Root Endophytic Fungi Research Articles

P3-1-9 Isolation of root endophytic fungi from forest soils in Indonesia and its effect on growth of Paraserianthes falcataria and Brassica campestris

P3-1-9 Isolation of root endophytic fungi from forest soils in Indonesia and its effect on growth of Paraserianthes falcataria and Brassica campestris

Root-associated fungal communities along a primary succession on a mine spoil: Distinct ecological guilds assemble differently

The aim of the study was to explore fungal community assembly during spontaneous primary succession. Pyrosequencing was used to investigate the root-associated fungal communities of two dominant trees Salix caprea and Betula pendula along a primary successional chronosequence (12-, 20-, 30- and 50-year-old sites) on a mine spoil bank in the Czech Republic. Ecological guilds were parsed to fungal OTUs and subsequent multivariate analyses revealed that communities of ectomycorrhizal fungi (EcMF), fungal plant pathogens (PaF) and fungal root endophytes (EndF) changed statistically significantly along the successional chronosequence. Arbuscular mycorrhizal fungi (AMF) were very rare across all samples. EcMF and PaF communities were strongly related to the development of the entire plant community along the succession, while this relationship was much less pronounced for EndF communities. Early stage EcMF communities dominated by Pezizales were subsequently replaced by Thelephorales and Russulales in later successional sites. Positive correlation with site age was also found for EndF from order Helotiales. No significant differences were observed between the fungal communities of S. caprea and B. pendula in our study. We conclude that fungal taxa with tight ecological relationship to plants assemble with close feedback to plant communities, which change along the chronosequence, whereas communities of fungal endophytes develop more stochastically during the primary succession.

Characterization of the root and soil mycobiome associated with invasive Microstegium vimineum in the presence and absence of a native plant community

The potential role of fungal root endophytes (including mycorrhizae) in the invasiveness of Microstegium vimineum (Trin.) A. Camus, was researched using automated ribosomal intergenic spacer analysis (ARISA) and brightfield microscopy. Fungal communities of roots from two native plants (Onoclea sensibilis L. and Amphicarpaea bracteata (L.) Fernald) were compared with those found in Microstegium. Fungal communities from the bulk soils also were examined in terms of their potential influence on the root mycobiomes. All three plants occurred in natural communities as monocultures and together in one mixed community in Northern Virginia where Microstegium has recently invaded. Principal coordinate analysis of ARISA data identified fungal communities unique to roots from each monoculture. When the three plants co-occurred in a mixed setting, Microstegium was found to maintain its distinct fungal community while the fungal communities of the two native plants overlapped. In contrast, soil fungal communities showed no specific plant associations. Brightfield microscopy confirmed the presence of endophytic fungi in all three plants. The results recorded here suggest a positive contribution by the root mycobiome in promoting the invasive ability of Microstegium, providing a basis for future experiments testing this hypothesis.

ASSESSMENT OF BIOACTIVE METABOLITES FROM THE ROOT ENDOPHYTE ISOLATED FROM CASUARINA JUNGHUHNIANA Miq.

Objective: Casuarina junghuhniana Miq is a well known multipurpose tree belonging to family Casuarinaceae. This tree has the ability to sustain in different edaphic and extreme environmental conditions. The root extract of this tree is a rich source of potential secondary metabolites. Therefore, the main objective of this study is to isolate fungal root endophyte from this tree and to determine its bioactive compound which can be utilized in agriculture and pharmaceutical industries.Methods: Casuarina junghuhniana Miq root samples were collected from the State Forestry Research Institute, Neyveli, Tamil Nadu. Isolation of fungal endophyte was carried out using Potato Dextrose Agar medium. The qualitative and quantitative phytochemicals screening and enzyme assays were carried out using standard procedures. Antimicrobial assay was tested against different pathogens using well diffusion method. Further, the phytochemicals in the root extract was evaluated using FTIR, HPLC and GC MS studies.Result: Among the isolated endophytes, the dominant isolate (CJN5) was identified as Aspergillus sp which showed positive result in the production of industrially important enzymes, namely, cellulase, lipase and amylase The qualitative screening revealed the presence of various phytoconstituents Total phenolic content of CFE (208.20±2 mg/g) was found higher than CME(165.5±3mg/g). The total flavonoid content of CFE (25.95±2 mg/g) was also found higher than CME (3.59±2 mg/g) using respective standards. Antimicrobial activity showed maximum zone of inhibition against Pseudomonas aeruginosa (bacterial pathogen) (24±0.1cm) and Fusarium oxysporum (fungal phytopathogen) (34 ± 0.2cm).FTIR analysis showed the presence of varied functional groups. HPLC study revealed the presence of Gallic acid acid and Salicylic acid. Several peaks were obtained in GCMS analysis which indicates the presence of different secondary metabolites.Conclusion: Aspergillus sp, isolated from the root of Casuarina junghuhniana Miq is a promising source of bioactive compounds which can be utilised in agriculture and pharmaceutical industries.Key words: endophyte, Casuarina junghuhniana, phytochemical, antimicrobial, HPLC, GC MS

