FIGURE 2 - available via license: Creative Commons Attribution 4.0 International
Content may be subject to copyright.
| NMDS illustrating the phyllosphere bacterial community; separate clusters of bacterial communities are evident for (A) the epiphytic (red) and the endophytic (blue) bacterial communities from leaves sampled from south side canopy areas; and (B) unique clusters of endophytic bacterial communities observed in A. raddiana (blue) and A. tortilis leaves.
Source publication
Background: The evolutionary relationships between plants and their microbiomes are of high importance to the survival of plants in general and even more in extreme conditions. Changes in the plant's microbiome can affect plant development, growth, fitness, and health. Along the arid Arava, southern Israel, acacia trees ( Acacia raddiana and Acacia...
Contexts in source publication
Context 1
... total of 139 acacia leaf samples [two tree species × two replicate trees from each species × 3 canopy locations for epiphytes (but only the south canopy for endophytes) × 9 months] were collected for both epiphytic and endophytic microbial communities ( Supplementary Table 1; notice that a total of seven samples were lost during sample processing before sequencing) and sequenced for their 16S rRNA genes using our five different primer sets (Supplementary Table 2). The average sequence number per each primer set varied significantly for the different regions of amplification (Supplementary Table 2). Results showed that the third primer set (F649 and R889) obtained the highest number of raw sequences with an average raw sequence number of 38,683 ± 18,723; thus, we based all further analysis on the F649-R889 primer set. ...
Context 2
... compare the diversities of epiphytic and endophytic bacterial communities extracted from leaf samples, acacia samples from south-facing canopies were analyzed and plotted using NMDS, based on the Bray-Curtis distance matrix (Figure 2). The NMDS showed two separate clusters of epiphytic and endophytic bacterial communities, statistical analysis Using PERMANOVA found endophytic and epiphytic microbial communities to be significantly different (p = 0.001; Figure 2A). ...
Context 3
... compare the diversities of epiphytic and endophytic bacterial communities extracted from leaf samples, acacia samples from south-facing canopies were analyzed and plotted using NMDS, based on the Bray-Curtis distance matrix (Figure 2). The NMDS showed two separate clusters of epiphytic and endophytic bacterial communities, statistical analysis Using PERMANOVA found endophytic and epiphytic microbial communities to be significantly different (p = 0.001; Figure 2A). While the epiphytic bacterial communities from the two acacia species (A. ...
Context 4
... the epiphytic bacterial communities from the two acacia species (A. raddiana and A. tortilis) did not demonstrate separate clusters (p = 0.134, Table 2, Figure 2A), the endophytic bacterial communities were found to be significantly different for both acacia species (p = 0.021, Table 3, Figure 2B). To illustrate these differences, we plotted the bacterial phylum with more than 5% of the total community composition (Figure 3) and performed Tukey test of significance on the log-transformed abundances to normalize the variance. ...
Context 5
... the epiphytic bacterial communities from the two acacia species (A. raddiana and A. tortilis) did not demonstrate separate clusters (p = 0.134, Table 2, Figure 2A), the endophytic bacterial communities were found to be significantly different for both acacia species (p = 0.021, Table 3, Figure 2B). To illustrate these differences, we plotted the bacterial phylum with more than 5% of the total community composition (Figure 3) and performed Tukey test of significance on the log-transformed abundances to normalize the variance. ...
Context 6
... terms of the overall observed number of OTUs, Chao1, Simpson, and Shannon-Wiener diversity indices, the diversity of the epiphytic bacterial community was shown to be double that of its endophytic bacterial community counterpart ( Table 1). While the average number of classified bacteria sequences for epiphytes was slightly higher (16,752) compared to endophytic (14,857) bacterial communities, the sequence number in each sample had no effect on the obtained diversity indices (Supplementary Figure 2). The higher abundance and richer microbial communities in epiphytes compared to endophytes were also observed in young and mature leaves of Origanum vulgare, where the total number of colony-forming units (CFUs) of epiphytic bacterial communities (5.0 ± 0.2) was more than double the CFUs of the associated endophytic communities (1.8 ± 0.1) ( Pontonio et al., 2018). ...
