High-throughput sequencing reveals the diversity and community structure of rhizosphere fungi of Ferula Sinkiangensis at different soil depths

Do mould inhibitors alter the microbial community structure and antibiotic resistance gene profiles on textiles?

Mould inhibitors are closely associated with human health and have been extensively applied to textiles to prevent mould and insect infestations. However, the impact of these mould inhibitors on the microbial community structure on textiles and antibiotic resistance gene (ARG) profiles remains largely unexplored. In this study, testing techniques, including high-throughput quantitative PCR and Illumina sequencing, were employed to analyse the effects of three types of mould inhibitors -para-dichlorobenzene (PDCB), naphthalene, and natural camphor balls-on the composition of microbial communities and ARG profiles. The microbial mechanisms underlying these effects were also investigated. The experiments revealed that PDCB reduced the diversity of bacterial communities on textiles, whereas naphthalene and natural camphor balls exerted relatively minor effects. In contrast with bacterial diversity, PDCB enhanced the diversity of fungal communities on textiles, but significantly reduced their abundance. Naphthalene had the least impact on fungal communities; however, it notably increased the relative abundance of Basidiomycota. All three types of mould inhibitors substantially altered ARG profiles. Potential mechanisms responsible for the alterations in ARG profiles include microbial community succession and horizontal gene transfer mediated by mobile genetic elements. PDCB prominently increased the abundance of ARGs, mainly attributable to the relative enrichment of potential hosts (including certain γ-Proteobacteria and Bacillales) for specific ARGs. Thus, this study has important implications for the selection of mould inhibitors, as well as the assessment of microbial safety in textiles.

Shifts in the diversity of root endophytic microorganisms across the life cycle of the ratooning rice Jiafuzhan

The diversity of root endophytic microorganisms, which is closely related to plant life activities, is known to vary with the plant growth stage. This study on the ratooning rice Jiafuzhan explored the diversity of the root endophytic bacteria and fungi and their dynamics during the plant life cycle. By sequencing the 16S ribosomal ribonucleic acid (16S rRNA) and internal transcribed spacer (ITS) genes, 12,154 operational taxonomic units (OTUs) and 497 amplicon sequence variants (ASVs) were obtained, respectively. The root endophytic microorganisms of rice in the seedling, tillering, jointing, heading, and mature stages of the first crop and at 13, 25, and 60 days after regeneration (at the heading, full heading, and mature stages of the second crop, respectively) were analyzed using diversity and correlation analyses. There were significant differences in the α-diversity and β-diversity of root endophytic bacteria and fungi in the growth stage. Additionally, linear discriminant analysis (LDA) effect size (LEfSe) analysis revealed biomarker bacteria for each growth stage, but biomarker fungi did not exist in every stage. Moreover, the correlation analysis showed that the bacterial and fungal biomarkers interacted with each other. Furthermore, the nitrogen-fixing genus Bradyrhizobium existed in all growth stages. These findings indicate the pattern of root endophytic microorganisms of ratooning rice at different growth stages, and they provide new insights into the high yield of the second crop of ratooning rice (in light of the abundance of various bacteria and fungi).

Discovery of Fusarium proliferatum f. sp. malus domestica Causing Apple Replant Disease in China

