Similarities and Differences among Soil Fungal Assemblages in Managed Forests and Formerly Managed Forest Reserves

Dictyophora indusiata and Bacillus aryabhattai improve sugarcane yield by endogenously associating with the root and regulating flavonoid metabolism

Introduction

Endophytes play a significant role in regulating plant root development and facilitating nutrient solubilization and transportation. This association could improve plant growth. The present study has uncovered a distinct phenotype, which we refer to as "white root", arising from the intricate interactions between endophytic fungi and bacteria with the roots in a sugarcane and bamboo fungus (Dictyophora indusiata) intercropping system.

Methods

We investigated the mechanisms underlying the formation of this "white root" phenotype and its impact on sugarcane yield and metabolism by metabarcoding and metabolome analysis.

Results and Discussion

Initial analysis revealed that intercropping with D. indusiata increased sugarcane yield by enhancing the number of viable tillers compared with bagasse and no input control. Metabarcoding based on second-generation and third-generation sequencing indicated that D. indusiate and Bacillus aryabhattai dominates the fungal and bacterial composition in the "white root" phenotype of sugarcane root. The coexistence of D. indusiata and B. aryabhattai as endophytes induced plant growth-promoting metabolites in the sugarcane root system, such as lysoPC 18:1 and dihydrobenzofuran, probably contributing to increased sugarcane yield. Furthermore, the association also enhanced the metabolism of compounds, such as naringenin-7-O-glucoside (Prunin), naringenin-7-O-neohesperidoside (Naringin)*, hesperetin-7-O-neohesperidoside (Neohesperidin), epicatechin, and aromadendrin (Dihydrokaempferol), involved in flavonoid metabolism during the formation of the endophytic phenotype in the sugarcane root system. These observations suggest that the "white root" phenotype promotes sugarcane growth by activating flavonoid metabolism. This study reports an interesting phenomenon where D. indusiata, coordinate with the specific bacteria invade, forms a "white root" phenotype with sugarcane root. The study also provides new insights into using D. indusiata as a soil inoculant for promoting sugarcane growth and proposes a new approach for improve sugarcane cultivation.

Forest Type and Climate Outweigh Soil Bank in Shaping Dynamic Changes in Macrofungal Diversity in the Ancient Tree Park of Northeast China

The community structure of macrofungi is influenced by multiple complex factors, including climate, soil, vegetation, and human activities, making it challenging to discern their individual contributions. To investigate the dynamic changes in macrofungal diversity in an Ancient Tree Park located in Northeast China and explore the factors influencing this change, we collected 1007 macrofungi specimens from different habitats within the park and identified 210 distinct fungal species using morphological characteristics and ITS sequencing. The species were classified into 2 phyla, 6 classes, 18 orders, 55 families, and 94 genera. We found macrofungal compositions among different forest types, with the mixed forest displaying the highest richness and diversity. Climatic factors, particularly rainfall and temperature, positively influenced macrofungal species richness and abundance. Additionally, by analyzing the soil fungal community structure and comparing aboveground macrofungi with soil fungi in this small-scale survey, we found that the soil fungal bank is not the main factor leading to changes in the macrofungal community structure, as compared to the influence of climate factors and forest types. Our findings provide valuable insights into the dynamic nature of macrofungal diversity in the Ancient Tree Park, highlighting the influence of climate and forest type.

Metabarcoding Reveals Impact of Different Land Uses on Fungal Diversity in the South-Eastern Region of Antioquia, Colombia

Changes in soil fungal communities caused by land use have not been sufficiently studied in South American Andosols, which are considered key food production areas. Since fungal communities play an important role in soil functionality, this study analysed 26 soil samples of Andosols collected from locations devoted to conservation, agriculture and mining activities in Antioquia, Colombia, to establish differences between fungal communities as indicators of soil biodiversity loss using Illumina MiSeq metabarcoding on nuclear ribosomal ITS2 region. A non-metric multidimensional scaling allowed to explore driver factors of changes in fungal communities, while the significance of these variations was assessed by PERMANOVA. Furthermore, the effect size of land use over relevant taxa was quantified. Our results suggest a good coverage of fungal diversity with a detection of 353,312 high-quality ITS2 sequences. We found strong correlations of Shannon and Fisher indexes with dissimilarities on fungal communities (r = 0.94). These correlations allow grouping soil samples according to land use. Variations in temperature, air humidity and organic matter content lead to changes in abundances of relevant orders (Wallemiales and Trichosporonales). The study highlights specific sensitivities of fungal biodiversity features in tropical Andosols, which may serve as a basis for robust assessments of soil quality in the region.