Context 7
... results demonstrate that the epiphytic and endophytic bacterial communities are significantly unique (Figures 2A, 3, Supplementary Figure 8). We also found that the endophytic (but not the epiphytic) bacteria communities differed between the two acacia species (Figures 2A,B, Tables 2, 3, Supplementary Figures 6B, 8), with each host being associated with specific endophytic communities. ...
Context 8
... results demonstrate that the epiphytic and endophytic bacterial communities are significantly unique (Figures 2A, 3, Supplementary Figure 8). We also found that the endophytic (but not the epiphytic) bacteria communities differed between the two acacia species (Figures 2A,B, Tables 2, 3, Supplementary Figures 6B, 8), with each host being associated with specific endophytic communities. In fact, many studies have indicated that the composition and abundance of endophytes in plants are synergistically determined by plant genotype and environmental factors (Terhonen et al., 2019). ...
Context 9
... highest diversity was seen in older leaves, leaves that have been on the tree the longest time (i.e., June and July, Supplementary Figure 3). When we statistically checked the effect of tree phylogeny in both epiphytic and endophytic microbial community, we found endophytes but not epiphytes to be affected by tree phenology (leaves shedding period) (Tables 2, 3; Figure 4B, Supplementary Figures 6A, 7A). ...
Citations
... Colonization of plants by microorganisms is a widely recognized phenomenon, both aboveground in the phyllosphere and belowground in the rhizosphere [6,7]. However, studies examining the bacterial communities of epiphyte plants have been conducted under adverse environmental conditions and have primarily focused on specific plant species [6]. ...
... Colonization of plants by microorganisms is a widely recognized phenomenon, both aboveground in the phyllosphere and belowground in the rhizosphere [6,7]. However, studies examining the bacterial communities of epiphyte plants have been conducted under adverse environmental conditions and have primarily focused on specific plant species [6]. These studies revealed differences in microbial community composition between plant compartments, species, temporal changes, and biogeographic patterns [8]. ...
Tillandsia recurvata is an epiphytic plant commonly found in tropical regions and colonizes tree trunks, fences, and power wires. This plant plays an important role in interacting with trees, sharing microorganisms, and performing specific functions in the process of tree colonization. The objective of this study was to evaluate and compare the microbiomes of T. recurvata collected from two different locations (trees and fences) and two plant tissues (leaves and roots). The hypothesis of this study was that the microbiome of T. recurvata is composed of microorganisms that would provide nutritional support to compensate for the lack of nutrients in a particular growth support. The results showed significant differences in microbial diversity between trees and fences, with trees exhibiting higher richness and more complex microbial networks. Proteobacteria was the most prevalent bacterial phylum, with Actinobacteria and Sphingomonas also playing key roles in nitrogen fixation and plant growth. Fungal communities were similar across locations, with Ascomycota and Basidiomycota being predominant, but Paraconiothyrium and Nigrospora showed significant differences in abundance between trees and fences. Functional analysis indicated similar metabolic profiles across leaf and root samples, with key functions for T. recurvata including carbohydrate and amino acid metabolism, stress control, and biofertilization.
... Notably, Bromeliaceae represents the only epiphytic lineage within the order Poales and comprises a highly diverse group of plants that encompasses both grasses and sedges [4]. Colonization of plants by microorganisms is a widely recognized phenomenon, both aboveground in the phyllosphere and belowground in the rhizosphere [5,6]. However, studies examining the bacterial communities of epiphyte plants have been conducted under adverse environmental conditions and have primarily focused on speci c plant species [5]. ...