Apple replant disease (ARD) is the most serious threat facing the apple industry globally. ARD is mainly manifested as decreased plant growth, serious root rot disease, and considerable yield loss. Microbial factors are the dominant factors leading to the occurrence of ARD. Research on soil-borne pathogenic fungi leading to the occurrence of ARD in China is limited. In the present study, we selected 16 replanting orchards from the Northwest Loess region and around the Bohai Gulf. Diseased roots and rhizosphere soil from healthy apple trees and trees showing ARD symptoms were sampled at random. High-throughput sequencing was used to study the fungal communities in the rhizosphere soil, which showed that the composition of the rhizosphere soil fungal community of ARD-symptomatic and healthy apple trees was different. Nectriaceae at the family level and Fusarium at the genus level dominated the rhizosphere soil fungal community in the two regions, while for healthy apple trees, the relative abundance of Mortierella, Minimedusa, Tetracladium, and Chaetomium was higher. Tissue separation and serial dilution were used to separate fungi, and a total of 89 genera and 219 species were obtained, most of which were Fusarium. Fusarium was further confirmed to be the most abundant pathogen species leading to the occurrence of ARD in China through pathogenicity assays. A pathogenicity assay was carried out by the dip-and-cut technique using different host plants. It was found that Fusarium MR5 showed strong aggressiveness to apple rootstocks. Diseased seedlings specifically exhibited chlorosis of the leaves, browning from the edge of the leaf, followed by rolling and yellowing of the leaves, resulting in wilting and eventually death. Strain MR5 was preliminarily identified as F. proliferatum according to the morphological and cultural characteristics. A maximum likelihood analysis of identities based on six gene sequence (ITS, TUB2, IGS, mtSSU, RPB2, and the TEF gene) alignments between the MR5 strain and other strains showed 99 to 100% homology with F. proliferatum. Based on our test results, strain MR5 was identified as F. proliferatum f. sp. malus domestica, which is of great significance for finding new measures to control ARD in China.

Ecological and Oceanographic Perspectives in Future Marine Fungal Taxonomy

Marine fungi are an ecological rather than a taxonomic group that has been widely researched. Significant progress has been made in documenting their phylogeny, biodiversity, ultrastructure, ecology, physiology, and capacity for degradation of lignocellulosic compounds. This review (concept paper) summarizes the current knowledge of marine fungal diversity and provides an integrated and comprehensive view of their ecological roles in the world's oceans. Novel terms for 'semi marine fungi' and 'marine fungi' are proposed based on the existence of fungi in various oceanic environments. The major maritime currents and upwelling that affect species diversity are discussed. This paper also forecasts under-explored regions with a greater diversity of marine taxa based on oceanic currents. The prospects for marine and semi-marine mycology are highlighted, notably, technological developments in culture-independent sequencing approaches for strengthening our present understanding of marine fungi's ecological roles.

Mortierellaceae from subalpine and alpine habitats: new species of Entomortierella, Linnemannia, Mortierella, Podila and Tyroliella gen. nov

