Leaf Endophytes Research Articles

Abundance of soil microbes, endophytic fungi and blast disease of paddy rice with three pest management practices

Abstract. Wiyono S, Istiaji B, Triwidodo H, Suryaningsih AS. 2020. Abundance of soil microbes, endophytic fungi and blast disease of paddy rice with three pest management practices. Biodiversitas 21: 4234-4239. Rice production in Indonesia faces a potential threat of pests and diseases. Biointensive Integrated Pest Management (Bio IPM) is a new approach based on natural and biological control, which effectively controls pests and diseases. However, the impact of this technology on soil microbes and endophytic fungi is almost unknown. The objective of the study was to investigate the effect of Bio IPM on abundance of soil microbes, endophytic fungi, and blast disease under field conditions. Three pest management types were tested i.e. conventional, reduced pesticides, and Bio IPM. Field experiment was set in four replications in randomized complete block design. Experiments were carried out in two seasons i.e. dry and wet season. Variables assessed during experiment were amount of soil bacteria, soil fungi, phosphate solubilizing bacteria, colonization of total leaf endophytes, colonization of Nigrospora sp., and blast disease severity. The results showed that the abundance of soil bacteria and phosphate solubilizing bacteria were significantly increased with Bio IPM whereas it was not found to be significant in soil fungi. Total endophytic fungi and Nigrospora sp. were found higher in Bio IPM especially in early growth stages. Bio IPM controlled neck blast more effectively than conventional and reduced pesticides, but it did not show any significant effect on leaf blast disease.

Apple endophyte community is shaped by tissue type, cultivar and site and has members with biocontrol potential againstNeonectria ditissima

This research aimed to identify factors influencing endophyte community structure in apple shoots and the bioactivity of cultured representatives against the fungal pathogen Neonectria ditissima. The endophyte community in leaves and stems of the apple cultivars 'Royal Gala' and 'Braeburn' were analysed by a cultivation-independent method (PCR-DGGE) which showed that tissue type, cultivar and site were determinant factors, with the endophyte taxa in 'Royal Gala' more variable than that in 'Braeburn', with leaf endophyte communities typically differing from stems in both cultivars. Seasonal (spring vs. autumn) and regional (Nelson vs. Hawke's Bay) variations were not obvious in woody stems. A collection of 783 bacterial and 87 fungal endophytes were recovered from leaves and stems of 'Royal Gala', 'Braeburn', 'Scilate' and/or 'Scifresh' from Nelson (nine sites) and Hawke's Bay (five sites) in spring and from Nelson (three sites) in autumn. A dual culture plating assay was used to test their ability to inhibit the mycelial growth of N. ditissima. Thirteen bacterial (mean of percent inhibition ≥ 20%) and 17 fungal isolates were antagonistic towards N. ditissima. These isolates belonged to the bacterial genera Bacillus and Pseudomonas, and fungal genera Chaetomium, Epicoccum, Biscogniauxia, Penicillium, Diaporthe, Phlyctema and two unidentified fungal isolates. Endophyte communities in apple shoots were determined by tissue type, cultivar and site. Endophytic bacterial and fungal isolates inhibiting N. ditissima growth in vitro were found. These results provided new evidence of factors influencing apple endophyte community in New Zealand. Endophytes with potential to reduce N. ditissima infection were identified, with the potential to be developed into a biocontrol strategy for European canker.

Distinct factors drive the assembly of quinoa-associated microbiomes along elevation

Unravelling the factors shaping microbial community structure across plant holobiont is required to promote plant health and crop productivity. We compared microbial communities in soils and plant compartments of two contrasting quinoa cultivars, grown in low-input cropping systems along an elevation gradient in northwest Yunnan plateau, China. With a compartment-dependent effect, alpha-diversity (Shannon and Chao1 indices) of both bacterial and fungal communities generally increased with increasing elevation. Both bacterial and fungal diversities decreased in the order of rhizosphere> root > leaf, but no significant difference was found between two plant genotypes or between bulk soil and rhizosphere. Representing a unique niche for microbial communities, leaf had a much stronger selection effect than root. With insignificant effect of plant genotype, local environmental filtering (i.e. climate, edaphic and plant traits) could have played an important role in structuring soil microbial communities, but they were weak for root and leaf endophytes, except for root fungi. The relative importance of stochastic and deterministic processes in bacterial or fungal communities varied with the elevational scale, showing contrasting patterns within each plant-associated compartment, except for leaf (determinism). The revealed distinct drives in determining the community assembly in quinoa-associated microbes are thought to be essential for underpinning plant–microbe interactions.