... Colonization of plants by microorganisms is a widely recognized phenomenon, both aboveground in the phyllosphere and belowground in the rhizosphere [5,6]. However, studies examining the bacterial communities of epiphyte plants have been conducted under adverse environmental conditions and have primarily focused on speci c plant species [5]. These studies revealed differences in microbial community composition between plant compartments, species, temporal changes, and biogeographic patterns [7]. ...
Tillandsia recurvata is an epiphytic plant commonly found in tropical regions and colonizes tree trunks, fences, and power wires. This plant plays an important role in interacting with trees, sharing microorganisms, and performing specific functions in the process of tree colonization. The objective of this study was to evaluate and compare the microbiomes of T. recurvata collected from two different locations (trees and fences) and two plant tissues (leaves and roots). The hypothesis of this study was that the microbiome of plants on the fence is composed of microorganisms that would provide nutritional support to compensate for the lack of nutrients in a particular area. The results showed significant differences in microbial diversity between trees and fences, with trees exhibiting higher richness and more complex microbial networks. Proteobacteria was the most prevalent bacterial phylum, with Actinobacteria and Sphingomonas also playing key roles in nitrogen fixation and plant growth. Fungal communities were similar across locations, with Ascomycota and Basidiomycota being predominant, but Paraconiothyrium and Nigrospora showed significant differences in abundance between trees and fences. Functional analysis indicated similar metabolic profiles across leaf and root samples, with key functions including carbohydrate and amino acid metabolism, stress control, and biofertilization.
... In the realm of studies on endophytic microbial diversity, most researchers posit that the diversity of endophytes during winter tends to decrease due to factors such as low temperatures and reduced solar radiation [110]. However, the diversity of both endophytic bacteria and endophytic fungi in Actinidia arguta is paradoxically highest during winter. ...
The seasonal changes in environmental conditions can alter the growth states of host plants, thereby affecting the living environment of endophytes and forming different endophytic communities. This study employs Illumina MiSeq next-generation sequencing to analyze the 16SrRNA and ITS rDNA of endophytes in 24 samples of Actinidia arguta stem tissues across different seasons. The results revealed a high richness and diversity of endophytes in Actinidia arguta, with significant seasonal variations in microbial community richness. This study identified 897 genera across 36 phyla for bacteria and 251 genera across 8 phyla for fungi. Notably, 69 bacterial genera and 19 fungal genera significantly contributed to the differences in community structure across seasons. A distinctive feature of coexistence in the endophytic community, both specific and conservative across different seasons, was observed. The bacterial community in winter demonstrated significantly higher richness and diversity compared to the other seasons. Environmental factors likely influence the optimal timing for endophyte colonization. Solar radiation, temperature, precipitation, and relative humidity significantly impact the diversity of endophytic bacteria and fungi. In addition, seasonal variations show significant differences in the nutritional modes of fungal endophytes and the degradation, ligninolysis, and ureolysis functions of bacterial endophytes. This study elucidates the potential role of endophytes in assisting Actinidia arguta in adapting to seasonal changes and provides a theoretical basis for further exploration of functional microbial strains.
... There was a distinct discrepancy between phyllosphere bacterial communities across the different site regions, clearly indicating that climatic variables can influence beta-diversity. On the whole, the phyllosphere bacterial diversity was markedly associated with the two sets of climatic factors, implying that temperature and precipitation variables are likely important for shaping the phyllosphere epiphytic bacterial community of woody plants (Al Ashhab et al., 2021). ...
Introduction
As an ephemeral and oligotrophic environment, the phyllosphere harbors many highly diverse microorganisms. Importantly, it is known that their colonization of plant leaf surfaces is considerably influenced by a few abiotic factors related to climatic conditions. Yet how the dynamics of phyllosphere bacterial community assembly are shaped by detailed climatological elements, such as various bioclimatic variables, remains poorly understood.
Methods
Using high-throughput 16S rRNA gene amplicon sequencing technology, we analyzed the bacterial communities inhabiting the leaf surfaces of an oilseed tree, yellowhorn (Xanthoceras sorbifolium), grown at four sites (Yinchuan, Otogqianqi, Tongliao, and Zhangwu) whose climatic status differs in northern China.