Fungi are incredibly diverse, but they are unexplored, especially in the subalpine and alpine zone. Mortierellaceae are certainly one of the most abundant, species-rich, and widely distributed cultivable soil fungal families in terrestrial habitats, including subalpine and alpine zones. The phylogeny of Mortierellaceae was recently resolved based on current state of the art molecular techniques, and the paraphyletic genus Mortierella sensu lato (s.l.) was divided into 13 monophyletic genera. Our extensive sampling campaigns in the Austrian Alps resulted in 139 different Mortierellaceae pure culture isolates representing 13 new species. For the definition of taxa, we applied both classical morphological criteria, as well as modern DNA-based methods. Phylogenetic relationships were resolved based on the ribosomal DNA internal transcribed spacer (rDNA ITS), the large subunit (LSU), and the DNA-directed RNA polymerase II largest subunit 1 (RPB1). In this study, we proposed a new genus and described 13 new species belonging to the genera Entomortierella, Linnemannia, Mortierella and Podila. In addition, we proposed eight new combinations, re-defined E. jenkinii at species level, defined a neotype for M. alpina and lecto- as well as epitypes for M. fatshederae, M. jenkinii, and M. longigemmata. The rDNA ITS region is generally applied as classical barcoding gene for fungi. However, the obtained phylogenetic resolution is often too low for an accurate identification of closely related species of Mortierellaceae, especially for small sampling sizes. In such cases, unambiguous identification can be obtained based on morphological characters of pure culture isolates. Therefore, we also provide dichotomous keys for species identification within phylogenetic lineages. Taxonomic novelties: new genus: Tyroliella Telagathoti, Probst & Peintner; New species: Entomortierella galaxiae Telagathoti, M. Probst & Peintner, Linnemannia bainierella Telagathoti, M. Probst & Peintner, Linnemannia stellaris Telagathoti, M. Probst & Peintner, Linnemannia nimbosa Telagathoti, M. Probst & Peintner, Linnemannia mannui Telagathoti, M. Probst & Peintner, Linnemannia friederikiana Telagathoti, M. Probst & Peintner, Linnemannia scordiella Telagathoti, M. Probst & Peintner, Linnemannia solitaria Telagathoti, M. Probst & Peintner, Mortierella triangularis Telagathoti, M. Probst & Peintner, Mortierella lapis Telagathoti, M. Probst & Peintner, Podila himami Telagathoti, M. Probst & Peintner, Podila occulta Telagathoti, M. Probst & Peintner, Tyroliella animus-liberi Telagathoti, Probst & Peintner; New combinations: Entomortierella basiparvispora (W. Gams & Grinb.) Telagathoti, M. Probst & Peintner, Entomortierella jenkinii (A.L. Sm.) Telagathoti, M. Probst & Peintner; Entomortierella sugadairana (Y. Takash. et al.) Telagathoti, M. Probst & Peintner, Linnemannia zonata (Linnem. ex W. Gams) Telagathoti, M. Probst & Peintner, Linnemannia fluviae (Hyang B. Lee et al.) Telagathoti, M. Probst & Peintner, Linnemannia biramosa (Tiegh.) Telagathoti, M. Probst & Peintner, Linnemannia cogitans (Degawa) Telagathoti, M. Probst & Peintner, Tyroliella pseudozygospora (W. Gams & Carreiro) Telagathoti, M. Probst & Peintner; Epitypifications (basionyms): Mortierella bainieri var. jenkinii A.L. Sm., Mortierella fatshederae Linnem., Mortierella longigemmata Linnem. Neotypification (basionym): Mortierella alpina Peyronel. Citation: Telagathoti A, Probst M, Mandolini E, Peintner U (2022). Mortierellaceae from subalpine and alpine habitats: new species of Entomortierella, Linnemannia, Mortierella, Podila and Tyroliella gen. nov. Studies in Mycology 103: 25-58. doi: 10.3114/sim.2022.103.02.

Asafoetida exerts neuroprotective effect on oxidative stress induced apoptosis through PI3K/Akt/GSK3β/Nrf2/HO-1 pathway

Background

Alzheimer's Disease (AD) is a serious neurodegenerative disease and there is currently no effective treatment for AD progression. The use of TCM as a potential treatment strategy for AD is an evolving field of investigation. Asafoetida (ASF), an oleo-gum-resin isolated from Ferula assa-foetida root, has been proven to possess antioxidative potential and neuroprotective effects, which is closely associated with the neurological disorders. However, the efficacy and further mechanisms of ASF in AD experimental models are still unclear.

Methods

A cognitive impairment of mouse model induced by scopolamine was established to determine the neuroprotective effects of ASF in vivo, as shown by behavioral tests, biochemical assays, Nissl staining, TUNEL staining, Immunohistochemistry, western blot and qPCR. Furthermore, the PC12 cells stimulated by H₂O₂ were applied to explore the underlying mechanisms of ASF-mediated efficacy. Then, the UPLCM analysis and integrated network pharmacology approach was utilized to identified the main constitutes of ASF and the potential target of ASF against AD, respectively. And the main identified targets were validated in vitro by western blot, qPCR and immunofluorescence staining.

Results

In vivo, ASF treatment significantly ameliorated cognitive impairment induced by scopolamine, as evidenced by improving learning and memory abilities, and reducing neuronal injury, cholinergic system impairment, oxidative stress and apoptosis in the hippocampus of mice. In vitro, our results validated that ASF can dose-dependently attenuated H₂O₂-induced pathological oxidative stress in PC12 cells by inhibiting ROS and MDA production, as well as promoting the activities of SOD, CAT, GSH. We also found that ASF can significantly suppressed the apoptosis rate of PC12 cells increased by H₂O₂ exposure, which was confirmed by flow cytometry analysis. Moreover, treatment with ASF obviously attenuated H₂O₂-induced increase in caspase-3 and Bax expression levels, as well as decrease in Bcl-2 protein expression. KEGG enrichment analysis indicated that the PI3K/Akt/GSK3β/Nrf2 /HO-1pathway may be involved in the regulation of cognitive impairment by ASF. The results of western blot, qPCR and immunofluorescence staining of vitro assay proved it.