Metagenomic analysis of bacterial and fungal community composition associated with Paulownia elongata × Paulownia fortunei

The dynamics and interactions of microbial communities in Paulownia’s life cycle are poorly understood. The main goal of this study was to compare the rhizospheric soil and endophytic microbiome and mycobiome of hybrid Paulownia elongata and Paulownia fortunei. The comparison was based on highly efficient Illumina MiSeq sequencing of bacteria and fungi from the rhizosphere and endosphere of bioenergetic trees P. elongata x P. fortunei. The general richness of bacteria and rhizospheric fungi (based on Chao 1, Shannon, and Simpson indicators) was higher than in endosphere samples from the same plants. Actinobacteria and Proteobacteria were dominant in the rhizosphere and endosphere of plants in healthy conditions. The rhizosphere fungal communities in both trials were dominated by Ascomycota, Mortierellomycota, and Basidiomycota. Most root endophytes came from Olpidiomycota, Oomycota, and Ascomycota, while most leaf endophytes were from Ascomycota and Basidiomycota. This study was the first report on the composition of bacteria and fungi associated with the endosphere and rhizosphere of Paulownia trees. These studies showed that bacterial and fungal communities from the rhizosphere and endosphere were separate communities. It also showed that the health conditions of trees did not affect the composition of endophytic microorganisms in Paulownia tissues.

Tripartite Interactions Between Endophytic Fungi, Arbuscular Mycorrhizal Fungi, and Leymus chinensis.

Grasses often establish multiple simultaneous symbiotic associations with endophytic fungi and arbuscular mycorrhizal fungi (AMF). Many studies have examined pair-wise interactions between plants and endophytic fungi or between plants and AMF, overlooking the interplays among multiple endosymbionts and their combined impacts on hosts. Here, we examined both the way in which each symbiont affects the other symbionts and the tripartite interactions between leaf endophytic fungi, AMF, and Leymus chinensis. As for AMF, different species (Glomus etunicatum, GE; Glomus mosseae, GM; Glomus claroideum, GC; and Glomus intraradices, GI) and AMF richness (no AMF, single AMF taxa, double AMF mixtures, triple AMF mixtures, and all four together) were considered. Our results showed that significant interactions were observed between endophytes and AMF, with endophytes interacting antagonistically with GM but synergistically with GI. No definitive interactions were observed between the endophytes and GE or GC. Additionally, the concentration of endophytes in the leaf sheath was positively correlated with the concentration of AMF in the roots under low AMF richness. The shoot biomass of L. chinensis was positively related to both endophyte concentration and AMF concentration, with only endophytes contributing to shoot biomass more than AMF. Endophytes and AMF increased shoot growth by contributing to phosphorus uptake. The interactive effects of endophytes and AMF on host growth were affected by the identity of AMF species. The beneficial effect of the endophytes decreased in response to GM but increased in response to GI. However, no influences were observed with other GC and GE. In addition, endophyte presence can alter the response of host plants to AMF richness. When leaf endophytes were absent, shoot biomass increased with higher AMF richness, only the influence of AMF species identity outweighed that of AMF richness. However, when leaf endophytes were present, no significant association was observed between AMF richness and shoot biomass. AMF species identity rather than AMF richness promoted shoot growth. The results of this study demonstrate that the outcomes of interspecific symbiotic interactions are very complex and vary with partner identity such that the effects of simultaneous symbioses cannot be generalized and highlight the need for studies to evaluate fitness response of all three species, as the interactive effects may not be the same for each partner.

Contingency rules for pathogen competition and antagonism in a genetically based, plant defense hierarchy.