Metabarcoding and Metabolome Analyses Reveal Mechanisms of Leymus chinensis Growth Promotion by Fairy Ring of Leucocalocybe mongolica

Fairy rings are a unique ecological phenomenon caused by the growth of the fungal mycelium in the soil. Fairy rings formed by Leucocalocybe mongolica (LM) are generally distributed in the Mongolian Plateau, where they promote plant growth without fertilization and alleviate fertilizer use. We previously investigated the soil factors regulating growth promotion in a fairy ring ecosystem; however, the aspects of the plant (Leymus chinensis, LC) that promote growth have not been explored. Therefore, the present study investigated the endophyte diversity and metabolome of LC in an LM fairy ring ecosystem. We analyzed the leaf and root samples of LC from the DARK (FR) and OUT (CK) zones. The fairy rings significantly improved the fungal diversity of roots and leaves and the bacterial diversity of leaves in the FR zone. Ralstonia was the dominant bacteria detected in the LC leaves. In addition, Marasmius, another fairy ring fungal genus, was also detected with a high abundance in the roots of the FR zone. Furthermore, widely targeted metabolome analysis combined with KEGG annotation identified 1011 novel metabolites from the leaves and roots of LC and seven pathways significantly regulated by the fairy ring in the FR zone. The fairy ring ecosystem significantly downregulated the flavonoid metabolism in the leaves and roots of LC. The correlation analysis found Ralstonia is a potential regulatory factor of flavonoid biosynthesis in LC. In addition, salicylic acid and jasmonic acid were found upregulated in the leaves, probably related to Marasmius enrichment. Thus, the study details plant factors associated with enhanced growth in an LM fairy ring ecosystem. These findings lay a theoretical foundation for developing the fairy ring ecosystem in an agricultural system.

Ecological Factors Influencing the Occurrence of Macrofungi from Eastern Mountainous Areas to the Central Plains of Jilin Province, China

Macrofungi are essential in forest ecological functioning. Their distribution and diversity are primarily impacted by vegetation, topography, and environmental factors, such as precipitation and temperature. However, the composition and topographical changes of the macrofungi between the eastern mountainous area and central plains of Jilin Province are currently unknown. For this study, we selected six investigational sites representing three different topographical research sites in Jilin Province to assess macrofungal diversity, and applied a quadrat sampling method. Macro- and micro-morphological characteristics combined with the molecular method were used to identify the collected macrofungi. Meanwhile, selected meteorological data were obtained for statistical analysis. As a result, 691 species were identified, of which Agarics were the most common, accounting for 60.23%, while the Cantharelloid fungi were the least common (0.91%). Furthermore, most of the shared genera (species) were saprophytic. The α diversity showed that the species diversity and richness in Longwan National Forest Park (B2) were the highest at the genus level. The mycorrhizal macrofungi proportion revealed that Quanshuidong Forest Farm (A1) was the healthiest. Finally, species composition similarity decreased with the transition from mountainous to hilly plains. We concluded that the occurrence of macrofungi was most influenced by vegetation. The air humidity, precipitation, and wind velocity were also found to significantly impact the occurrence of macrofungi. Finally, the mycorrhizal:saprophytic ratios and species similarity decreased with the transition from the mountainous area to the plains. The results presented here help elucidate the macrofungi composition and their relationship with environmental factors and topography in Jilin Province, which is crucial for sustainable utilization and future conservation.

Diversity of Microfungi in a High Radon Cave Ecosystem

Castañar Cave is a clear example of an oligotrophic ecosystem with high hygrothermal stability both seasonal and interannual and the particularity of registering extraordinary levels of environmental radiation. These environmental conditions make the cave an ideal laboratory to evaluate both the responses of the subterranean environment to sudden changes in the matter and energy fluxes with the exterior and also any impact derived from its use as a tourist resource under a very restrictive access regime. In 2008, a fungal outbreak provoked by a vomit contaminated the sediments which were removed and subsequently treated with hydrogen peroxide. Fungal surveys were carried out in 2008 and 2009. The visits were resumed in 2014. Here, 12 years after the outbreak, we present an exhaustive study on the cave sediments in order to know the distribution of the different fungal taxa, as well as the prevalence and spatio-temporal evolution of the fungi caused by the vomit over the years under the conditions of relative isolation and high radiation that characterize this cave.

