Changes In Fungal Communities Research Articles

Changes in Soil Physicochemical Properties and Fungal Communities Following a Forest Fire in the Pine Forest of Uljin, Republic of Korea

Soil samples from the rhizosphere of pine (Pinus densiflora) stands in the fire-disturbed Uljin forest were collected to analyze their physicochemical properties and fungal communities. In the burned area, soil pH decreased by 0.56, and organic matter content decreased by 0.32%p compared to the undisturbed area. Fungal community analysis revealed that all alpha diversity indices decreased in the burned area, but there were no differences according to fire severity. Soil pH, available phosphorus, and total nitrogen showed a positive correlation with the alpha diversity. Additionally, beta diversity analysis also indicated significant differences in the fungal communities between the burned area and the control sites (p value = 0.031). The changes in fungal communities were considered to be influenced by the decline in the order Atheliales, genus Russula, and genus Trechispora. A prediction analysis of the functional traits of fungi showed that the number of fungi involved in nutrient absorption and decomposition decreased in the burned area. It seems that the soil restoration of pine forests is progressing very slowly, as the soil fungi related to nutrient absorption by pine trees have not recovered even 18 months after the forest fire. Therefore, it is necessary to monitor continuous fungal communities in pine forest restoration after a forest fire to determine forest ecosystem restoration success and stabilization.

Effect of mixed planting on soil nutrient availability and microbial diversity in the rhizosphere of Parashorea chinensis plantations.

Parashorea chinensis Wang Hsie (Pc) is an endangered tree species endemic to tropical and subtropical China. However, the acidic red soil areas where it is distributed generally face nutrient limitation. The study of the effects of mixed planting on soil biogeochemical processes contributes to the sustainable management and conservation of Pc. We selected pure and mixed stands of Pc and collected its rhizosphere and bulk soil samples to clarify the effect of mixed planting on the soil microbial community and the nutrient status. The results showed that (1) All stands were strongly acidic phosphorus-deficient soils (pH < 4.0, available phosphorus <10.0 mg·kg-1). There was a significant rhizosphere aggregation effect for soil organic C, total and available N and K, microbial biomass, and inorganic P fraction. (2) The mixed planting significantly increased the soil water content, organic C, available nutrients, the activities of β-1,4-glucosidase and urease, and microbial biomass. The inorganic P fractions are more influenced by rhizosphere, while organic P fractions are more influenced by tree species composition. (3) Fungi and their ecological functions are more susceptible to tree species than bacteria are, and have higher community compositional complexity and α-diversity in mixed plantations. And mixed planting can improve network complexity among key microorganisms. (4) The correlation between soil microorganisms and environmental factors was significantly higher in mixed forests than in pure forests. Soil organic C, available N and P, microbial biomass C and N, β-1,4-glucosidase, and stable P fractions were the key environmental factors driving changes in fungal and bacterial communities. In conclusion, the mixed planting patterns are more advantageous than pure plantations in improving soil physicochemical properties, enhancing nutrient effectiveness, and promoting microbial activities and diversity, especially Pc mixed with Eucalyptus grandis × E. urophylla is more conducive to soil improvement and sustainable management, which provides practical references for relocation protection of endangered tree species and species selection and soil fertility management in mixed planting. In addition, the study highlighted the key role of rhizosphere microenvironment in soil nutrient cycling and microbial community structure, which provides new perspectives for a deeper understanding of soil-microbe-plant interaction mechanisms.

Circadian rhythms of microbial communities and their role in regulating nitrogen and phosphorus cycling in the rhizosphere of tea plants

Abstract The circadian clock mediates metabolic functions of plants and rhythmically shapes structure and function of microbial communities in the rhizosphere. However, it is unclear how the circadian rhythm of plant hosts regulates changes in rhizosphere bacterial and fungal communities and nutrient cycles. In the present study, we measured diel changes in the rhizosphere of bacterial and fungal communities, and in nitrogen (N) and phosphorus (P) cycling in 20-year-old tea plantations. The fungal communities were more stable in their responses to circadian changes than bacterial communities in the rhizosphere of the variants LJ43 and ZC108. Nevertheless, fungal genera with circadian rhythms were more numerous and had a higher abundance at midnight. Organic P and N mineralization in the rhizosphere was more intensive in LJ43 under day-night alterations, while inorganic N and P cycling were more easily affected by circadian rhythms in ZC108. The rhizosphere denitrification encoded by the genes AOA and AOB was intensive in the morning, irrespective of tea species. Genes related to rhizosphere N fixation (nifH) and denitrification (nosZ and nirK) expressed at greater levels in ZC108, and they reached a peak at midnight. Moreover, the diel rhythm of rhizosphere microbial communities in ZC108 largely regulated dial changes in N and P cycling. These results suggested that the bacterial and fungal communities in the rhizosphere respond differently to circadian rhythms, and they vary between tea species. The timing of bacterial and fungal cycling largely regulates rhizosphere N and P cycling and their ecological functions.