Plant defense against pathogens includes a range of mechanisms, including, but not limited to, genetic resistance, pathogen‐antagonizing endophytes, and pathogen competitors. The relative importance of each mechanism can be expressed in a hierarchical view of defense. Several recent studies have shown that pathogen antagonism is inconsistently expressed within the plant defense hierarchy. Our hypothesis is that the hierarchy is governed by contingency rules that determine when and where antagonists reduce plant disease severity.Here, we investigated whether pathogen competition influences pathogen antagonism using Populus as a model system. In three independent field experiments, we asked whether competition for leaf mesophyll cells between a Melampsora rust pathogen and a microscopic, eriophyid mite affects rust pathogen antagonism by fungal leaf endophytes. The rust pathogen has an annual, phenological disadvantage in competition with the mite because the rust pathogen must infect its secondary host in spring before infecting Populus. We varied mite–rust competition by utilizing Populus genotypes characterized by differential genetic resistance to the two organisms. We inoculated plants with endophytes and allowed mites and rust to infect plants naturally.Two contingency rules emerged from the three field experiments: (a) Pathogen antagonism by endophytes can be preempted by host genes for resistance that suppress pathogen development, and (b) pathogen antagonism by endophytes can secondarily be preempted by competitive exclusion of the rust by the mite. Synthesis: Our results point to a Populus defense hierarchy with resistance genes on top, followed by pathogen competition, and finally pathogen antagonism by endophytes. We expect these rules will help to explain the variation in pathogen antagonism that is currently attributed to context dependency.

Spatial patterns of fungal endophytes in a subtropical montane rainforest of northern Taiwan

Abstract Fungal endophytes of plants are ubiquitous and important to host plant health. Wood-inhabiting and foliar endophyte communities from multiple tree hosts were sampled at multiple spatial scales across the Fushan forest dynamics plot in northern Taiwan, using culture-free, community DNA amplicon sequencing methods. Fungal endophyte communities were distinct between leaves and wood, but the mycobiomes were highly variable across and within tree species. Despite this, host tree species was an important predictor of mycobiome community-composition. Within a single common tree species, “core” mycobiomes were characterized using co-occurrence analysis. The spatial co-occurrence patterns of these few species of fungal endophytes appear to explain the strong host effect. For wood endophytes, a consistent core mycobiome coexisted with the host across the extent of the study. For leaf endophytes, the core fungi resembled a more dynamic, “gradient” model of the core microbiome, changing across the topography and distance of the study.

Induced systemic salt tolerance in rice by indigenous bacteria isolated from Java coastal plants under gnotobiotic system

Bacteria associated with plants grown in saline natural habitat provide an advantage to the host they colonize and their utilization would give a great benefit for alleviating the salt stress to the plants growing in such environment. With the objective to find the most promising bacterial strains to be used for induction of salt tolerance in agricultural crops, we evaluated 12 bacterial isolates that previously isolated from plants grown in the Java coastal area. Gnotobiotic system was performed to test the ability of isolates in enhancing salt tolerance in three different varieties of rice (Ciherang, IF8, Situbagendit) under different levels of NaCl. The result suggested that promising isolates for enhanced salt tolerance in rice seedling are E194-3, D150 and R146-6 for root endophyte, leaf endophyte and rhizoplane respectively. Isolate E194-3 (root endophyte) gave the best result at highest concentration NaCl of 200 mM by increasing the root length, shoot length, fresh weight and dry weight 21%, 39%, 62% and 49% respectively (means from three rice varieties) in comparison to uninoculated control. This study suggested that gnotobiotic assay for evaluating rice seedling growth promotion by bacterial endophyte and rhizoplane under salt condition could be used for the selection of potential bacterial strains subjected to further testing of bacterial isolates to be used in inducing salt tolerance in rice under field conditions.

Leaf endophytes mediate fertilizer effects on plant yield and traits in northern oat grass (Trisetum spicatum)

Symbiotic fungi commonly increase plant acquisition of soil nutrients. Because prior work has focused on root fungi, we examined how leaf endophytes (Epichloe) influenced plant responses to fertilization and altered plant traits that may cascade to food webs and ecosystem processes. We manipulated endophyte presence/absence in two populations of Trisetum spicatum, a wild relative of oat, under a 2 × 2 addition of soil nitrogen (N) and phosphorus (P) in the greenhouse. Endophyte symbiosis altered how plant biomass responded to soil N and how plant traits responded to soil P. Endophytes boosted the biomass gains from N-fertilization in one population. Plants from a second population had weak benefits of symbiosis, but the endophyte altered plant traits, by increasing specific leaf area under P-fertilization, root diameter under low P, and concentration of the fungal alkaloid AcAP under N fertilization. Endophyte presence suppressed the typically observed increase in root hair density in response to soil P limitation. Under low P, symbiotic plants from both populations had improved forage quality relative to symbiont-free plants, although N-fertilization had a larger effect size on forage quality than did symbiosis. Finally, the two populations differed in production of fungal alkaloids, which generally increased in response to fertilization. Predicting how microbial symbionts mediate plant acquisition of nutrients requires understanding how much their effects vary among plant and endophyte genotypes. Here, the magnitude and direction of leaf symbionts’ effects on plant yield and traits varied between populations and with soil nutrient availability.

