Microbial Community Functional Diversity Research Articles

Soil Bacterial Community of Medicinal Plant Rhizosphere in a Mediterranean System

Several attempts have been made to evaluate the abundance and distribution of the bacterial community in the rhizosphere of medicinal plants. Many describe information based on an estimation of the community structure and the effects of plant cover in determining microbial community composition. The ability of plants to specifically shape their microbial community in general and medicinal plants in particular is largely unknown. With the arrival of molecular biology, understanding the microbial community’s composition, diversity, and function became possible. We hypothesized that microbial communities associated with medicinal shrubs would differ from each other. To test this hypothesis, we characterized the soil microbial composition under each of five Mediterranean medicinal plants, differentiated by their medicinal use and ecophysiological adaptation, namely, Salvia fruticosa, Pistacia lentiscus, Myrtus communis, Origanum syriacum, and Teucrium capitatum, and an open-space bare soil between the plants, inhabiting natural ecosystems characterized by similar climatic conditions typical of a Mediterranean environment. The results demonstrated the importance of plant ecophysiological adaptations, which play an important role in determining microbial community composition and functional diversity. The intensity of a plant’s response to its surroundings can have either positive or negative effects that will determine the microbial community composition and interactions among the belowground parts. A total of 11 phyla, 21 orders, and 409 genera were found in the soil rhizosphere in the vicinity of the four plants and open space samples. The distinguishing attributes of each shrub trigger and stimulate the microbial community’s rhizosphere. This results in distinct patterns of bacterial diversity and functionality between the different shrubs and the control. The rhizosphere bacterial community composition differed between the plants in a PERMANOVA test, but there was little difference in terms of phyla and order relative abundances. This study shows how five medicinal plants, coexisting in a common habitat, impact the bacterial community. The noticeable shift in bacterial composition further supports our discovery that root exudates effectively govern the makeup of soil bacterial communities.

Metagenomic analysis reveals gene taxonomic and functional diversity response to microplastics and cadmium in an agricultural soil

Both microplastics (MPs) and heavy metals are common soil pollutants and can interact to generate combined toxicity to soil ecosystems, but their impact on soil microbial communities (e.g., archaea and viruses) remains poorly studied. Here, metagenomic analysis was used to explore the response of soil microbiome in an agricultural soil exposed to MPs [i.e., polyethylene (PE), polystyrene (PS), and polylactic acid (PLA)] and/or Cd. Results showed that MPs had more profound effects on microbial community composition, diversity, and gene abundances when compared to Cd or their combination. Metagenomic analysis indicated that the gene taxonomic diversity and functional diversity of microbial communities varied with MPs type and dose. MPs affected the relative abundance of major microbial phyla and genera, while their coexistence with Cd influenced dominant fungi and viruses. Nitrogen-transforming and pathogenic genera, which were more sensitive to MPs variations, could serve as the indicative taxa for MPs contamination. High-dose PLA treatments (10%, w/w) not only elevated nitrogen metabolism and pathogenic genes, but also enriched copiotrophic microbes from the Proteobacteria phylum. Overall, MPs and Cd showed minimal interactions on soil microbial communities. This study highlights the microbial shifts due to co-occurring MPs and Cd, providing evidence for understanding their environmental risks.

Soil Microbial Community Structure and Functional Diversity Character of Abandoned Farmland in Minqin Oasis

