Search Results (44)

The Qinghai–Tibet Plateau is a key region for biodiversity conservation, where alpine grasslands are ecologically important. While previous studies have mainly addressed vegetation, ecosystem processes, and soil microbes, phyllosphere microorganisms are essential for nutrient cycling, plant health, and stress tolerance. However, their communities remain poorly understood compared to those in soil. The relative influence of host identity and environmental conditions on shaping phyllosphere microbial diversity and community assembly remains uncertain. In this study, we characterized phyllosphere bacterial and fungal communities of the phyllosphere at two alpine steppe sites with similar vegetation but climatic conditions: the Qilian Mountains (QLM) and the Qinghai Lake region (LQS). At both sites, Cyanobacteriota and Ascomycota were the predominant bacterial and fungal taxa, respectively. Microbial α-diversity did not differ significantly between the two regions, implying that host-associated mechanisms may stabilize within-site diversity. In contrast, β-diversity exhibited clear spatial differentiation. In QLM, bacterial β-diversity was significantly correlated with mean annual precipitation, while fungal α- and β-diversity were associated with soil nutrient levels (including nitrate, ammonium, available potassium, and phosphorus) and vegetation coverage. At LQS, the β-diversity of both bacterial and fungal communities was strongly influenced by soil electrical conductivity, and fungal communities were further shaped by vegetation cover. Community assembly processes were predominantly stochastic at both sites, although deterministic patterns were more pronounced in QLM. Variability in moisture availability contributed to random bacterial assembly at LQS, while increased environmental heterogeneity promoted deterministic assembly in fungal communities. The elevated diversity of microbes and plants in QLM also reinforced deterministic processes. Overall, our findings support a host–environment interaction hypothesis, indicating that host factors primarily govern α-diversity, while climatic and soil-related variables have stronger effects on β-diversity and microbial assembly dynamics. These insights advance our understanding of how phyllosphere microbial communities may respond to environmental change in alpine ecosystems. Full article

China has significant mineral resources, but prolonged extraction has caused considerable environmental degradation. Interactions among rhizosphere, phyllosphere, and soil microorganisms, along with host plants, are essential for supporting plant growth and increasing stress tolerance. This study employed high–throughput sequencing to assess microbial diversity and community structure related to four common tree species in the mountainous areas of Shanxi Province, with samples collected from three regions over two seasons and three locations. The dominant fungal and bacterial phyla identified were Ascomycota, Basidiomycota, Mortierellomycota, Pseudomonadota, Actinobacteriota, Gemmatimonadota, Acidobacteria, Myxococcota, and Firmicutes. Alpha–diversity analysis revealed that Taiyue Mountain exhibited the highest fungal diversity among the plots, while Liushenyu displayed the highest bacterial diversity. Alpha–diversity was greater in spring than in summer across the seasons. Significant differences in Alpha–diversity were observed among different tree species, with Betula platyphylla showing the lowest diversity. In comparison to phyllosphere microorganisms, rhizosphere and soil microorganisms exhibited higher diversity, richness, and evenness. Beta–diversity analysis indicated significant differences in fungal and bacterial community composition between spring and summer samples, as well as among samples from leaves, roots, and soil. The assessment of soil physicochemical properties and redundancy analysis demonstrated that soil moisture content and organic matter were key factors influencing the composition of fungal and bacterial communities. These findings provide valuable insights into the structural changes in plant microbial communities in mining areas and the restoration of damaged ecosystems. Full article