Results and Discussion
We found that the yellowhorn phyllosphere’s bacterial community was generally dominated by four phyla: Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes. Nevertheless, bacterial community composition differed significantly among the four sampled site regions, indicating the possible impact of climatological factors upon the phyllosphere microbiome. Interestingly, we also noted that the α-diversities of phyllosphere microbiota showed strong positive or negative correlation with 13 bioclimatic factors (including 7 precipitation factors and 6 temperature factors). Furthermore, the relative abundances of 55 amplicon sequence variants (ASVs), including three ASVs representing two keystone taxa (the genera Curtobacterium and Streptomyces), exhibited significant yet contrary responses to the precipitation and temperature climatic variables. That pattern was consistent with all ASVs’ trends of possessing opposite correlations to those two parameter classes. In addition, the total number of links and nodes, which conveys community network complexity, increased with rising values of most temperature variables. Besides that, remarkably positive relevance was found between average clustering coefficient and most precipitation variables. Altogether, these results suggest the yellowhorn phyllosphere bacterial community is capable of responding to variation in rainfall and temperature regimes in distinctive ways.
... Precipitation is also an important reservoir of phyllospheric microorganisms [49]. (3) Dust may be an important reservoir of the phyllosphere microbial community [50], and climatic variables such as precipitation and wind speed can affect dust. (4) Climate change in the historical period reshaped the spatial distribution pattern of vegetation. ...
... Phyllosphere iron, phyllosphere manganese, chlorophyll b and soil organic carbon jointly dominate the phyllosphere microbial community structure of rice [67]. In addition, temporal variation (seasonal variation and sampling month) dominate the community structure of acacia epiphytic bacteria [50]. (2) The relationship between phyllosphere microbial community structure and individual influencing factors is still controversial. ...
... Up to now, based on the temperature gradient formed by geographical location (altitude gradient, etc.) or seasonal changes [1,40,50,80,81] and warming experiments [82][83][84], some scientific research results with theoretical value and practical guiding significance have been achieved on the impact of climate warming on the structure of the phyllosphere microbial community. For example, the phyllosphere microbial community structure of different dimensions (species and phylogeny, etc.) have different responses to climate warming [85]. ...
Phyllosphere microorganisms are not only an important part of plants, but also an important part of microorganisms. In this review, the function of phyllosphere microorganisms, the assembly mechanism of phyllosphere microorganisms, the driving factors of phyllosphere microbial com-munity structure, and the effects of climate warming on phyllosphere microbial community structure were reviewed. Generally, phyllosphere microorganisms have a variety of functions (e.g., fixing nitrogen, promoting plant growth). Although selection and dispersal processes together regulate the assembly of phyllospheric microbial communities, which one of the ecological pro-cesses is dominant and how external disturbances alter the relative contributions of each ecological process remains controversial. Abiotic factors (e.g., climatic conditions, geographical location and physical and chemical properties of soil), and biological factors (e.g., phyllosphere morphological structure, physiological and biochemical characteristics, plant species and varieties) can affect phyllosphere microbial community structure. However, it is still controversial on the predominated factors in affecting phyllosphere microbial community structure. Moreover, how climate warming affects the phyllosphere microbial community structure and its driving mechanism have not been fully resolved, and further relevant studies are needed.
... Leaf micr otopogr a phy may, ho w e v er, alle viate some of these stresses by providing bacteria with microshelters at the base of their trichomes (Kusstatscher et al. 2020 ) and around leaf veins or stomata (Yan et al. 2022 ). Leaf endophytes can comparativ el y be influenced by environmental conditions experienced by the plant such as heating or soil water availability (Carper et al. 2018, Al Ashhab et al. 2021, but these stresses are likely not reaching the same intensity as for epiphytes. ...