To clarify the impact of the structure and function of soil microbial communities in the stage of abandoned farmland, three different stages of land abandoned in desert oasis areas were selected as the research objects. We used metagenomic sequencing technology to research soil microbial community structure and functional diversity characteristics of different stages of abandoned farmland. The results showed that there were significant differences in the relative abundance of the dominant phyla Actinobacteria, Proteobacteria, and Gemmatimonadetes in the soil of the three stages of returning farmland. Compared with that in the early stage of abandoned farmland, the later stage of abandoned farmland restoration increased the gene proportion involved in Quorum sensing, porphyrin and chlorophyll metabolism, pantothenate and CoA biosynthesis, and styrene degradation, and there was a significant difference in relative abundance (P<0.05), which indicated that different stages of abandoned farmland had changed the functional potential of the nutrient cycle and energy metabolism in soil microbial communities. The RDA results showed that EC, AK, and TN had a significant impact on the functional composition of soil microbes, and soil EC had the greatest impact on microbial functional composition. The results showed that different stages of abandoned farmland had a significant impact on the soil microbial community structure and functional composition. In the ecological restoration of abandoned farmland in Minqin Oasis, the sensitivity of microbial community structure and functional composition to soil restoration at different stages should be considered using comprehensive relevant indicators.

Functional diversity of microbial communities in herbaceous vegetation patches in coal mine heaps

AbstractCoal mine heaps represent unique novel environments, suitable for studying plant succession and its influence on the activity of microbes inhabiting the rhizosphere. Our aim was to verify if the functional diversity and catabolic activity of soil microorganisms would increase along with the plant succession from non‐vegetated and forbs‐dominated to grass‐dominated communities. The study was conducted on coal mine heaps located in Upper Silesia (Southern Poland), focusing on non‐vegetated patches, patches dominated by forbs–Tussilago farfara and Daucus carota (in the early stages of succession), and by grasses–Poa compressa and Calamagrostis epigejos (in later stages of primary succession). The catabolic activity and functional diversity of soil microbial communities were analyzed based on community‐level physiological profiles using BIOLOG EcoPlatesTM and the activity of dehydrogenase, alkaline phosphatase, acid phosphatase, and urease. Our results showed that spontaneous vegetation on coal mine heaps strongly affects the physicochemistry of the substrate and the functional diversity of soil microbial communities. Grasses' rhizosphere was hosting more active and functional diversified microbial communities, while non‐vegetated and T. farfara‐vegetated patches were accompanied by a reduced development of soil microbiota. Furthermore, grasses were mainly associated with a substantial delivery of plant litter to the substrate, providing a source of carbon for microorganisms.

Biomass and Functional Diversity of Microbial Communities in Catenas of Reserved and Arable Gray Soils and Chernozems

Biomass and Functional Diversity of Microbial Communities in Catenas of Reserved and Arable Gray Soils and Chernozems

Dominant nitrogen metabolisms of a warm, seasonally anoxic freshwater ecosystem revealed using genome resolved metatranscriptomics.

Nitrogen (N) availability is one of the principal drivers of primary productivity across aquatic ecosystems. However, the microbial communities and emergent metabolisms that govern N cycling in tropical lakes are both distinct from and poorly understood relative to those found in temperate lakes. This latitudinal difference is largely due to the warm (>20°C) temperatures of tropical lake anoxic hypolimnions (deepest portion of a stratified water column), which result in unique anaerobic metabolisms operating without the temperature constraints found in lakes at temperate latitudes. As such, tropical hypolimnions provide a platform for exploring microbial membership and functional diversity. To better understand N metabolism in warm anoxic waters, we combined measurements of geochemistry and water column thermophysical structure with genome-resolved metatranscriptomic analyses of the water column microbiome in Lake Yojoa, Honduras. We sampled above and below the oxycline in June 2021, when the water column was stratified, and again at the same depths and locations in January 2022, when the water column was mixed. We identified 335 different lineages and significantly different microbiome membership between seasons and, when stratified, between depths. Notably, nrfA (indicative of dissimilatory nitrate reduction to ammonium) was upregulated relative to other N metabolism genes in the June hypolimnion. This work highlights the taxonomic and functional diversity of microbial communities in warm and anoxic inland waters, providing insight into the contemporary microbial ecology of tropical ecosystems as well as inland waters at higher latitudes as water columns continue to warm in the face of global change.IMPORTANCEIn aquatic ecosystems where primary productivity is limited by nitrogen (N), whether continuously, seasonally, or in concert with additional nutrient limitations, increased inorganic N availability can reshape ecosystem structure and function, potentially resulting in eutrophication and even harmful algal blooms. Whereas microbial metabolic processes such as mineralization and dissimilatory nitrate reduction to ammonium increase inorganic N availability, denitrification removes bioavailable N from the ecosystem. Therefore, understanding these key microbial mechanisms is critical to the sustainable management and environmental stewardship of inland freshwater resources. This study identifies and characterizes these crucial metabolisms in a warm, seasonally anoxic ecosystem. Results are contextualized by an ecological understanding of the study system derived from a multi-year continuous monitoring effort. This unique data set is the first of its kind in this largely understudied ecosystem (tropical lakes) and also provides insight into microbiome function and associated taxa in warm, anoxic freshwaters.