Ectomycorrhizal Assemblages of Invasive Quercus rubra L. and Non-Invasive Carya Nutt. Trees under Common Garden Conditions in Europe

Invasive tree species change biodiversity, nutrient cycles, and ecosystem services, and can turn native ecosystems into novel ecosystems determined by invaders. In the acclimatization and invasion of alien tree species, the crucial role is played by ectomycorrhizal (ECM) fungi. We tested ECM fungi associated with Quercus rubra and Carya trees that are alien to Europe. Quercus rubra is among the most invasive tree species in Europe, and the Carya species are not considered invasive. Both form ectomycorrhizal symbiosis, and in their native range in North America, coexist in oak-hickory forests. Six study stands were located in Kórnik Arboretum: three for Q. rubra and three for Carya trees. Ectomycorrhizal fungi were assessed by molecular identification of ECM roots. We identified 73 ECM fungal taxa of 23 ECM phylogenetic lineages. All identified ECM fungi were native to Europe. Similar richness but different composition of ECM taxa were found on Q. rubra and Carya roots. Phylogenetic lineages /tomentella-thelephora, /russula-lactarius, and /genea-humaria were most abundant on both Carya and Q. rubra roots. Lineages /tuber-helvella and /entoloma were abundant only on Carya, and lineages /pisolithus-scleroderma and /cortinarius were abundant only on Q. rubra roots. Analysis of similarities revealed a significant difference in ectomycorrhizal assemblages between invasive Q. rubra and non-invasive Carya. Highlights: (1) under common garden conditions, ECM taxa richness was similar on Q. rubra and Carya roots; (2) ECM taxa composition differed between invasive Q. rubra and non-invasive Carya; (3) high abundance of long-distance exploration type (lineages from Boletales) was on Q. rubra; and (4) high abundance of short-distance exploration type (e.g., /tuber-helvella) was on Carya.

Karst rocky desertification diverged the soil residing and the active ectomycorrhizal fungal communities thereby fostering distinctive extramatrical mycelia

Ectomycorrhizal fungi (EMF) are mutualists that play crucial roles in liberation, nutrient acquisition, transfer of growth-limiting resources and provision of water to host plants in terrestrial ecosystems, particularly in stressed prone climates. In this study, a field-based experiment was performed in Yunnan, China to assess the effect of karst rocky desertification (KRD) and natural forests (non-KRD) sites on the richness and composition of EMF communities. Inert sand-filled mesh bags were employed to characterize the active EMF and quantify the production of extramatrical mycelium (EMM). Results indicated that, EMF exhibited a significant differentiation among KRD and non-KRD sites, richness and diversity were higher across KRD areas, whereas the evenness showed the opposite trend. Ascomycota and Zygomycota were greater across KRD sites, however, Basidiomycota showed no difference across both study sites. The relative abundance of Clavaria, Butyriboletus, Odontia, Phyloporus, Helvella, Russula and Tomentella were higher across the KRD sites, whereas, Clavulinopsis, Endogone, Amanita, Inocybe and Clavulina were higher across the non-KRD sites. It's worth noting that, saprophytic (SAP) fungal community was found to be more abundant in the soil than the mesh bags at both sites particularly at KRD sites, which likely provide more free space and less competition for the EMF to thrive well in the mesh bags. In similar pattern, ergosterol concentration in mesh bags was observed relatively higher at KRD sites than the non-KRD sites. The Entoloma, Amanita, and Sebacina were found to be substantially higher in mesh bags than soil across both sites. Delicatula, Helvella and Tomentella on the other hand, showed higher relative abundance in mesh bags than soil over KRD sites, however they did not differ across non-KRD sites. Taken together, the presented results highlight relationship between the EMF community and the complex KRD environment, which is very important for the restoration of disturbed karst landscapes.

Exploring the Relationships between Macrofungi Diversity and Major Environmental Factors in Wunvfeng National Forest Park in Northeast China

In this paper, we analyze the macrofungi communities of five forest types in Wunvfeng National Forest Park (Jilin, China) by collecting fruiting bodies from 2019–2021. Each forest type had three repeats and covered the main habitats of macrofungi. In addition, we evaluate selected environmental variables and macrofungi communities to relate species composition to potential environmental factors. We collected 1235 specimens belonging to 283 species, 116 genera, and 62 families. We found that Amanitaceae, Boletaceae, Russulaceae, and Tricholomataceae were the most diverse family; further, Amanita, Cortinarius, Lactarius, Russula, and Tricholoma were the dominant genera in the area. The macrofungi diversity showed increasing trends from Pinus koraiensis Siebold et Zuccarini forests to Quercus mongolica Fischer ex Ledebour forests. The cumulative species richness was as follows: Q. mongolica forest A > broadleaf mixed forest B > Q. mongolica, P. koraiensis mix forest D (Q. mongolica was the dominant species) > Q. mongolica and P. koraiensis mix forest C (P. koraiensis was the dominant species) > P. koraiensis forest (E). Ectomycorrhizal fungi were the dominant functional group; they were mainly in forest type A and were influenced by soil moisture content and Q. mongolica content (p < 0.05). The wood-rotting fungus showed richer species diversity than other forest types in broadleaf forests A and B. Overall, we concluded that most fungal communities preferred forest types with a relatively high Q. mongolica content. Therefore, the deliberate protection of Q. mongolica forests proves to be a better strategy for maintaining fungal diversity in Wunvfeng National Forest Park.