... Alpha diversity of epiphytic communities was much higher than in the endophytic communities . T his result is coherent with bacterial comm unity div ersity r eported acr oss leaf compartments in other ecosystems (Mina et al. 2020, Yao et al. 2020, Al Ashhab et al. 2021. A gr eater envir onmental v ariability at the leaf surface than the interior of the leaf could explain these differences (Vorholt 2012 ). ...
Bacteria from the leaf surface and the leaf tissue have been attributed with several beneficial properties for their plant host. Though physically connected, the microbial ecology of these compartments has mostly been studied separately such that we lack an integrated understanding of the processes shaping their assembly. We sampled leaf epiphytes and endophytes from the same individuals of sugar maple across the northern portion of its range to evaluate if their community composition was driven by similar processes within and across populations differing in plant traits and overall abiotic environment. Leaf compartment explained most of the variation in community diversity and composition across samples. Leaf epiphytic communities were driven more by host and site characteristics than endophytic communities, whose community composition was more idiosyncratic across samples. Our results suggest a greater importance of priority effects and opportunistic colonization in driving community assembly of leaf endophytes. Understanding the comparative assembly of bacterial communities at the surface and inside plant leaves may be particularly useful for leveraging their respective potential for improving the health of plants in natural and anthropized ecosystems.
... Phyllosphere microbiomes, including the epibiotic and endophytic microbial communities, can be impacted by various abiotic and biotic factors, including plant host genetics (e.g., species and genotype), plant traits (e.g., leaf chemical composition), management (e.g., chemical applications), seasonality, and geographic location (22)(23)(24)(25)(26). Core microbial members commonly present across multiple plant species and geologic areas may reflect their indispensable interactions with plants (27,28). ...
... Phyllosphere microbiomes, including the epibiotic and endophytic microbial communities, can be impacted by various abiotic and biotic factors, including plant host genetics (e.g., species and genotype), plant traits (e.g., leaf chemical composition), management (e.g., chemical applications), seasonality, and geographic location (22)(23)(24)(25)(26). Core microbial members commonly present across multiple plant species and geologic areas may reflect their indispensable interactions with plants (27,28). In contrast to the core microbes, indicator microbial species found abundantly in particular plants may reflect specific associations and adaptations of certain plant-microbe pairs (25). Overall, by affecting plant traits and plant-microbial interactions, phyllosphere microbiomes can have a direct impact on and potential application for use in agricultural and environmental health (27,29,30). ...
Grasses harbor diverse fungi, including some that produce mycotoxins or other secondary metabolites. Recently, Florida cattle farmers reported cattle illness, while the cattle were grazing on warm-season grass pastures, that was not attributable to common causes, such as nutritional imbalances or nitrate toxicity. To understand correlations between grass mycobiome and mycotoxin production, we investigated the mycobiomes associated with five prominent, perennial forage and weed grasses [Paspalum notatum Flügge, Cynodon dactylon (L.) Pers., Paspalum nicorae Parodi, Sporobolus indicus (L.) R. Br., and Andropogon virginicus (L.)] collected from six Florida pastures actively grazed by livestock. Black fungal stromata of Myriogenospora and Balansia were observed on P. notatum and S. indicus leaves and were investigated. High-throughput amplicon sequencing was applied to delineate leaf mycobiomes. Mycotoxins from P. notatum leaves were inspected using liquid chromatography-mass spectrometry (LC-MS/MS). Grass species, cultivars, and geographic localities interactively affected fungal community assemblies of asymptomatic leaves. Among the grass species, the greatest fungal richness was detected in the weed S. indicus. The black fungal structures of P. notatum leaves were dominated by the genus Myriogenospora, while those of S. indicus were codominated by the genus Balansia and a hypermycoparasitic fungus of the genus Clonostachys. When comparing mycotoxins detected in P. notatum leaves with and without M. atramentosa, emodin, an anthraquinone, was the only compound which was significantly different (P < 0.05). Understanding the leaf mycobiome and the mycotoxins it may produce in warm-season grasses has important implications for how these associations lead to secondary metabolite production and their subsequent impact on animal health. IMPORTANCE The leaf mycobiome of forage grasses can have a major impact on their mycotoxin contents of forage and subsequently affect livestock health. Despite the importance of the cattle industry in warm-climate regions, such as Florida, studies have been primarily limited to temperate forage systems. Our study provides a holistic view of leaf fungi considering epibiotic, endophytic, and hypermycoparasitic associations with five perennial, warm-season forage and weed grasses. We highlight that plant identity and geographic location interactively affect leaf fungal community composition. Yeasts appeared to be an overlooked fungal group in healthy forage mycobiomes. Furthermore, we detected high emodin quantities in the leaves of a widely planted forage species (P. notatum) whenever epibiotic fungi occurred. Our study demonstrated the importance of identifying fungal communities, ecological roles, and secondary metabolites in perennial, warm-season grasses and their potential for interfering with livestock health.