Season shapes the functional diversity of microbial carbon metabolism in mangrove soils of Hainan Island, China

Carbon storage in mangroves is considered a natural solution to mitigate climate change as an essential coastal blue carbon ecosystem service for climate change. The magnitude of carbon storage in soils depends on the carbon metabolic activities of the microbial community, and these dynamics are subject to the influence of climate conditions, including seasonal changes. Despite mangroves being one of the world's highest in soil carbon density and carbon sequestration rates, our understanding of this aspect remains limited. Here, we investigated the seasonal changes in the carbon metabolic profile of microbial communities in mangrove soils along the seashore of the whole Hainan Island (with the highest diversity of mangrove species in China). There was a clear season dependence in the metabolic activity and functional diversity of mangrove soil microbial community on Hainan Island, showing the trend of the rainy season > the dry season. The carbon metabolic activity in the rainy season is three times higher than in the dry season. The season plays a critical role in shaping the carbon functional diversity of microbial communities, which that by changing biotic interactions and soil properties, particularly soil TN, NO2−–N, plant richness and mean DBH. This study provides important insights into comprehend the carbon metabolic functional diversity of microbial communities in mangrove soils and provides basic data support for predicting the blue carbon feedback of mangrove ecosystems to global climate change.

The impact of smash-ridge tillage on agronomic traits of tobacco plants, soil enzymatic activity, microbial community structure, and functional diversity

ABSTRACT Smash-ridge tillage is a novel cultivation technique that significantly influences the quality of arable land and crop yield. In this study, we employed high-throughput 16S rRNA sequencing and Biolog-ECO methods to systematically investigate the impact of smash-ridge tillage on soil microbial community structure and functional diversity. The results demonstrate that both ST30 and ST50 treatments significantly enhance the average plant height, average plant diameter, average fresh root weight, stem fresh weight, and leaf area of tobacco plants, with the ST50 treatment exhibiting superior performance. Furthermore, both ST30 and ST50 treatments exhibit significantly higher soil enzyme activity and microbial community diversity compared to the CK treatment. They also improve the soil microbial utilization of carbon sources. Additionally, the ST50-treated soil samples demonstrate 15 microbial functional pathways that exceed those of the CK and ST30 treatments. In conclusion, the Smash-ridge tillage treatment at a depth of 50 cm yields more favorable results. This study provides a theoretical foundation for enhancing soil quality in Smash-ridge tillage by elucidating the mechanisms through which it impacts soil microbial ecology.

Land abandonment transforms soil microbiome stability and functional profiles in apple orchards of the Chinese Losses Plateau

Land abandonment is considered an effective strategy for ecological restoration on a global scale. However, few studies have focused on how environmental heterogeneity associated with the age of land abandonment affects the assembly and potential functions of the soil microbial community. In the present study, we investigated the community assembly of soil bacteria and fungi as well as the stability of soil networks and their potential functions in the chronosequence of abandoned apple orchards. We elucidated that the Shannon diversity of bacteria and the richness of fungi increased as land abandonment progressed. In addition, land abandonment destabilized the microbial network stability but increased network complexity. Soil available nitrogen, total carbon, and moisture are the potentially important factors in shaping the soil microbial assembly. Importantly, we showed that the microbial community diversity and functional diversity presented a synchronization effect in response to the different stages of land abandonment. Furthermore, specific bacterial taxa related to carbon fixation, dissimilatory nitrate reduction, and organic phosphorus mineralization were significantly enriched during the early abandonment stage. Collectively, these results indicate that land abandonment significantly transformed soil microbiome assembly and functional adaptation during the restoration process. These findings provide valuable insights into the influence of ecological restoration on soil microbiome and ecosystem functions in arable areas.