The phyllosphere represents the largest biological surface on Earth and serves as an untapped reservoir of functional microbiota. The phyllosphere microbiome has the potential to mitigate plant diseases; however, limited information exists regarding its role in maintaining plant health. In this study, metagenomic sequencing was employed to analyze the microbiomes of the adaxial and abaxial leaf surfaces of healthy (CKWT) and diseased (EWT) maize, with the aim of dissecting the influence of Exserohilum turcicum on phyllosphere microbiome function. E. turcicum altered the alpha and beta diversity of the phyllosphere microbiome, with the Shannon diversity and Chao1 index values significantly reduced in EWT. More beneficial microbes accumulated in the CKWT phyllosphere, whereas pathogenic microbes decreased. E. turcicum may have altered the balance between commensal and pathogenic microorganisms. The species and abundances of microorganisms on the two sets of leaf surfaces were also altered after inoculation with E. turcicum. Further analysis of disease-resistance-related metabolic pathways and abundances of antibiotic-resistance genes revealed that E. turcicum altered the abundance of the functional microbiome and modified the microbiome differences between adaxial and abaxial leaf surfaces. In conclusion, the results reveal that microbial diversity in the maize phyllosphere can influence the microbiome and regulate microbial functions to support plant health. These findings enhance our understanding of how E. turcicum affects the phyllosphere microbiome and provide a theoretical basis for biological control of E. turcicum. Full article

The phyllosphere is one of the largest habitats for microorganisms, and host genetic factors play an important role during the interaction between microorganisms and the phyllosphere. Therefore, the transgene may also lead to changes in the maize phyllosphere. ZmMYB3R was identified as a drought-tolerant gene in Arabisopsis. Here, we employed metagenomic sequencing to analyze the microbiome of the adaxial and abaxial leaf surfaces on ZmMYB3R-overexpressing (OE) and wild-type (WT)·maize, aiming to dissect the possible associations between ZmMYB3R and changes in phyllosphere microbiome functioning. Our results revealed that overexpressing ZmMYB3R altered the alpha and beta diversity of the phyllosphere microbiome. In OE plants, more beneficial microbes accumulated on the phyllosphere, while pathogenic ones diminished, especially on the abaxial surface of ZmMYB3R leaves. Further analysis of disease resistance-related metabolic pathways and abundances of disease resistance genes revealed significant differences between OE and WT. The inoculation experiment between OE and WT proved that ZmMYB3R increased the disease resistance of maize. In conclusion, the results reveal that transgenes affect the phyllosphere microbiome, and ZmMYB3R might alter leaf disease resistance by reshaping the phyllosphere microbiome structure. These findings help us understand how ZmMYB3R regulates leaf disease resistance and may facilitate the development of disease control by harnessing beneficial microbial communities. Full article

The plant microbiome, found in the rhizosphere, phyllosphere, and endosphere, is essential for nutrient acquisition, stress tolerance, and the overall health of plants. This review aims to update our knowledge of and critically discuss the diversity and functional roles of the rice microbiome, as well as microbiome engineering strategies to enhance biofertilization and stress resilience. Rice hosts various microorganisms that affect nutrient cycling, growth promotion, and resistance to stresses. Microorganisms carry out these functions through nitrogen fixation, phytohormone and metabolite production, enhanced nutrient solubilization and uptake, and regulation of host gene expression. Recent research on molecular biology has elucidated the complex interactions within rice microbiomes and the signalling mechanisms that establish beneficial microbial communities, which are crucial for sustainable rice production and environmental health. Crucial factors for the successful commercialization of microbial agents in rice production include soil properties, practical environmental field conditions, and plant genotype. Advances in microbiome engineering, from traditional inoculants to synthetic biology, optimize nutrient availability and enhance resilience to abiotic stresses like drought. Climate change intensifies these challenges, but microbiome innovations and microbiome-shaping genes (M genes) offer promising solutions for crop resilience. This review also discusses the environmental and agronomic implications of microbiome engineering, emphasizing the need for further exploration of M genes for breeding disease resistance traits. Ultimately, we provide an update to the current findings on microbiome engineering in rice, highlighting pathways to enhance crop productivity sustainably while minimizing environmental impacts. Full article