Microbial colonisation rewires the composition and content of poplar root exudates, root and shoot metabolomes

BackgroundTrees are associated with a broad range of microorganisms colonising the diverse tissues of their host. However, the early dynamics of the microbiota assembly microbiota from the root to shoot axis and how it is linked to root exudates and metabolite contents of tissues remain unclear. Here, we characterised how fungal and bacterial communities are altering root exudates as well as root and shoot metabolomes in parallel with their establishment in poplar cuttings (Populus tremula x tremuloides clone T89) over 30 days of growth. Sterile poplar cuttings were planted in natural or gamma irradiated soils. Bulk and rhizospheric soils, root and shoot tissues were collected from day 1 to day 30 to track the dynamic changes of fungal and bacterial communities in the different habitats by DNA metabarcoding. Root exudates and root and shoot metabolites were analysed in parallel by gas chromatography-mass spectrometry.ResultsOur study reveals that microbial colonisation triggered rapid and substantial alterations in both the composition and quantity of root exudates, with over 70 metabolites exclusively identified in remarkably high abundances in the absence of microorganisms. Noteworthy among these were lipid-related metabolites and defence compounds. The microbial colonisation of both roots and shoots exhibited a similar dynamic response, initially involving saprophytic microorganisms and later transitioning to endophytes and symbionts. Key constituents of the shoot microbiota were also discernible at earlier time points in the rhizosphere and roots, indicating that the soil constituted a primary source for shoot microbiota. Furthermore, the microbial colonisation of belowground and aerial compartments induced a reconfiguration of plant metabolism. Specifically, microbial colonisation predominantly instigated alterations in primary metabolism in roots, while in shoots, it primarily influenced defence metabolism.ConclusionsThis study highlighted the profound impact of microbial interactions on metabolic pathways of plants, shedding light on the intricate interplay between plants and their associated microbial communities.2SWtA3_gUD-Xt4Z7N25436Video

Analysis of wheat fungal community succession in traditional storage structures using Illumina MiSeq sequencing technology

The diversity of fungi in wheat with different deoxynivalenol (DON) content at various periods post-harvest and in the environment of storage were investigated. The changes in DON content were measured with ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS), and an amplicon sequence analysis of fungi was performed in traditional storage structures using high-throughput sequencing. The changes in temperature, humidity, and CO2 concentration were collected by sensors. In addition, we analyzed principal component analysis, species composition, species differences, and community differences of fungi. There was an obvious separation of the fungal communities under different storage conditions and times. Many fungal genera were gradually decreasing during storage and were eventually undetectable, and many fungal genera that were undetectable at first gradually increased during storage and even became dominant fungal genera. The competition between fungi was fierce. The competition between fungi were affected by the presence of DON. As the initial DON content increased, the contribution of inter-group differences became more obvious. The temperature, humidity, and CO2 concentration of wheat in the silo's environment changed with extended storage time. The content of DON decreased with extended storage time. We had investigated the changes in DON content and their correlation with the changes in fungal communities and environmental factors, which showed a high degree of correlation. This study offers theoretical justification for optimizing safe wheat grain in traditional storage conditions.