The functional diversity of microbial communities in the multi-compartment biofilters of shrimp mariculture effluents using 16S rRNA metabarcoding

The functional diversity of microbial communities in the multi-compartment biofilters of shrimp mariculture effluents using 16S rRNA metabarcoding

Study of the structural and functional diversity of microbial communities in Uruguayan soils with respect to phosphorus phytoavailability: Doctoral thesis abstract

Phosphorus (P) is essential for plant growth; its excessive use as a fertilizer in agricultural intensification has negatively impacted the environment and the economy. Soil microorganisms play a key role in P cycling, mediating its phytoavailability through enzymatic mechanisms. In this thesis, we studied: a) the structural diversity of prokaryotic communities in five soil units with different parent materials and nutritional status; b) the functional profiles of these communities linked to P cycling and their relationship with soil physicochemical properties; c) the distribution and abundance of eight key enzymes of P cycling in grasslands of Uruguay and the world. Prokaryotic communities were studied using a metagenomic approach (16S rRNA gene and total metagenome). The main results were: a) Soil structure, nutrient content, and water retention capacity influence the composition of prokaryotic communities, composed mainly of Archaea, Firmicutes, Acidobacteria, Actinobacteria and Verrucomicrobia, with variations in their abundance according to soil type. b) Functional profiles of the communities were modeled by the same physicochemical properties as taxonomic diversity; functional diversity was lower than taxonomic diversity, suggesting functional redundancy. c) PhoD alkaline phosphatase was the most abundant and phylogenetically widely distributed enzyme, followed by Nsap-A and Nsap-C acid phosphatases. A strong association was found between the abundance and diversity of genes encoding these three enzymes and pH, maximum temperature and evapotranspiration. The results indicate that structural and functional prokaryotic diversity is influenced by soil physicochemical properties and environmental variables, making its understanding essential for the sustainable management of the P cycle in agroecosystems of the Campos biome.

Microbial metabolic activity in Amazon floodplain forest and agricultural soils.

Microorganisms play an essential role in ecosystem functions. An increasingly used method for conducting functional analyses of a soil microbial community is based on the physiological profile at the community level. This method allows the metabolic capacity of microorganisms to be assessed based on patterns of carbon consumption and derived indices. In the present study, the functional diversity of microbial communities was assessed in soils from seasonally flooded-forest (FOR) and -traditional farming systems (TFS) in Amazonian floodplains flooded with black, clear, and white water. The soils of the Amazon floodplains showed differences in the metabolic activity of their microbial communities, with a general trend in activity level of clear water floodplain > black water floodplain > white water floodplain. The redundancy analysis (RDA) indicated that soil moisture (flood pulse) was the most important environmental parameter in determining the metabolic activity of the soil microbial communities in the black, clear, and white floodplains. In addition, the variance partitioning analysis (VPA) indicated that the microbial metabolic activity of the soil was more influenced by water type (41.72%) than by seasonality (19.55%) and land use type (15.28%). The soil microbiota of the white water floodplain was different from that of the clear water and black water floodplains in terms of metabolic richness, as the white water floodplain was mainly influenced by the low substrate use during the non-flooded period. Taken together, the results show the importance of considering soils under the influence of flood pulses, water types, and land use as environmental factors when recognizing functional diversity and ecosystem functioning in Amazonian floodplains.

