous studies on the effects of land-use/cover changes or human activities on hydrological conditions 24 , soil erosion 25 , biodiversity 26 , and environmental pollution 23 in the JRB, there is a lack of up-to-date studies on historical land-use or carbon storage changes and future land-use simulations or carbon storage assessments.…”