Unveiling the influence of seawater intrusion and vegetation type on coastal arbuscular mycorrhizal fungal communities in China

AbstractContinuously rising sea levels pose severe threats to the diversity and stability of coastal ecosystems. However, the responses of endospheric and rhizospheric arbuscular mycorrhizal (AM) fungal communities to accelerated seawater intrusion and changing vegetation types unfortunately remains unknown. Such insights will assist in revealing the structure of AM fungi across different tidal zones, enabling the development of effective measures to conserve biodiversity. Here, we investigated changes in endospheric and rhizospheric AM fungal communities associated with four types of coastal vegetation in Dafeng City, Jiangsu Province, China, in response to sea level variations by analyzing their characteristics and connections to selected environmental factors. It was found that the AM fungal communities of coastal vegetation differed significantly in their compositions, diversity, and stability (the resilience or resistance of a community). Despite the responses of endospheric and rhizospheric AM fungi to soil environmental factors, the soil electrical conductivity, cation exchange content, and inorganic carbon were identified as core elements that influenced the characteristics of AM fungal communities between different coastal vegetation species. Lastly, the major endospheric and rhizospheric species of AM fungi were important predictors that explained much of the variation in the soil environment. Consequently, the dynamics of AM fungal communities were correlated with the plant–soil system under different conditions. Apart from the coastal vegetation species, the characteristics of AM fungal communities can also be driven by high salinity and the inorganic carbon content induced by the intrusion of seawater.

Gut mycobiome alterations and implications for liver diseases.

Chronic liver disease and its complications are a significant global health burden. Changes in fungal communities (mycobiome), an integral component of the gut microbiome, are associated with and contribute to the development of liver disease. Fungal dysbiosis can induce intestinal barrier dysfunction and allow fungal products to translocate to the liver causing progression of disease. This review explores recent progress in understanding the compositional and functional diversity of gut mycobiome signatures across different liver diseases. It delves into causative connections between gut fungi and liver diseases. We emphasize the significance of fungal translocation, with a particular focus on fungal-derived metabolites and immune cells induced by fungi, as key contributors to liver disease. Furthermore, we review the potential impact of the intrahepatic mycobiome on the progression of liver diseases.

Interaction Effects of Vegetation and Soil Factors on Microbial Communities in Alpine Steppe Under Degradation

To clarify the regulating effect of vegetation and soil factors on microbial communities in the alpine steppe under degradation on the Qinghai-Xizang Plateau, the alpine steppe in the Sanjiangyuan area of the Qinghai-Tibet Plateau was chosen. We analyzed the differences in vegetation and soil factors in different stages of degradation （non-degradation, moderate degradation, and severe degradation） and detected the variations in microbial community characteristics in the alpine steppe under different degradation stages using high-throughput sequencing technology. Eventually, redundancy analysis （RDA） and multiple regression matrixes （MRM） based on the similarity or dissimilarity matrix were used to identify key environmental factors regulating microbial （bacterial and fungal） community changes under degradation. The results showed that the degradation of the alpine steppe significantly changed the community coverage, height, biomass, and important value of graminae； significantly reduced the contents of soil organic matter, total nitrogen, total phosphorus, and silt； and increased the soil bulk density and sand content. Degradation did not change the composition of bacteria and fungi, but their composition proportions changed and also resulted in the loss of microbial richness （Chao1 index and Richness index） but did not significantly change the microbial diversity （Shannon index）. With the occurrence of degradation, the vegetation characteristics, soil physicochemical properties, and microbial diversity showed a consistent change trend. Combined with the characteristics of the network topology changes （the number of nodes and clustering coefficient significantly decreased）, it was found that degradation of the alpine steppe led to the decline of interspecies interactions, decentralization of network, and homogenization of microorganisms, but the cooperation relations among the species were maintained （positive correlation connections accounted for more than 90% in all degradation stages）. Under the alpine steppe degradation, the vegetation-soil interaction had the greatest effect on soil bacterial community, whereas soil physicochemical properties had the greatest influence on soil fungal community. Specifically, vegetation community height, biomass, and soil bulk density were the mutual factors regulating soil microorganisms, whereas the vegetation Simpson index, important value of graminae, soil total phosphorus, total potassium, and silt content were the unique factors affecting the soil bacterial community, and soil pH and total nitrogen content were the particular factors affecting the soil fungal community.