... We also found that not all QA samples gathered together (Figure 2a), possibly because Lachnum was the dominant genus of QC with high relative abundance, which was similar to the subsamples QA1, QA2 and QA3. In addition to being influenced by plant species and nearby plants, the microbiome can also be influenced by as soil [70,71] and climatic factors [72]. From our results, the abundance of Lachnum correlated positively with soil pH, SEN, SAK, SOM and T (Figure 3a). ...
Host plants are known to determine the distribution and development of ectomycorrhizal fungi such as Tricholoma matsutake; however, we found that the fruit body distribution of T. matsutake was different in Quercus mongolica pure or mixed forests. To clarify the fungal and other microbial composition rules of host plants, ectomycorrhizal root tip samples of Q. mongolica mixed with different plants were selected for study. By using high-throughput sequencing, we obtained 5229 fungal and 38,834 bacterial amplicon sequence variants (ASVs) as determined by internally transcribed spacer ribosomal RNA (ITS rRNA) and 16S ribosomal RNA (16S rRNA) sequencing via the Illumina NovaSeq platform. Among the neighboring plants, there were no significant differences in fungal or bacterial alpha diversity, but there was a significant difference (p < 0.05) in ectomycorrhizal alpha diversity. The fungal, bacterial and ectomycorrhizal fungal communities in the ectomycorrhizosphere of Q. mongolica all showed differences in beta diversity and species composition. In addition, the physical and chemical properties of the soil and the relationships among species could affect the relative abundance of fungi, bacteria and ectomycorrhizal fungi, but the soil microbial pool had little effect on microbial composition. Using PICRUSt2, some significantly up-regulated (p < 0.05) metabolic functions in ectomycorrrhizospheric microbial communities were predicted, which would be an interesting research field for ectomycorrhizal microecology.
... Among the bacterial community, Bacillaceae was the most abundant family. The earlier studies also showed the predominance of Bacillaceae and Moraxellaceae under the phyla Firmicutes and Proteobacteria in the phyllospheric endomicrobiome of different plants similar to the present observations [38][39][40]. ...
... Plant-associated habitats are undulating due to the involvement of many factors in the dynamic environments that affect the species compositions in the microbial communities. Shen and Fulthorpe [39] and Ou et al. [8] reported that the endophytic bacterial community becomes more in abundance and diversity during the summer and rainy seasons and again quenched during winter and unfavourable conditions. Similarly, in this study, the samples collected in the pre-flowering season of mango (summer and rainy seasons) showed the highest beta diversity and dissemination of endophytic bacterial communities between the three plants and the alpha diversity, which denotes the diversity of bacteria, were shown higher in the sample of the post-flowering season of mango plants (late winter). ...
... The majority of the Bacillus spp., present in the host plants, play an important role as a potent plant growth promoter and biocontrol agent and protect the host plant from phytopathogens [2,3]. Therefore, the specific role of Bacillus and other genera on the plant system might be that they promote better health and resist phytopathogens [39]. ...