Conclusions

Collectively, our work first uncovered the significant neuroprotective effect of ASF in treating AD in vivo. Then, we processed a series of vitro experiments to clarify the biological mechanism action. These data demonstrate that ASF can inhibit oxidative stress induced neuronal apoptosis to foster the prevention of AD both in vivo and in vitro, and it may exert the function of inhibiting AD through PI3K/Akt/GSK3β/Nrf2/HO-1pathway.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-022-00630-7.

Nutrient variation induced by rodent disturbance in Haloxylon ammodendron as a target transfer strategy

Nutrients form a link between herbivores and plant. This study explored the physiological and ecological response mechanism of Haloxylon ammodendron population to rodent disturbance in Gurbantunggut Desert from the perspective of nutrient cycle. Through field investigation, we quantified rodent disturbance intensity (DI) to H. ammodendron and analyzed the ecological response mechanism of H. ammodendron population to rodent disturbance from the perspective of plant and soil nutrient cycling and changes. The results indicated that moderate rodent DI (number of effective burrows = 3-6) was the maximum limit that can be tolerated by H. ammodendron; the threshold for optimal H. ammodendron response to rodent disturbance was mild (number of burrows = 1-3). Meanwhile, the rodent disturbance caused significant nutrient enrichment (e.g., organic carbon, available phosphorus, and available potassium) in the deeper soil (at 20-40 and 40-60 cm depth) and significantly reduced the soil total salt content (p < .05). Furthermore, as the DI increased, the branches of H. ammodendron showed significantly increased soluble total sugar, crude fiber, and total nitrogen contents (p < .05) but significantly decreased crude fat and crude protein contents (p < .05); these results are related to the nutritional target transfer strategy evolved by H. ammodendron for long-term resistance to rodent disturbance. The current study clarified the optimal disturbance model for mutually beneficial H. ammodendron-great gerbil relationship, on the basis of which the ecological response mechanism of H. ammodendron population to rodent disturbance in deserts was illustrated. The current study provides a scientific basis for the protection mechanisms of desert plants to rodent disturbance.

Sugarcane-Legume Intercropping Can Enrich the Soil Microbiome and Plant Growth

Soil microbes have a direct impact on plant metabolism and health. The current study investigates the comparative rhizobiome between sugarcane monoculture and sugarcane–soybean intercropping. A greenhouse experiment was performed with two treatments: (1) sugarcane monoculture and (2) sugarcane–soybean intercropped. We used a high-throughput sequencing (HTS) platform to analyze the microbial community. We used the 16S rRNA gene and internal transcribed spacer region primers to identify the microbial diversity. HTS results revealed that a total of 2,979 and 124 bacterial and fungal operational taxonomic units (OTUs) were observed, respectively. Microbial diversity results concluded that the intercropping system has a beneficial impact on soil microbes. The highest numbers of bacterial and fungal OTUs were found in the intercropping system, and these results also collaborated with quantitative PCR results. Additionally, intercropped sugarcane plants showed a higher weight of above- and below-ground parts than the monoculture. Soil chemical analysis results also complemented that the intercropping system nourished organic carbon, total nitrogen, and soil enzyme activities. Correlation analysis of the diversity index and abundance concluded that soil nutrient content positively influenced the microbial abundance that improves plant growth. The present study frames out the profound insights of microbial community interaction under the sugarcane–soybean intercropping system. This information could help improve or increase the sugarcane crop production without causing any negative impact on sugarcane plant growth and development.