Salamander loss alters montane stream ecosystem functioning and structure through top‐down effects

AbstractAmphibians are among the most endangered taxa worldwide, but little is known about how their disappearance can alter the functioning and structure of freshwater ecosystems, where they live as larval stages. This is particularly true for urodeles, which often are key predators in these ecosystems. The fire salamander (Salamandra salamandra) is a common predator in European fresh waters, but the species is declining due to habitat loss and the infection by fungal pathogens. We studied the consequences of fire salamander loss from three montane streams, by comparing two key ecosystem processes (periphyton accrual and leaf litter decomposition) and the structure of three communities (periphytic algae, aquatic hyphomycetes and invertebrates) using stream enclosures with and without salamander larvae. Salamander loss did not cause changes in invertebrate abundance or community structure, except for one stream where abundance increased in the absence of salamander larvae. However, salamander loss led to lower periphyton accrual, changes in algal community structure and slower leaf litter decomposition, with no associated changes in fungal communities or microbial decomposition. The changes observed may have been caused by release of salamander predatory pressure on invertebrates, which could have promoted their grazing on periphyton, in contrast to their preference for leaf shredding in the presence of salamander. Our study demonstrates an important role of salamander larvae in montane streams through top‐down control of lower trophic levels and thus in regulating key stream ecosystem processes. Our results highlight the need for improving protection measures for amphibians to prevent these alterations on ecosystem structure and function.

Changes in the Arbuscular Mycorrhizal Fungal Community in the Roots of Eucalyptus grandis Plantations at Different Ages in Southern Jiangxi, China.

Eucalyptus roots form symbiotic relationships with arbuscular mycorrhizal (AM) fungi in soil to enhance adaptation in challenging environments. However, the evolution of the AM fungal community along a chronosequence of eucalypt plantations and its relationship with soil properties remain unclear. In this study, we evaluated the tree growth, soil properties, and root AM fungal colonization of Eucalyptus grandis W. Hill ex Maiden plantations at different ages, identified the AM fungal community composition by high-throughput sequencing, and developed a structural equation model among trees, soil, and AM fungi. Key findings include the following: (1) The total phosphorus (P) and total potassium (K) in the soil underwent an initial reduction followed by a rise with different stand ages. (2) The rate of AM colonization decreased first and then increased. (3) The composition of the AM fungal community changed significantly with different stand ages, but there was no significant change in diversity. (4) Paraglomus and Glomus were the dominant genera, accounting for 70.1% and 21.8% of the relative abundance, respectively. (5) The dominant genera were mainly influenced by soil P, the N content, and bulk density, but the main factors were different with stand ages. The results can provide a reference for fertilizer management and microbial formulation manufacture for eucalyptus plantations.

Characterisation and dynamics of the fungal communities of Avena fatua and Echinochloa crus‐galli seeds in soil seed bank

AbstractSurvival in the soil seed bank is critical to a weed maintaining populations in arable lands. The role of the seed‐borne fungi in seed decay or survival needs to be determined to find solutions for reducing the weed seed banks in environmentally friendly ways. In this study, changes of the fungal microbiome after seed burial were determined in two economically important weed species, wild oat and barnyard grass. Seeds collected in different populations were buried in two sites and exhumed at intervals over the period of 1.5 years to test the seed fate. Epiphytic and endophytic fungal microbiota of seeds was characterised using both culture‐based approach and NGS of ITS1 region. The proportion of visually intact seeds and decayed seeds was different between the two burial sites. The observed species richness of the isolated epiphytic fungi was higher in the fresh compared to the buried seeds. Fungal taxa determined by NGS amplicon sequencing only partly coincided with the isolated fungi, revealing higher diversity in buried seeds. The dynamic of taxonomic structure of the fungal community was less pronounced in wild oat seeds compared to the barnyard grass seeds, where both endophytic and epiphytic communities were significantly different in the buried seeds and differed between the burial sites. It can be concluded that the epiphytic fungal communities change after seed burial in both plant species, while endophytic communities are more stable in the intact seeds and changes of the fungal community in the seed endosphere may be associated with seed decay.

Grazing exclusion-induced changes in soil fungal communities in a highly desertified Brazilian dryland