Metagenomic analysis reveals taxonomic and functional diversity of microbial communities on the deteriorated wall paintings of Qinling Tomb in the Southern Tang Dynasty, China

The microbial colonization on ancient murals attracts more and more attention since the threaten by microorganisms was first reported in Lascaux, Spain. However, the biodeterioration or biodegradation of mural paintings resulted by microorganisms is not clear yet. Especially the biological function of microbial communities in different conditions remained largely unaddressed. The two mausoleums of the Southern Tang Dynasty are the largest group of emperor mausoleums during the Five Dynasties and Ten Kingdoms period in China, which are of great significance to the study of the architecture, imperial mausoleum systems and art in the Tang and Song Dynasties. To make clear the species composition and metabolic functions of different microbial communities (MID and BK), we analyzed the samples from the wall paintings in one of the two mausoleums of the Southern Tang Dynasty with metagenomics method. The result showed totally 55 phyla and 1729 genera were detected in the mural paintings. The two microbial community structure were similar with the dominance of Proteobacteria, Actinobacteria and Cyanobacteria. However, the species abundance presented a significant difference between two communities at genus level --- MID is Lysobacter, Luteimonas are predominant in MID while Sphingomonas and Streptomyces are popular in BK, which is partially attributed to the different substrate materials of murals. As a result, the two communities presented the different metabolic patterns that MID community was mainly participated in the formation of biofilm as well as the degradation of exogenous pollutants while the BK was predominantly related to the photosynthesis process and biosynthesis of secondary metabolites. Taken together, these findings indicated the effect of environmental factor on the taxonomic composition and functional diversity of the microbial populations. The installation of artificial lighting needs to be considered carefully in the future protection of cultural relics.

How Important Are the Relations between Vegetation Diversity and Bacterial Functional Diversity for the Functioning of Novel Ecosystems?

Understanding ecosystem development of post-mining areas requires observing the development of the plant and microbial communities. It is widely known that mutual interaction is important for both of these groups, and both benefit significantly. The aim of this study was to broaden the knowledge about the relation between the vegetation and functional diversity of bacterial communities in novel ecosystems of post-mining areas and to discuss the potential applicability of methods of studies of bacterial functional diversity in these ecosystems with special attention paid to the BIOLOG method. The functional diversity of microbial communities of five types of microhabitats of post-coal mining heap (Upper Silesia, Poland) was studied using the BIOLOG method. Four of them were covered by spontaneously developed vegetation (two dominated by grasses Calamagrostis epigejos and Poa compressa and two others by dicotyledonous species Daucus carota and Tussilago farfara). The results obtained for vegetated microhabitats were compared with the diversity of microbial communities from non-vegetated types of microhabitat. Our study confirmed that microbial functional diversity measured by the summed area under the curve for all substrates, the richness index, the Shannon-Wiener index and the evenness index mirrors aboveground vegetation diversity. All of these measures differ, especially between non-vegetated patches and grassland patches dominated by C. epigejos and P. compressa.

Community Level Physiological Profiling of Microbial Communities Influencing Mine Spoil Genesis in Chronosequence Coal Mine Overburden Spoil

Ecological restoration through mine spoil genesis should be dogmatic and the strategies involved a holistic approach, which emphasizes the role of microbial community composition that varies in accordance with the physiological and nutritional status of mine spoil profiles. This is because the patterns observed aboveground is being driven by the belowground diversity and processes. Thus, the relationship between microbial community structure and mine spoil genesis in chronosequence coal mine spoil has attracted considerable research attention. The occurrence of higher microbial diversity and difficulties in culturing microbes necessitate the use of a culture-independent approach through community-level physiological profiling based on the patterns of carbon source utilization using BIOLOG Ecoplate and thereby the functional diversity of microbial communities in different age series coal mine spoil was determined. The average well-color development exhibited an increasing trend with a minimum in OB0 (0.0640) and a maximum in OB15 (0.5060) over time. The patterns of substrate utilization (carbohydrates, carboxylic and ketonic acids, amino acids, polymers, amines, and amides) reflect the shift in microbial community composition in different age series coal mine spoil over time. Gradual increase in species richness and Shannon diversity index with the increase in age of mine spoil substantiated relatively higher microbial diversity reflecting the sign of mine spoil genesis. Principal component analysis and redundancy analysis based on the differential patterns of substrate utilization discriminate different age series coal mine spoil into independent clusters, which evaluated the broad-scale patterns of microbial community dynamics influencing the pace and progress of mine spoil genesis.