Effects of Biogas Slurry Combined With Chemical Fertilizer on Soil Bacterial and Fungal Community Composition in a Paddy Field

The application of biogas slurry and chemical fertilizer in paddy fields can be a practical method to reduce the environmental risk and utilize the nutrients of biogas slurry. The responses of bacterial and fungal communities to the application of biogas slurry and chemical fertilizer are important reflections of the quality of the ecological environment. In this study, based on a 3-year field experiment with different ratios of biogas slurry and chemical fertilizer (applying the same pure nitrogen amount), the Illumina MiSeq platform was used to investigate the bacterial and fungal community diversity and composition in paddy soil. Our results revealed that compared with the observations under regular chemical fertilization, on the basis of stable paddy yield, the application of biogas slurry combined with chemical fertilizer significantly enhanced the soil nutrient availability and bacterial community diversity and reduced the fungal community diversity. Dissolved organic carbon (DOC), DOC/SOC (soil organic carbon), available nitrogen (AN) and available phosphorus (AP) were positively correlated with the bacterial community diversity, but no soil property was significantly associated with the fungal community. The bacterial community was primarily driven by the application of biogas slurry combined with chemical fertilizer (40.78%), while the fungal community was almost equally affected by the addition of pure biogas slurry, chemical fertilizer and biogas slurry combined with chemical fertilizer (25.65–28.72%). Biogas slurry combined with chemical fertilizer significantly enriched Proteobacteria, Acidobacteria, Planctomycetes, Rokubacteria, and Ascomycota and depleted Chloroflexi, Bacteroidetes, Crenarchaeota, Basidiomycota, and Glomeromycota. The observation of the alteration of some bacteria- and fungus-specific taxa provides insights for the proper application of biogas slurry combined with chemical fertilizer, which has the potential to promote crop growth and inhibit pathogens.

Differential response of soil microbial and animal communities along the chronosequence of Cunninghamia lanceolata at different soil depth levels in subtropical forest ecosystem

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We investigated the assembly of soil bacteria, fungi, archaea, protists & animals across different soil depths in five stand ages.

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Soil biotic communities exhibited a decreasing trend in alpha diversity with increasing soil depth.

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Acidobacteriia, Agaricomycetes, Bathyarchaeia, Chlorophyceae and Clitellata, were most abundant classes.

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Total nitrogen, available phosphorus and pH were the most influencing factors for changes in soil biotic communities.

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As compared to soil depth, stand age was not dominatingly influencing the structure of other biotic communities.

Introduction

Soil biota plays a crucial role in the terrestrial ecosystem. There is growing momentum to understand the community structure and diversity of total belowground soil biota across large ecological scales. Soil biota follow divergent trends with respect to soil physiochemical properties in different ecosystems; however, little is known about their response to stand development across multiple soil depths in Chinese fir plantations, which is the most important tree species across all over China, popular for its timber production.

Objectives

Here, we investigated the community assembly of soil bacteria, fungi, archaea, protists and animals across three different vertical soil profiles (0–10, 10–20, 20–40 cm) using a chronosequence of Chinese fir representing five different stand ages (5, 8, 21, 27, 40 years) in South China.

Methods

High throughput illumine Hiseq2500 sequencing.

Results

Our results showed that soil biotic communities exhibited a decreasing trend in alpha diversity of bacteria, fungi, protists and animals with increasing soil depth; however, archaea showed an opposite trend. Most abundant soil bacterial, fungal, archaeal, protist and animal classes were Acidobacteriia, Agaricomycetes, Bathyarchaeia, Chlorophyceae and Clitellata, respectively. Correlation of vertical distribution of biotic communities and variations in soil physiochemical properties explained that total nitrogen (TN), available phosphorus (AP) and pH were the most influencing factors for changes in soil biotic communities. Although the stand age was a contributing factor for fungal and animal beta diversity, however, as compared to soil depth, it was not dominatingly influencing the structure of other biotic communities.

Conclusions

Collectively, these results reveal a new perspective on the vertical variation and distinct response patterns of soil biotic communities at a fine scale across different stand ages of Chinese fir plantations.