Soil desertification poses a critical ecological challenge in arid and semiarid climates worldwide, leading to decreased soil productivity due to the disruption of essential microbial community processes. Fungi, as one of the most important soil microbial communities, play a crucial role in enhancing nutrient and water uptake by plants through mycorrhizal associations. However, the impact of overgrazing-induced desertification on fungal community structure, particularly in the Caatinga biome of semiarid regions, remains unclear. In this study, we assessed the changes in both the total fungal community and the arbuscular mycorrhizal fungal community (AMF) across 1. Natural vegetation (native), 2. Grazing exclusion (20 years) (restored), and 3. affected by overgrazing-induced degradation (degraded) scenarios. Our assessment, conducted during both the dry and rainy seasons in Irauçuba, Ceará, utilized Internal Transcribed Spacer (ITS) gene sequencing via Illumina® platform. Our findings highlighted the significant roles of the AMF families Glomeraceae (∼71% of the total sequences) and Acaulosporaceae (∼14% of the total sequences) as potential key taxa in mitigating climate change within dryland areas. Moreover, we identified the orders Pleosporales (∼35% of the total sequences) and Capnodiales (∼21% of the total sequences) as the most abundant soil fungal communities in the Caatinga biome. The structure of the total fungal community differed when comparing native and restored areas to degraded areas. Total fungal communities from native and restored areas clustered together, suggesting that grazing exclusion has the potential to improve soil properties and recover fungal community structure amid global climate change challenges.

Shifts in mycorrhizal types of fungi and plants in response to fertilisation, warming and herbivory in a tundra grassland.

Climate warming is severely affecting high-latitude regions. In the Arctic tundra, it may lead to enhanced soil nutrient availability and interact with simultaneous changes in grazing pressure. It is presently unknown how these concurrently occurring global change drivers affect the root-associated fungal communities, particularly mycorrhizal fungi, and whether changes coincide with shifts in plant mycorrhizal types. We investigated changes in root-associated fungal communities and mycorrhizal types of the plant community in a 10-yr factorial experiment with warming, fertilisation and grazing exclusion in a Finnish tundra grassland. The strongest determinant of the root-associated fungal community was fertilisation, which consistently increased potential plant pathogen abundance and had contrasting effects on the different mycorrhizal fungal types, contingent on other treatments. Plant mycorrhizal types went through pronounced shifts, with warming favouring ecto- and ericoid mycorrhiza but not under fertilisation and grazing exclusion. Combination of all treatments resulted in dominance by arbuscular mycorrhizal plants. However, shifts in plant mycorrhizal types vs fungi were mostly but not always aligned in their magnitude and direction. Our results show that our ability to predict shifts in symbiotic and antagonistic fungal communities depend on simultaneous consideration of multiple global change factors that jointly alter plant and fungal communities.

Amplicon-based metagenomics to study the effect of coir age and wood biochar on microbiome in relation to strawberry yield

In the UK, strawberry is mostly grown in coconut coir substrate under protection. Coir substrate is usually used only for one or two cropping seasons because the continuous reuse of coir without any treatment leads to yield decline. In this study, we investigated the changes in bacterial and fungal communities in strawberry roots and bulk coir in relation to (i) the coir substrate age (cropping seasons) and (ii) oak or beech biochar amendment at planting. Coir age did not affect fungal/bacterial alpha (within-sample) diversity but affected beta (between-sample) diversity. Amendment with either oak or beech biochar did not lead to significant changes in either alpha or beta diversity for both fungi and bacteria, but it did alter the relative abundance of 13 fungal ASVs. This study identified six bacterial and 20 fungal ASVs with a significant positive linear relationship with coir age and also eight bacterial and 22 fungal ASVs with a significant negative linear relationship with coir age. Notably, the observed strawberry yield decline in reused coir substrate could be associated with a generalist root pathogen, Ilyonectria destructans (ex. Cylindrocarpon destructans), of which the abundance increased annually by 225% and 426% in strawberry root and bulk coir, respectively. Future research is needed to confirm the role of I. destructans in reused coir on strawberry plant health and fruit productivity and then to identify management strategies for yield decline mitigation.

The Influence of Forest Litter Characteristics on Bacterial and Fungal Community Diversity in the Picea crassifolia Ecosystem on the Qinghai–Tibet Plateau