Effects of Straw Returning on Soil Chemical Properties and Microbial Community Diversity under the Rice-Crayfish Integrated System

This study presents an investigation of soil chemical properties and microbial community diversity by Biolog ECO analysis in a seven-year field experiment using winter flooded fallow + no straw returning (W), winter flooded fallow + straw returning (WS), and winter flooded fallow + straw returning + crayfish farming (WSC) at soil depths of 0–10 cm and 10–20 cm. Compared with the WS treatment, the WSC treatment had significantly higher total organic carbon (TOC) content in the 0–10 cm layer as well as greater available nitrogen (AN) and total nitrogen (TN) contents and acid phosphatase and sucrase activities in the 10–20 cm layer, while the pH value, total reducing substances, and Fe2+ content in the 0–20 cm layer were considerably lower. The WSC treatment improved the microbial species abundance in the 10–20 cm layer and the utilization rate of carbon sources in the 0–20 cm layer compared with the WS treatment. The soil microbial species abundance, microbial community diversity, and utilization rate of carbon sources in all of the layers examined were significantly higher in the WSC treatment than in the W treatment. The results indicate that straw returning under the rice-crayfish integrated system improves the contents of TOC, TN, and AN, decreases reducing substances properties, increases acid phosphatase and sucrase activities, and improves microbial community functional diversity, thereby contributing to the improvement of soil quality and the long-term sustainable development of the rice-crayfish integrated system.

Effects of Nitrogen Addition on Soil Microbial Functional Diversity and Extracellular Enzyme Activities in Greenhouse Cucumber Cultivation

Greenhouses, commonly used for vegetable production, are experiencing large nitrogen (N) inputs in North China, which leads to soil acidification, increases soil N availability, and affects microbial community structure and composition. However, it remains unclear how N enrichment influences soil microbial functional activities in this region. In this study, we conducted a two-year pot experiment in a greenhouse to evaluate the effects of four different rates of N addition (0, 334, 668, and 1002 kg N ha−1 year−1) on cucumber soil properties, extracellular enzyme activities, and community level physiological profiles (CLPP). We found that high-N addition (1002 kg N ha−1) caused a massive accumulation of inorganic nitrogen and soil acidification, which was not beneficial to soil microbial activities. The color development (AWCD) values for the metabolism of microbial carbon sources and the activities of soil extracellular enzymes also showed a significant decrease in high N(N3) treatment. Additionally, the activity of leucine aminopeptidase (LAP) and polyphenol oxidase (PPO) of N3 decreased by 36% and 50% compared to the N0 and could be a good predictor for microbial functional diversity and microbial biomass carbon (MBC). Structural equation modeling (SEM) confirmed that the reduction of microbial functional diversity is mainly coregulated by the decline of soil pH and the change of cucumber BGB (belowground biomass) resulting from soil C and N imbalance. Overall, excessive N-fertilizer amendment can be more dangerous to microbial community functional diversity, especially for carbohydrate utilization which adversely affects cucumber yield in current intensive management.

Effects of Insect-Resistant Maize 2A-7 Expressing mCry1Ab and mCry2Ab on the Soil Ecosystem.