Structural and functional changes in the fungal community of plant detritus in an invaded Atlantic Forest

BACKGROUND

Changes in the fungal community in the litter decomposition by invasive plants can negatively impact nutrient cycling in natural ecosystems. One still does not know the dimension of this hypothesis, but apparently, it is not despicable. This study evaluated the assemblage composition of fungi during litter decomposition in areas of Atlantic Forest invaded or not invaded by Tradescantia zebrina using Illumina MiSeq and metabarcoding analysis.

RESULTS

The invaded sample showed significantly higher richness and a difference in the species dominance than the invaded litter. Ascomycota was the first most abundant phylum in both areas. Even so, the dissimilarity between areas can be evidenced. The fungal from Basidiomycota were very representative in the non-invaded areas (ranged from an abundance of 43.29% in the non-invaded to 2.35% in the invaded sample). The genus Lepiota can indicate the primary functional group related to biomass degradation and showed the might difference about the invaded areas due to its essential reduction by the invader. In the invaded sample, there was a total absence of the endophyte-undefined saprotroph guild. Also, some genera not taxonomically characterized were eliminated in the invaded sample, revealing that the fungal biodiversity of areas has not yet been thoroughly characterized.

CONCLUSIONS

Hence, makes impossible the real interpretation of the invasive plant impact, showing the importance of continuing research on fungal biodiversity. It is important to emphasize that the replacement of the native species by T. zebrina may be responsible for the elimination of fungal groups that have not yet been identified.

Structural and functional changes in the fungal community of plant detritus in an invaded Atlantic Forest

BACKGROUND

Changes in the fungal community in the litter decomposition by invasive plants can negatively impact nutrient cycling in natural ecosystems. One still does not know the dimension of this hypothesis, but apparently, it is not despicable. This study evaluated the assemblage composition of fungi during litter decomposition in areas of Atlantic Forest invaded or not invaded by Tradescantia zebrina using Illumina MiSeq and metabarcoding analysis.

RESULTS

The invaded sample showed significantly higher richness and a difference in the species dominance than the invaded litter. Ascomycota was the first most abundant phylum in both areas. Even so, the dissimilarity between areas can be evidenced. The fungal from Basidiomycota were very representative in the non-invaded areas (ranged from an abundance of 43.29% in the non-invaded to 2.35% in the invaded sample). The genus Lepiota can indicate the primary functional group related to biomass degradation and showed the might difference about the invaded areas due to its essential reduction by the invader. In the invaded sample, there was a total absence of the endophyte-undefined saprotroph guild. Also, some genera not taxonomically characterized were eliminated in the invaded sample, revealing that the fungal biodiversity of areas has not yet been thoroughly characterized.

CONCLUSIONS

Hence, makes impossible the real interpretation of the invasive plant impact, showing the importance of continuing research on fungal biodiversity. It is important to emphasize that the replacement of the native species by T. zebrina may be responsible for the elimination of fungal groups that have not yet been identified.

Metagenomic Analysis of Bacterial and Fungal Communities Inhabiting Shiro Dominant Soils of Two Production Regions of Tricholoma Matsutake S. Ito & S. Imai in Korea

Tricholoma matsutake is an ectomycorrhizal fungus that has obligate symbiotic relationships with Pinus densiflora. Its fruiting body has a distinctive flavor and is traded at a high price. Thus, it has been a significant source of income for rural communities in Korea. We hypothesized that biotic factors considerably influence the formation of the T. matsutake mushroom, and the soils producing T. matsutake share similar microbial characteristics. Therefore, the present study aimed to detect the specific fungal and bacterial groups in T. matsutake production soils (shiro+) and nonproduction soils (shiro−) of the Bonghwa and Yanyang regions via next-generation sequencing. In a total of 15 phyla, 36 classes, 234 genera of bacteria, six phyla, 29 classes, and 164 genera of fungi were detected from four samples at both sites. The species diversity of shiro+ soils was lower than the shiro− samples in both the fungal and bacterial groups. In addition, we did not find high similarities in the microbial communities between the shiro+ soils of the two regions. However, in the resulting differences between the fungal communities categorized by their trophic assembly, we found a distinguishable compositional pattern in the fungal communities from the shiro+ soils and the shiro− soils of the two sites. Thus, the similarity among the microbial communities in the forest soils may be due to the fact that the microbial communities in the T. matsutake dominant soils are closely associated with biotic factors and abiotic factors such as soil properties.