Fungal Community Composition and Diversity Vary With Soil Horizons in a Subtropical Forest

Soil fungal communities, which drive many ecosystem processes, vary across soil horizons. However, how fungal communities are influenced by soil horizon layers remains largely unstudied. In this study, soil samples were collected from the organic horizon (O horizon) and mineral matter horizon (M horizon) in two sites of Dabie Mountain, China, and the effects of the two horizons on the soil fungal community composition were assessed based on Illumina MiSeq sequencing. Our results showed that soil fungal community composition varied with soil horizons, and soil fungal species richness and diversity in the O horizon were significantly higher than that in the M horizon. Total organic carbon (TOC), total organic nitrogen (TON), alkali-hydrolyzable nitrogen (AHN), available potassium (AK), and available phosphorus (AP) significantly influenced fungal community composition, abundance, and diversity across the two horizons (P < 0.05). Furthermore, precipitation was found to have a significant effect on fungal community composition. Our results demonstrate changes in fungal communities across soil horizons and highlight the importance of soil organic matter on fungal communities and diversity.

Draft Genomes and Comparative Analysis of Seven Mangrove Rhizosphere-Associated Fungi Isolated From Kandelia obovata and Acanthus ilicifolius

Mangroves are one of the most productive and biologically diverse ecosystems, with unique plants, animals, and microorganisms adapted to the harsh coastal environments. Although fungi are widely distributed in the mangrove ecosystem and they are playing an important role in the decomposition of organic matter, their genomic profiles are still poorly understood. In this study, we isolated seven Ascomycota fungi (Westerdykella dispersa F012, Trichoderma lixii F014, Aspergillus tubingensis F023, Penicillium brefeldianum F032, Neoroussoella solani F033, Talaromyces fuscoviridis F034, and Arthrinium marii F035) from rhizospheres of two mangroves of Kandelia obovata and Acanthus ilicifolius. We sequenced and assembled the whole genome of these fungi, resulting in size ranging from 29 to 48 Mb, while contig N50 from 112 to 833 Kb. We generated six novel fungi genomes except A. tubingensis, and the gene completeness and genome completeness of all seven genomes are higher than 94%. Comparing with non-mangrove fungi, we found Carbohydrate-Binding Modules (CBM32), a subfamily of carbohydrate active enzymes, only detected in two mangrove fungi. Another two subfamilies, Glycoside Hydrolases (GH6) and Polysaccharide Lyases (PL4), were significantly different in gene copy number between K. obovata and A. ilicifolius rhizospheres (P-value 0.041 for GH6, 0.047 for PL4). These findings may indicate an important influence of mangrove environments or hosts on the ability of decomposition in rhizosphere fungi. Secondary metabolite biosynthesis gene clusters were detected and we found the mangrove fungi averagely contain 18 Type I Polyketide (t1pks) synthase, which was significantly higher than 13 in non-mangrove fungi (P-value 0.048), suggesting their potential roles in producing bioactive compounds that important for fungi development and ecology. We reported seven mangrove-associated fungal genomes in this study and compared their carbohydrate active enzymes and secondary metabolites (SM) genes with those of non-mangrove fungi, and the results suggest that there are differences in genetic information among fungi in different habitats.

High-throughput sequencing analysis of the rhizosphere arbuscular mycorrhizal fungi (AMF) community composition associated with Ferula sinkiangensis

BACKGROUND

Ferula sinkiangensis is an increasingly endangered medicinal plant. Arbuscular mycorrhiza fungi (AMF) are symbiotic microorganisms that live in the soil wherein they enhance nutrient uptake, stress resistance, and pathogen defense in host plants. While such AMF have the potential to contribute to the cultivation of Ferula sinkiangensis, the composition of AMF communities associated with Ferula sinkiangensis and the relationship between these fungi and other pertinent abiotic factors still remains to be clarified.