Distribution and diversity of foliar endophytic fungi in the mangroves of Andaman Islands, India

Abstract Fungal endophytes represent a major component of plant microbiomes. Various aspects of these fungi such as their diversity and technological potential have been studied in detail. However, their distribution and diversity in a mangrove community has not been addressed. In this study, we report the presence of culturable fungal endophytes from 20 obligate mangrove hosts from south Andaman Islands. Phomopsis/Diaporthe was isolated from all the mangrove species studied while Xylaria, Colletotrichum and Phyllosticta were recorded from the majority of the mangroves studied. A phylogenetic analysis of representative Phomopsis/Diaporthe isolates clearly indicated the broad host range of this genus. Our study also highlighted the fact that leaf endophytes of mangroves are not unique with reference to their species diversity and frequency of occurrence when compared to those of terrestrial plants. These observations suggest that the extraordinary success of some fungal endophytes in colonizing taxonomically disparate hosts could be due to development of traits specific to their ecosystem.

The Potency of Bacterial Associating Endemic Plants of The Java Coastal Area in Inducing Salt Tolerant in Agricultural Crops

Recent studies indicate that many plant species have ability to adapt to environmental stress because of their association with microbes. The aim of the research is to explore and to characterize bacterial endophyte and rhizoplane from endemic plants of the Java coastal area that induced salt tolerance in agricultural crops. Among the 1358 isolates of salt tolerant bacteria that have been isolated from 218 of different costal plants showed that 108 isolates of bacterial rhizoplane, 87 isolates of bacterial root endophytes and 35 isolates of bacterial leaf endophyte have the ability to promote rice seedling growth. An amount of 33 isolates with vigor index (VI) value more than 1200 were tested at different levels of NaCl concentration (0, 50, 100, 150 and 200 mM). Fifteen bacterial isolates significantly increased VI value of rice seedling by up to 50% over uninoculated control at NaCl concentration more than 100 mM. Characterization of these 33 isolates revealed 32 isolates degraded pectin, 26 isolates produced indole acetic acid (IAA), 18 isolates solubilized phosphate, 15 isolates showed 1aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, 11 isolates produced hidrogene cyanide (HCN).

Comparative evaluation of physico-chemical characteristics of biopolyesters P(3HB) and P(3HB-co-3HV) produced by endophytic Bacillus cereus RCL 02

Bacteria endogenously residing within the plant tissues have attracted significant attention for production of biopolyester, polyhydroxyalkanoates (PHAs). Bacillus cereus RCL 02 (MCC 3436), a leaf endophyte of oleaginous plant Ricinus communis L. accumulates 81% poly(3-hydroxybutyrate) [P(3HB)] of its cell dry biomass when grown in mineral salts (MS) medium. The copolymer production efficiency of B. cereus RCL 02 was evaluated in valeric acid supplemented MS medium under biphasic cultivation condition. The copolymer so produced has been compared with the P(3HB) isolated from RCL 02 in terms of thermal, mechanical and chemical properties. Valeric acid supplementation as co-substrate in the medium has led to the production of copolymer of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) [P(3HB-co-3HV)] with 14.6 mol% 3HV. The identity of the polymers has been confirmed by X-ray diffraction (XRD) analysis, Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopic studies. Thermogravimetric analysis (TGA) revealed that P(3HB) and P(3HB-co-3HV) films degraded at 278.66°C and 273.49°C, respectively. The P(3HB-co-3HV) showed lower melting temperature (165.03°C) compared to P (3HB) (170.74°C) according to differential scanning calorimetry (DSC). Incorporation of 3HV monomers decreased the tensile strength (21.52 MPa), tensile modulus (0.93 GPa), storage modulus (E′) (0.99 GPa) and increased % elongation at break (12.2%) of the copolyester. However, P(3HB) showed better barrier properties with lower water vapor transmission rate (WVTR) of 0.55 g-mil/100 in2/24 h. These findings emphasized exploration of endophytic bacterial strain (RCL 02) to produce biodegradable polyesters which might have significant potential for industrial application.