Biological nitrogen (N) fixation has been advocated in agricultural fields due to being considered a more sustainable way to introduce N into agrosystems than industrial N fertilizers. In this study, a foliar spray inoculant containing the microorganism Methylobacterium symbioticum was applied. This microorganism is known for fixing N in the phyllosphere, regardless of the cultivated species. This study was conducted in three rainfed olive orchards over three years. In two orchards managed according to European Union (EU) integrated production rules, the experiment was organized as a factorial design with inoculant (applied at two levels, yes and no) and N fertilization (applied to the soil at three levels, 0, 40, and 80 kg ha⁻¹ of N). The third trial, managed according to EU organic farming rules, was organized in a completely randomized design with three treatments: with (yes) and without (no) inoculant and with a treatment involving a seaweed extract, also for foliar application. The microbiological inoculant did not consistently influence olive yield or N concentration in leaves across the three trials. Conversely, N application to the soil significantly influenced N concentration in leaves and olive yield. In one of the trials, in the third year of the study, soil N application (80 kg ha⁻¹) resulted in an olive yield of ~eight times higher than the unfertilized control treatment. The seaweed extract also did not lead to significant differences in leaf mineral composition or olive yield compared with the other treatments. These findings from the on-farm research highlight the importance of accurately determining the conditions under which commercial products can deliver effective results. It is crucial to acknowledge that these products involve expenses not only in their acquisition but also in their application. Full article

Fungal biota represents important constituents of phyllosphere microorganisms. It is taxonomically highly diverse and influences plant physiology, metabolism and health. Members of the order Diaporthales are distributed worldwide and include devastating plant pathogens as well as endophytes and saprophytes. However, many phyllosphere Diaporthales species remain uncharacterized, with studies examining their diversity needed. Here, we report on the identification of several diaporthalean taxa samples collected from diseased leaves of Cinnamomum camphora (Lauraceae), Castanopsis fordii (Fagaceae) and Schima superba (Theaceae) in Fujian province, China. Based on morphological features coupled to multigene phylogenetic analyses of the internal transcribed spacer (ITS) region, the large subunit of nuclear ribosomal RNA (LSU), the partial beta-tubulin (tub2), histone H3 (his3), DNA-directed RNA polymerase II subunit (rpb2), translation elongation factor 1-α (tef1) and calmodulin (cal) genes, three new species of Diaporthales are introduced, namely, Diaporthe wuyishanensis, Gnomoniopsis wuyishanensis and Paratubakia schimae. This study contributes to our understanding on the biodiversity of diaporthalean fungi that are inhabitants of the phyllosphere of trees native to Asia. Full article

The phyllosphere (aerial plant surfaces colonized by microorganisms) remains an understudied ecosystem in terms of bacterial biogeography, particularly at intermediate or local spatial scales. This study characterized the phyllosphere bacterial community on the leaves of 87 Magnolia grandiflora trees sampled throughout a small town, encompassing an area of approximately 60 km². Sequencing of the 16S ribosomal RNA gene revealed the dominant bacterial phyla to be Alphaproteobacteria, Bacteroidetes, and Acidobacteria, consistent with other studies of the phyllosphere. There was a small but significant relationship between the phyllosphere community similarity and the distance between the trees (i.e., trees further apart were more likely to have dissimilar bacterial communities). There was also a relationship between the assigned categories of tree height (low, medium, high) and the phyllosphere bacterial community composition, with the trees in the high category having more diverse bacterial communities on their leaves than the shorter trees. This study provides insight into the relationship between phyllosphere community composition and host tree characteristics and shows that the distance between M. grandiflora trees has a significant, albeit low, influence on bacterial composition. These findings contribute to a deeper understanding of phyllosphere microbiome biogeography, highlighting how individual tree characteristics and spatial proximity shape phyllosphere bacterial communities. Full article