The study of community composition and community structure is important to know the ecological behaviour and community dynamics of the participating species and to understand the molecular interplay that lies between them. The community diversity greatly lies in the physiological status of the host and the environmental factors. The present study aims to explore the endophytic bacterial communities and their dynamics in the pre-flowering and post-flowering seasons in the horticulturally important Mango (Mangifera indica L.) and its hemiparasites: Loranthus parasiticus (L.) Marr. and Macrosolen colchinchinensis (Lour.) Tiegh. through a metagenomic approach using the sequence of V3 region of 16S rRNA gene. The genera Bacillus, Acinetobacter and Corynebacterium, under the phyla Firmicutes, Proteobacteria and Actinobacteria, respectively, were found to be the most abundant genera present in mango and its hemiparasites. It was found that during the post-flowering season, the twigs and leaves of mango had lesser endophytes than in other seasons while the alpha-diversity indices of the representative genera were the highest in L. parasiticus during the same seasons. However, in M. colchinchinensis, the alpha diversity was also higher in the post-flowering season similar to another hemiparasite plant L. parasiticus. The ecological, taxonomic and complex correlation studies unravelled that the hemiparasites act as the potent reservoirs of endophytic communities throughout the year and during favourable conditions, these bacterial communities disseminate to the mango plant.
... Unraveling the distribution pattern of phyllosphere microbial communities on the Tibetan Plateau has been attracting the growing scientific interests of ecologists. The phyllosphere microbiome has been shown to play an important role in the adaptation of the plant host to different environmental stressors by enhancing tolerance to heat, cold, drought, and salinity (Al Ashhab et al., 2021). Investigating the change in bacterial communities along the altitudinal gradient will shed light on the prediction of future climatic changes scenario (Yuan et al., 2014). ...
... Plant phyllosphere harbor a diverse variety of microorganisms, which have been shown to play an important role in the adaptation of the plant host to different environmental stressors by enhancing tolerance to heat, cold, drought, UV radiation, and salinity (Al Ashhab et al., 2021). Plants in cold environments harbor complex, host-specific, and cold-adapted microbial communities, which may play a key functional roles in plant growth and survival under cold conditions. ...
... Climate is one of the major factors that shape microbial communities in the nature. The variations in phyllosphere bacterial community were related to environmental and biotic factors (Al Ashhab et al., 2021). Physiological profiles of the crop concerning abiotic factors affect the availability of nutrients, water, and a wide range of secondary metabolites on the leaf surface, which further and therefore significantly affect the epiphytic microbial communities . ...
The study aimed to reveal altitudinal distribution patterns of phyllosphere microbial communities and silage fermentation of Kobresia pygmaea along the elevation gradient on the Tibetan Plateau. The K. pygmaea was individually collected from 2,500, 3,000, 4,000, 4,500, and 5,000 m above sea level (a.s.l.) on the Tibetan Plateau and ensiled for 60 days, respectively. The phyllosphere bacterial diversity increased while fungal diversity decreased along the elevation gradient, and bacterial and fungal richness showed a unimodal distribution with peak abundance at 4,000 and 3,000 m a.s.l., respectively. After 60 days of ensiling, the bacterial and fungal community composition changed but did not exhibit clear altitudinal distribution patterns. All K. pygmaea underwent a weak fermentation indicated by pH above 5.0 and low ratio of lactic/acetic acid (LA/AA). The S5000 and S3000 showed the highest and lowest pH, respectively. Although Lactobacillus dominated S4000 after 60 days of ensiling, S4000 still exhibited poor fermentation quality as well as silages from the other four regions. The higher ammonia N concentrations in S3000 and S4000 than the other silages were consistent with the detectable butyric acid in S3000 and S4000. The silage fermentation of K. pygmaea collected from five regions exhibited poor fermentation quality, thereby inoculating lactic acid bacteria to K. pygmaea before ensiling is highly recommended to improve fermentation quality on the Tibetan Plateau.