RESULTS

Herein, we collected rhizosphere and surrounding soil samples at a range of depths (0-20, 20-40, and 40-60 cm) and a range of slope positions (bottom, middle, top). These samples were then subjected to analyses of soil physicochemical properties and high-throughput sequencing (Illumina MiSeq). We determined that Glomus and Diversispora species were highly enriched in all samples. We further found that AMF diversity and richness varied significantly as a function of slope position, with this variation primarily being tied to differences in relative Glomus and Diversispora abundance. In contrast, no significant relationship was observed between soil depth and overall AMF composition, although some AMF species were found to be sensitive to soil depth. Many factors significantly affected AMF community composition, including organic matter content, total nitrogen, total potassium, ammonium nitrogen, nitrate nitrogen, available potassium, total dissolvable salt levels, pH, soil water content, and slope position. We further determined that Shannon diversity index values in these communities were positively correlated with total phosphorus, nitrate-nitrogen levels, and pH values (P < 0.05), whereas total phosphorus, total dissolvable salt levels, and pH were positively correlated with Chao1 values (P < 0.05).

CONCLUSION

In summary, our data revealed that Glomus and Diversispora are key AMF genera found within Ferula sinkiangensis rhizosphere soil. These fungi are closely associated with specific environmental and soil physicochemical properties, and these soil sample properties also differed significantly as a function of slope position (P < 0.05). Together, our results provide new insights regarding the relationship between AMF species and Ferula sinkiangensis, offering a theoretical basis for further studies of their development.

Community structure and diversity of the microbiomes of two microhabitats at the root-soil interface: implications of meta-analysis of the root-zone soil and root endosphere microbial communities in Xiong'an New Area

The diversity of the microbial compositions of the root-zone soil (the rhizosphere-surrounding soil) and root endosphere (all inner root tissues) of Pinus tabulaeformis Carr. and Ginkgo biloba L. were evaluated in Xiong'an New Area using high-throughput sequencing; the influence of the soil edaphic parameters on microbial community compositions was also evaluated. Our results showed that both the taxonomic and phylogenetic diversities of the root endosphere were lower than those of the root-zone soil, but the variation in the endosphere microbial community structure was remarkably higher than that of the root-zone soil. Spearman correlation analysis showed that the soil organic matter, total nitrogen, total phosphate, total potassium, ratio of carbon to nitrogen, and pH significantly explained the α-diversity of the bacterial community and that total nitrogen differentially contributed to the α-diversity of the fungal community. Variation partitioning analysis showed that plant species had a greater influence on microbial composition variations than did any other soil property, although soil chemical parameters explained more variation when integrated. Together, our results suggest that both plant species and soil chemical parameters played a critical role in shaping the microbial community composition.

Comparative Analysis of Fungal Diversity in Rhizospheric Soil from Wild and Reintroduced Magnolia sinica Estimated via High-Throughput Sequencing

Magnolia sinica is a critically endangered species and considered a “plant species with extremely small populations” (PSESP). It is an endemic species in southeastern Yunnan Province, China, with reproductive barriers. Rhizosphere fungi play a crucial role in plant growth and health. However, the composition, diversity, and function of fungal communities in wild and reintroduced M. sinica rhizospheres remain unknown. In this study, Illumina sequencing of the internal transcribed spacer 2 (ITS2) region was used to analyze rhizospheric soil samples from wild and reintroduced M. sinica. Thirteen phyla, 45 classes, 105 orders, 232 families, and 433 genera of fungi were detected. Basidiomycota and Ascomycota were dominant across all samples. The fungal community composition was similar between the wild and reintroduced rhizospheres, but the fungal taxa relative abundances differed. The fungal community richness was higher in the reintroduced rhizosphere than in the wild rhizosphere, but the diversity showed the opposite pattern. Soil nutrients and leaf litter significantly affected the fungal community composition and functional diversity. Here, the composition, structure, diversity, and ecological functions of the fungal communities in the rhizospheres of wild and reintroduced M. sinica were elucidated for the first time, laying a foundation for future research and endangered species protection.