Anthracnose of Camellia plants is caused by the Colletotrichum species. The fungal pathogens mainly infect the leaves of plants and lead to serious economic losses. However, knowledge of Camellia phyllosphere microbial community after Colletotrichum infection has not been explored which limited our understanding of the relationship between the Camellia anthracnose outbreak and interacting microorganisms. In this study, three economically and ecologically important Camellia species with anthracnose symptoms were collected and subjected to bacterial and fungal composition analysis, diversity, co-occurrence characteristics, isolation of key strains, and tie-back pathogenicity test. The results indicated that Sphingomonas and Methylobacterium were the dominant bacterial genera over the three Camellia species and Pallidocercospora, Colletotrichum, and Pichia were the dominant fungal genera. The co-occurrence analysis showed that Methylobacterium, Sphingomonas, Massilia, and Allorhizobium were the key bacterial taxa and Colletotrichum, Pallidocercospora, Pichia, Septophoma, and Septoria were the key fungal taxa over the three infected plants. The hub taxa, including the species significantly associated with the Colletotrichum abundance, were mostly beneficial bacteria over the three Camellia species. Further co-culture and tie-back pathogenicity tests verified that the hub taxa associated with pathogenic Colletotrichum in the microbial networks may play promoting/inhibiting roles on Colletotrichum infection. The results highlight the importance of phytopathological conditions for the interactions between microbial members of foliar fungal and bacterial communities. Full article

The phyllosphere, comprising the aerial portions of plants, is a vibrant ecosystem teeming with diverse microorganisms crucial for plant health and productivity. This review examines the functional roles of phyllosphere microorganisms in rice (Oryza sativa), focusing on their importance in nutrient uptake, disease resistance, and growth promotion. The molecular mechanisms underlying these interactions are explored along with their potential applications in enhancing sustainable rice production. The symbiotic relationships between rice plants and their associated microorganisms are highlighted, offering insights into improved agricultural practices. Furthermore, this review addresses the challenges and future developments in translating laboratory findings into practical applications. By synthesizing current research, this comprehensive analysis serves as a valuable resource for leveraging phyllosphere microbes in rice farming and related fields. Full article

Anthocyanins, key quality components of tea, act as an important bridge between plants and the environment due to their function on protecting plants from biotic and abiotic irritants. This study aimed to assess the interactions between anthocyanins metabolism and the environment. Purple (P) and green (G) leaves with different anthocyanin contents were inoculated with tea plant anthracnose. High-throughput metabolomics and 16S microbial diversity sequencing methods were used to screen the anthocyanin fractions of tea plant leaves responsive to anthracnose. The interconnections between metabolites and the resistance of phyllosphere microorganisms to fungal pathogens were then analyzed. The results showed that leaves with high anthocyanin content (0.14% of diseased area ratio) were less impacted by anthracnose infestation than leaves with low anthocyanin (3.12%). The cyanidin content decreased after infection in purple leaves (PR) and increased in green leaves (GR). The relative abundance of Cyanobacteria was suppressed by the significant enrichment of Proteobacteria after anthracnose infection in green leaves. However, there were no significant differences between these two groups of microorganisms in purple leaves. Collinear network analysis revealed a strong correlation between Cyanobacteria and Dihydrosorbinol and between Proteobacteria and cyanidin metabolites. Among them, OTU456 (Bosea) was identified as the key taxonomic group of bacterial communities in the green-infected leaf network. In summary, the anthracnose resistance benefits from cyanidin mediated by proteobacteria in tea plants. These results deepen our understanding of the regulation of secondary metabolism in tea plants and the formation of plant resistance. Full article

Plant leaves harbor a rich diversity of bacteria and fungi that, through their interactions with host plants, assume an influential role in plant physiological and metabolic processes. The unique phyllosphere environment of different plant species may shape and select distinct phyllosphere microbial communities. While most academic research has focused on the phyllosphere microorganisms within the same plant variety, there is relatively limited research on the phyllosphere microbial communities between different varieties. Populus L. is a typical tree species in temperate monsoon climates, widely distributed in northern China, and it constitutes a crucial component of China’s forestry resources. For the purpose of this study, we investigated the community structure and diversity of phyllosphere fungi and bacteria in different poplar varieties under identical growth conditions to elucidate the main factors contributing to differences in phyllosphere microbial communities among these varieties. Our findings revealed variations in nitrogen, phosphorus, starch, and soluble sugar contents among the three poplar species studied. Additionally, there were considerable disparities in both abundance and α diversity index of phyllosphere fungal and bacterial communities among these species. At the phylum level, Ascomycota and Basidiomycota have been identified as the dominant fungal communities; while Proteobacteria and Actinomycetes were dominant bacterial communities. The correlation analysis pointed out that chemical traits in the leaves, in particular the total phosphorus and the quantity of soluble sugar, had a significant correlation with the structure and diversity of the microbial community residing in the phyllosphere. Overall, our results demonstrate that even under identical site conditions, each poplar species harbors its own unique phyllosphere microbial community composition as well as distinct leaf characteristics—highlighting host plant diversity as a crucial factor driving differences in phyllosphere microbial composition. Full article