Colonization cues of leaf- and root-inhabiting bacterial microbiota of Atractylodes lancea derived in vitro and in vivo

Recent studies have demonstrated that leaf inhabiting endophytic bacteria can be selective derived from the air, and root inhabiting endophytic bacteria can selectively come from the soil. We wonder if inhabiting bacteria in plant leaves can also come from the roots, and vice versa. We designed an experimental device to study plant Atractylodes lancea acquirements of bacterial endophytes from both the inside and abiotic environment. Inhabiting bacterial microbiota and volatile oil profiles in leaf and root compartment of Atractylodes lancea were estimated through Illumina Mi-seq platform and gas chromatography, respectively. The majority of inhabiting bacterial endophytes in leaves and roots were coming from the soil. However, air-borne bacteria also participated in defining root endophytic bacteria populations. The bacteria population from different Atractylodes lancea compartments are under different selection, thus ultimately root and leaf endophyte types differ, which ultimately influence the volatile oil profiles in the leaf and root compartments of Atractylodes lancea. These results provide a first glimpse of the inhabiting bacterial microbiota that transmit between inside of plant leaf and root compartments.

Screening Endophytes of Neem Leaf that Potential Anti-Anthrax through Tests of Anti Staphylococcus Aureus

Anthrax is a deadly disease caused by Bacillus antracis that damages the lymphatic and vascular systems of animals and humans. Anthrax prevention in Indonesia has been done but has many shortcomings among them is a lot of dead animal raises after vaccination and relatively expensive. The azadirachtin bioactive compound produced by neem endophytic microbes is known to inhibit the growth of B. anthracis bacteria, thus potentially as an anti-anthrax agent. Other bacteria that have the same pathogens as B. antrachis are Methycillin Resistant Staphylococcus aureus (MRSA) so that it is used as a research object. The aim of this research is to obtain the active biomaterials from selected neem leaf endophytes to be tested in S. aureus MRSA as bacteria with Anthrax pathogens. The method used in this research is the isolation, selection, and extraction of Neem endophytes. The process of isolation is done by growing on the general media and the selection process on special media. The bioactive extraction process uses 1000 rpm centrifuge and screening on MRSA culture medium. Inhibitory zone tests were used to determine the effect of endophytic biopsy in inhibiting MRSA growth. The result of the research is that the bioactive endophytes of neem are able to inhibit MRSA growth which is characterized by the formation of drag zone around the endophytic bioactive. Thus it can be concluded that the use of neem endophytes can be a new solution to eradicate the presence of anthrax disease in the livestock and people in Indonesia with safe research methods, relatively inexpensive and ineffective vaccine replacements.

Isolation of weed leaf endophytes for crop growth promotion

Isolation of weed leaf endophytes for crop growth promotion

Application of weighted response surface methodology for enhanced poly (3-hydroxybutyrate) production by endophytic bacillus cereus RCL 02

Application of statistical models in developing strategies for process optimization and enhanced product yield is well established. The present study is focused to enhance poly (3-hydroxybutyrate) [P(3HB)] production by Bacillus cereus RCL 02, a leaf endophyte of oleaginous plant Ricinus communis L. using weighted response surface methodology (WRSM). The most influencing process variables for growth and bio-polyester accumulation were initially selected through Plackett-Burman (PB) designed experiments. Further, WRSM was applied to navigate the experimental data obtained in accordance with the central composite design (CCD). Interaction of three independent variables viz. carbon source (glucose), nitrogen source (yeast extract) and initial pH of the medium exerted most significant impact on biomass formation as well as P(3HB) production. A second order polynomial equation obtained from multiple regression analysis and the interaction studies from surface plots helped to determine the optimum concentrations of glucose (25g/L), yeast extract (4g/L) and initial pH (7.6). Validation of this statistical model was executed using point prediction tool of WRSM where-from the optimum values of all three significant variables were employed and experiments were conducted. Under such optimized conditions the endophytic isolate produced 8.07g/L of P(3HB), which was very close to the predicted value (7.80g/L) and thereby validated the model. Finally, the identity of the intracellularly accumulated bio-polyester of B. cereus RCL 02 was confirmed by proton nuclear magnetic resonance (1H NMR) spectroscopic analysis.

A re-evaluation of Tubakia, including three new species on Quercus and six new combinations.