The biodiversity and activity of microorganisms are crucial for litter decomposition, but how litter traits at different stages of decomposition drive changes in microbial communities has yet to be thoroughly explored. In the typical alpine hilly area of the Qinghai–Tibet Plateau, three types of litter at different decomposition stages were selected under a natural Picea crassifolia (Picea crassifolia Kom.) forest: undecomposed (A-1), partially decomposed (A-2), and fully decomposed (A-3). By measuring physicochemical indicators, microbial diversity, and the composition of the litter at different decomposition stages, this study investigates the community changes and responses of bacteria to litter characteristic changes at different decomposition levels. The results show that with the increase in decomposition level, bacterial diversity increases, community structure changes, and network complexity gradually increases, while the changes in fungal communities are insignificant. Structural equation modeling indicates that the first principal component (PC1) of litter properties is significantly negatively correlated with bacterial diversity and positively correlated with bacterial community composition. There is no significant correlation between fungal diversity and community composition, indicating a closer relationship between bacteria and litter characteristics than fungi. In summary, with an increase in litter decomposition level, the diversity and network complexity of bacterial and fungal communities will significantly increase, which is related to the changes in various litter characteristics. This study provides a scientific basis for the regulatory mechanism of litter decomposition and turnover in the alpine hilly area of the Qinghai–Tibet Plateau, specifically in Picea crassifolia forests.

Disease-induced changes in bacterial and fungal communities from plant below- and aboveground compartments

The plant microbes are an integral part of the host and play fundamental roles in plant growth and health. There is evidence indicating that plants have the ability to attract beneficial microorganisms through their roots in order to defend against pathogens. However, the mechanisms of plant microbial community assembly from below- to aboveground compartments under pathogen infection remain unclear. In this study, we investigated the bacterial and fungal communities in bulk soil, rhizosphere soil, root, stem, and leaf of both healthy and infected (Potato virus Y disease, PVY) plants. The results indicated that bacterial and fungal communities showed different recruitment strategies in plant organs. The number and abundance of shared bacterial ASVs between bulk and rhizosphere soils decreased with ascending migration from below- to aboveground compartments, while the number and abundance of fungal ASVs showed no obvious changes. Field type, plant compartments, and PVY infection all affected the diversity and structures of microbial community, with stronger effects observed in the bacterial community than the fungal community. Furthermore, PVY infection, rhizosphere soil pH, and water content (WC) contributed more to the assembly of the bacterial community than the fungal community. The analysis of microbial networks revealed that the bacterial communities were more sensitive to PVY infection than the fungal communities, as evidenced by the lower network stability of the bacterial community, which was characterized by a higher proportion of positive edges. PVY infection further increased the bacterial network stability and decreased the fungal network stability. These findings advance our understanding of how microbes respond to pathogen infections and provide a rationale and theoretical basis for biocontrol technology in promoting sustainable agriculture.Key points• Different recruitment strategies between plant bacterial and fungal communities.• Bacterial community was more sensitive to PVY infection than fungal community.• pH and WC drove the microbial community assembly under PVY infection.

Deep nutrients and soil fungal communities support tomato fruit yield and quality in dry farm management systems

Changing climates are causing agricultural water shortages at unprecedented scales and magnitudes, especially in regions historically reliant on irrigation. Identifying and understanding systems of farming that allow continuity in agricultural operations in times of water scarcity are increasingly urgent needs. Vegetable dry farming relies on winter rains stored in soils to reduce irrigation to 0–2 events per season and has become prevalent on California’s Central Coast in recent decades. Until now, this system has been unexplored in scientific literature beyond extension publications, despite its promise as a model for low-water agriculture in arid regions. Dry farm management presents a unique challenge given that low water content restricts nutrient access in surface soils, which farmers typically target for fertility management. Managing soil nutrients at depth, as well as microorganisms that help plants access nutrients and alleviate water stress (e.g. arbuscular mycorrhizal fungi, or AMF) could be crucial to dry farm success. We engaged in a collaborative research design process with farmers managing seven commercial dry farm tomato fields to identify and answer three key management questions: 1. What are the depths at which nutrients influence harvest outcomes given low water content in surface soils?, 2. Are commercially available AMF inoculants effective at improving harvest outcomes?, and 3. How does the broader fungal community change in dry farm soils, and are those changes associated with harvest outcomes? Only soil nutrients below 60 cm depth were correlated with tomato yield and fruit quality. We identified a fungal class, Sordariomycetes, as a ‘signature’ fungal group in dry farm soils that distinguished them from irrigated management and correlated with positive fruit quality, while commercial AMF inoculation showed little benefit. These findings can inform management practices that optimize fruit yield and quality, and can guide farmers and policymakers alike in efforts to minimize agricultural water use.

Floristic changes and environmental drivers of soil fungi and archaea in different salt-tolerant plant communities in the intertidal habitat of coastal wetlands.