Leymus chinensis is a high-quality forage with wide distribution. Disease is an important factor affecting the yield and quality of L. chinensis. To investigate the effect of grazing on the phyllosphere microbiome community and leaf spot disease in L. chinensis, high-throughput sequencing technology was used to study the differences in the composition and structure of the phyllosphere fungal and bacterial communities of healthy and diseased leaves under different grazing intensities. The results showed that grazing significantly reduced leaf spot disease incidence and severity. There were significant differences in the phyllosphere microbiome composition between healthy and diseased leaves, and interestingly, diseased leaves showed more complex microbial activity. Grazing altered the relative abundance of micro-organisms and affected microbial dispersal and colonization either directly through behavior or indirectly by altering plant community structure. In this study, we found that the phyllosphere microbiome responded strongly to pathogen infection, and that plants recruited beneficial microbes to protect themselves after disease development. Grazing could regulate microbial community composition and structure, either directly or indirectly, and plays a crucial role in maintaining the health of L. chinensis. Full article

Closely-related plant groups with distinct microbiomes, chemistries and ecological characteristics represent tractable models to explore mechanisms shaping species spread, competitive dynamics and community assembly at the interface of native and introduced ranges. We investigated phyllosphere microbial communities, volatile organic compound (VOC) compositions, and potential interactions among introduced S. trilobata, native S. calendulacea and their hybrid in South China. S. trilobata exhibited higher α diversity but significantly different community composition compared to the native and hybrid groups. However, S. calendulacea and the hybrid shared certain microbial taxa, suggesting potential gene flow or co-existence. The potent antimicrobial VOC profile of S. trilobata, including unique compounds like p-cymene (13.33%), likely contributes to its invasion success. The hybrid’s intermediate microbial and VOC profiles suggest possible consequences for species distribution, genetic exchange, and community assembly in heterogeneous environments. This hybrid deserves further study as both an opportunity for and threat to diversity maintenance. These differentiating yet connected plant groups provide insight into ecological and evolutionary dynamics shaping microbiome structure, species co-occurrence and competitive outcomes during biological exchange and habitat transformation. An interdisciplinary approach combining chemical and microbial ecology may reveal mechanisms underlying community stability and change, informing management of species spread in a globalized world. Full article

The phyllosphere is an important but underestimated habitat for a variety of microorganisms, with limited knowledge about leaf endophytes as a crucial component of the phyllosphere microbiome. In this study, we investigated the mechanisms of communities and co-occurrence networks of leaf endophytes in response to forest thinning in a temperate forest. As we expected, contrasting responses of fungal and bacterial endophytes were observed. Specifically, the diversity of leaf endophytic fungi and the complexity of their co-occurrence networks increased significantly with thinning intensity, whereas the complexity of endophytic bacterial co-occurrence networks decreased. In particular, microbiota inhabiting damaged leaves seem to be more intensively interacting, showing an evident fungi–bacteria trade-off under forest thinning. In damaged leaves, besides the direct effects of thinning, thinning-induced changes in neighbor tree diversity indirectly altered the diversity of leaf fungal and bacterial endophytes via modifying leaf functional traits such as leaf dry matter content and specific leaf area. These findings provide new experimental evidence for the trade-offs between leaf endophytic fungi and bacteria under the different magnitudes of deforestation, highlighting their dependence on the presence or absence of leaf damage. Full article