Morphological comparisons and phylogenetic analyses of Tubakia species from leaves of Quercus spp. in Iowa and other areas of eastern USA revealed three novel species: Tubakia hallii, Tubakia macnabbii, and Tubakia tiffanyae. These species, as well as Tubakia dryina and Tubakia iowensis, are common leaf endophytes and pathogens on Quercus and Castanea in eastern USA, as is Tubakia americana comb. nov, originally described from Quercus in New Jersey as Actinopelte americana. New combinations of species on leaves of other hosts in the eastern USA include Tubakia gloeosporioides, Tubakia liquidambaris, and Tubakia nyssae. Asian species of Tubakia are phylogenetically compared, and the new combination Tubakia supraseptata is made to accommodate a Japanese endophyte known only by its sexual state. The earlier description of Dicarpella dryina as the sexual state of T. dryina is questioned. The new combination Tubakia stellata is made to accommodate an unusual species from Brazil.

Antimicrobial Drimane Sesquiterpenes Contribute to Balanced Antagonism but Do Not Structure Bacterial and Fungal Endophytes in the African Pepper Bark Tree Warburgia ugandensis

The African pepper bark tree, Warburgia ugandensis, accumulates antimicrobial drimane sesquiterpenes in all of its organs. One hypothesis states that plant defense compounds determine endophyte community structure. Another hypothesis suggests that they just facilitate the endophytic lifestyle by exerting a balanced antagonism. To explore this, a representative selection of endophytic bacterial and fungal isolates from this tree species was assayed together with six non-endophytic strains to determine their tolerance and susceptibility to the root and leaf extract fraction containing high and low drimane sesquiterpene amounts respectively. Inhibitory effects were explored by assessing both growth and growth efficiency, the latter of which relates respiratory activity to growth. The susceptibility of the tested strains showed considerable variation and the obtained patterns did not allow a clear distinction between root and leaf endophytes as well as endophytes and non-endophytes. In addition, all strains were also assayed against juglone, an antimicrobial and redox-active aromatic naphthoquinone. A comparison of differential pulse voltammograms and efficacy in variants of the deoxyribose degradation assay revealed that drimane sesquiterpenes possess anti- and pro-oxidant activities that compare to those of juglone. Leaf endophytes showed higher resistance to oxidative stress than root endophytes, quite contrary to the actual exposure. The obtained results support the notion that structural diverse plant defense compounds can contribute to a balanced antagonism against but not to structuring of endophyte communities. Oxidative stress seems to be involved in generating this effect albeit it cannot explain it alone.

Transient leaf endophytes are the most active fungi in 1-year-old beech leaf litter

The ecological significance of fungi occurring asymptomatically inside living plant leaves is poorly understood. Given the broad saprotrophic potential of many endophytic fungi, we hypothesized that they persist in decaying litter for an extended period of time after leaf abscission. Fungal assemblages were assessed by high-throughput sequencing in autumn leaves of beech (Fagus sylvatica) and in the corresponding leaf litter in 388 samples from 22 beech forest plots in three widely distant regions of Germany. A considerable proportion of the leaf-endophytic fungi was also found in 1-year-old litter. Co-occurrence networks revealed that the fungi formed unstructured assemblages inside the living leaves, rather than well-structured communities. Previously endophytic fungi constituted an integral part of the fungal litter community and were by far the most active fungi in 1-year-old litter. We therefore consider these endophytic occurrences to represent transient stages. Composition of the aboveground microbiome appears therefore to be closely connected to the process of litter decomposition. Considering the respective linked fungal habitat will facilitate predicting nutrient and carbon cycling and storage in forest ecosystems as well as elucidating the ecology of leaf microbiomes.

Climate and dispersal influence the structure of leaf fungal endophyte communities of Quercus gambelii in the eastern Great Basin, USA

Abstract Endophytic fungi form communities within living plant tissues. Their functions vary tremendously so the structures of their communities influence plant and ecosystem functions. We determined the separate effects of neutral and deterministic processes structuring communities of Quercus gambelii leaf endophytes by sampling north- and south-facing flanks of four canyons so local climate varied independently from spatial separation. We found that both deterministic (response to climate) and neutral (dispersal limitation) processes significantly influenced community structure. These findings, if applicable to other systems, may have consequences in both agricultural and natural ecosystems. Endophyte dispersal could limit agricultural production, ecosystem restoration or natural plant establishment. Thus deliberate inoculation may prove useful in some situations. Moreover, the influence of climate on fungal endophyte communities indicates that climate change may not only impact plant distributions directly, but may also do so indirectly via the effect of endophytes on plant tolerance to temperature and moisture extremes.