Microorganisms are crucial elements of terrestrial ecosystems, which play significant roles in improving soil physicochemical properties, providing plant growth nutrients, degrading toxic and harmful chemicals, and biogeochemical cycling. Variations in the types and quantities of root exudates among different plants greatly alter soil physicochemical properties and result in variations in the diversity, structure, and function of soil microorganisms. Not much is understood about the differences of soil fungi and archaea communities for different plant communities in coastal wetlands, and their response mechanisms to environmental changes. In this study, fungal and archaea communities in soils of Suaeda salsa, Phragmites australis, and Spartina alterniflora in the intertidal habitat of coastal wetlands were selected for research. Soil fungi and archaea were analyzed for diversity, community structure, and function using high throughput ITS and 16S rRNA gene sequencing. The study revealed significant differences in fungi and archaea's diversity and community structure in the rhizosphere soil of three plant communities. At the same time, there is no significant difference in the functional groups. SOM, TP, AP, MC, EC and SOM, TN, TP, AP, MC, EC are the primary environmental determinants affecting changes in soil fungal and archaeal communities, respectively. Variations in the diversity, community structure, and ecological functions of fungi and archaea can be used as indicators characterizing the impact of external disturbances on the soil environment, providing a theoretical foundation for the effective utilization of soil microbial resources, thereby achieving the goal of environmental protection and health promotion.

Dynamic changes in fungal communities and functions in different air-curing stages of cigar tobacco leaves.

Air curing (AC) plays a crucial role in cigar tobacco leaf production. The AC environment is relatively mild, contributing to a diverse microbiome. Fungi are important components of the tobacco and environmental microbiota. However, our understanding of the composition and function of fungal communities in AC remains limited. In this study, changes in the chemical constituents and fungal community composition of cigar tobacco leaves during AC were evaluated using flow analysis and high-throughput sequencing. The moisture, water-soluble sugar, starch, total nitrogen, and protein contents of tobacco leaves exhibited decreasing trends, whereas nicotine showed an initial increase, followed by a decline. As determined by high-throughput sequencing, fungal taxa differed among all stages of AC. Functional prediction showed that saprophytic fungi were the most prevalent type during the AC process and that the chemical composition of tobacco leaves is significantly correlated with saprophytic fungi. This study provides a deeper understanding of the dynamic changes in fungal communities during the AC process in cigar tobacco leaves and offers theoretical guidance for the application of microorganisms during the AC process.

Afforestation alters soil microbial community composition and reduces microbial network complexity in a karst region of Southwest China

AbstractSoil microbial community plays important roles in altering ecological processes and biogeochemical cycles in ecosystems. However, little is known about how afforestation influences the diversity, composition, and ecological network of soil microbial community in karst regions. In this study, soil samples were collected from one farmland (FL) and three afforestation lands including one bamboo forest (BA), one landscape tree planting forest (LAT), and one orange orchard (ORO) in a karst region of Southwest China. The bacterial and fungal communities were characterized using the high‐throughput sequencing approach, and soil properties including soil organic carbon, pH, soil water content, and soil total and available nutrient contents were measured under different land use treatments. Results showed that conversion from FL to BA and LAT significantly reduced the Shannon diversity of bacterial community. At the phylum level (top 10), genus level (top 30), and operational taxonomic units (OTUs) level, afforestation from FL resulted in significant changes in nine phyla, 24 genera, and 31.32% OTUs of bacterial community, and in three phyla, 13 genera, and 11.62% OTUs of fungal community. The number of nodes, number of negative edges, connectivity, average degree, and relative modularity of the microbial network under afforestation lands decreased by 9.33%–18.66%, 47.98%–72.75%, 0.45%–5.93%, 14.73%–22.29%, and 6.46%–23.50%, respectively, compared with FL. The soil organic carbon, total potassium and total phosphorus were identified as the key soil properties affecting the microbial community. Compared with LAT and ORO, the changes in bacterial and fungal communities under BA were more obvious because of the higher contents in soil organic carbon (13.48%) and total potassium (27.18%). In conclusion, afforestation significantly changed compositions and ecological network complexity of soil microbial community in karst regions, and conversion from FL to BA had stronger influences on the changes of soil microbial community than other afforestation lands in Southwest China. These findings provide the context necessary to evaluate the responses of soil microbial community to land use changes in karst regions.