Transgenic maize 2A-7 expressing mCry1Ab and mCry2Ab has excellent resistance to lepidopteran pests. Previous studies have investigated the effects of several Bacillus thuringiensis (Bt) proteins on the soil. However, the effects of artificially modified Bt proteins on soil ecosystems are still unclear. To evaluate the effects of transgenic maize 2A-7 on soil, the physicochemical properties, enzyme activities and functional diversities of the microbial communities in rhizosphere soils from 2A-7 and its near-isogenic non-transgenic control Dongdan 6531 were analyzed at different developmental stages under field conditions. The alteration of six physicochemical properties (pH, total nitrogen, total phosphorus, organic matter, available phosphorus and alkali-hydrolyzed nitrogen) and six functional enzymes (catalase, alkaline phosphatase, sucrase, acid phosphatase, urease and alkaline protease) activities in the rhizosphere soils between the two maize cultivars were drastically correlated with plant growth stage, but not affected by the artificially modified Bt transgenes. An analysis of time-course Biolog data revealed that the functional diversity of microbial communities in the rhizosphere soil of 2A-7 and its control were similar at each developmental stage. The results suggest that transgenic maize 2A-7 has no significant impact on the soil ecosystem and provide valuable information on scientific safety assessments of 2A-7 and its commercial applications.

Functional Diversity of Microbial Communities in the Soybean (Glycine max L.) Rhizosphere from Free State, South Africa.

The plant microbiome is involved in enhancing nutrient acquisition, plant growth, stress tolerance, and reducing chemical inputs. The identification of microbial functional diversity offers the chance to evaluate and engineer them for various agricultural processes. Using a shotgun metagenomics technique, this study examined the functional diversity and metabolic potentials of microbial communities in the rhizosphere of soybean genotype link 678. The dominant genera are Geobacter, Nitrobacter, Burkholderia, Candidatus, Bradyrhizobium and Streptomyces. Twenty-one functional categories were present, with fourteen of the functions being dominant in all samples. The dominant functions include carbohydrates, fatty acids, lipids and isoprenoids, amino acids and derivatives, sulfur metabolism, and nitrogen metabolism. A Kruskal–Wallis test was used to test samples’ diversity differences. There was a significant difference in the alpha diversity. ANOSIM was used to analyze the similarities of the samples and there were significant differences between the samples. Phosphorus had the highest contribution of 64.3% and was more prominent among the soil properties that influence the functional diversity of the samples. Given the functional groups reported in this study, soil characteristics impact the functional role of the rhizospheric microbiome of soybean.

Microbial Community, Metabolic Potential and Seasonality of Endosphere Microbiota Associated with Leaves of the Bioenergy Tree Paulownia elongata × fortunei.

The microbial structure and metabolic function of plant-associated endophytes play a key role in the ecology of various environments, including trees. Here, the structure and functional profiles of the endophytic bacterial community, associated with Paulownia elongata × fortunei, in correlation with seasonality, were evaluated using Biolog EcoPlates. Biolog EcoPlates was used to analyse the functional diversity of the microbiome. The total communities of leaf endophyte communities were investigated using 16S rRNA V5–V7 region amplicon deep sequencing via Illumina MiSeq. Community level physiological profiling (CLPP) analysis by the Biolog EcoPlate™ assay revealed that the carboxylic acids (19.67–36.18%) and amino acids (23.95–35.66%) were preferred by all by all communities, whereas amines and amides (0.38–9.46%) were least used. Seasonal differences in substrate use were also found. Based on the sequencing data, mainly phyla Proteobacteria (18.4–97.1%) and Actinobacteria (2.29–78.7%) were identified. A core microbiome could be found in leaf-associated endophytic communities in trees growing in different locations. This work demonstrates the application of Biolog EcoPlates in studies of the functional diversity of microbial communities in a niche other than soil and shows how it can be applied to the functional analyses of endomicrobiomes. This research can contribute to the popularisation of Biolog EcoPlates for the functional analysis of the endomicrobiome. This study confirms that the analysis of the structure and function of the plant endophytic microbiome plays a key role in the health control and the development of management strategies on bioenergy tree plantations.