The root endophytic fungus Curvularia geniculata from Parthenium hysterophorus roots improves plant growth through phosphate solubilization and phytohormone production

The plant growth promoting ability of Curvularia geniculata (Tracy & Earle) Boedijn, a dark septate endophyte (DSE) fungus isolated from Parthenium hysterophorus L., was examined under in-vitro conditions for the first time. The abilities of the fungus to solubilize different sources of phosphorus (P) [AlPO4, FePO4 and Ca3(PO4)2] and to produce indole acetic acid (IAA) were also determined. C. geniculata-inoculated pigeon pea (Cajanus cajan) plants exhibited superior growth over uninoculated control plants and the fungus solubilized different sources of P in the order of FePO4>AlPO4>Ca3(PO4)2. The pH of the culture medium, fungal biomass production and acid phosphatase activity was significantly influenced by phosphate source and incubation period. IAA production, confirmed by chromatographic analysis, increased with increasing concentrations of tryptophan in a non-linear manner. It can be concluded from the results that C. geniculata mediates plant growth through phosphate solubilization and phytohormone production. This would enable the use of this fungus as bioinoculant in plant production systems.

Invisible but consequential: root endophytic fungi have variable effects on belowground plant–insect interactions

AbstractEndophytic fungi are ubiquitous in nature and can play important roles in regulating plant–herbivore interactions. While some aboveground obligate symbionts are considered defensive mutualists of host plants, the importance of root endophytes in plant defense, especially against root‐feeding insects, remains unclear. This study aimed to investigate the effects of root fungal endophytes on plant resistance against belowground herbivores and the recovery of host plants from damage. We grew the common grassFestuca arundinacea(tall fescue) semi‐aeroponically in the laboratory and inoculated roots with one of five fungal endophytes isolated from field‐collected tall fescue or meadow soil. Endophyte‐inoculated and uninoculated control plants were subjected to feeding by larvae of the generalist root herbivoreRhizotrogus majalis(European chafer). Herbivory intensity was quantified after eight days, and regrowth of roots and shoots following root herbivory and mechanical shoot damage was measured thereafter for each treatment. Fungal identifications byDNAsequence analysis were conducted after completion of the herbivory experiments and revealed that the five endophytes included the decomposer fungiTrametes versicolorandMortierella alpina, the entomopathogenic fungiIsaria fumosoroseaandBeauveria bassiana, and a potential plant pathogen/entomopathogenFusariumcf.equiseti. The effects of these root endophytes on plant defense against root‐feeding insects were species‐specific. While four endophytes had few effects on plant resistance, endophyticB. bassianasignificantly reduced herbivore damage to roots. In comparison, plant tolerance to damage was impaired after colonization by all endophyte species exceptT. versicolorandM. alpina. The contrasting effects of endophytes on plant resistance and plant tolerance suggest that research solely evaluating plant resistance is likely to overestimate the benefits conferred by endophytes without accounting for potential negative effects on plant tolerance. We propose a conceptual framework to include both plant resistance and tolerance as two dimensions of a defensive strategy and show that plant associations with different root endophytes may shift the relative importance of resistance and tolerance for plant defense.

New root endophytic water borne conidial fungi from Kumaun Himalaya

<p>Water borne conidial fungi occurring in living roots of healthy plant growing in the wet and ravine areas of Dogaon and Ramgarh, Nainital, Kumaun Himalaya (India) were isolated as root endophytes. A total of 15 species (<em>Alatospora acuminata, Anguillospora longissima, Beltrania rhombica</em>,<em> Campylospora chaetocladia, Claviriopsis aquatica, Cylindrocarpon aquaticum, Flagellospora penicilloides, Helicomyces roseus, Helicosporium lumbricoides, Pleurophragmium sonum, Pestalotiopsis submersus, Seridium sp, Setosynnema isthomosporum, Tetrachaetum elegans </em>and<em> Tetracladium marchalianum</em>) of endophytic aquatic fungus were recovered as root endophytes of various host plants.<em> </em>Three species viz.<em> Helicosporium lumbricoides, Pleurophragmium sonum </em>and <em>Setosynnema isthomosporum </em>isolated from the roots of pteridophytes and grasses were found as new root endophytes. Among the studied host plants five plant species were also found as new hosts.</p>

Root-endophytic fungi cause morphological and functional differences in Scots pine roots in contrast to ectomycorrhizal fungi

Endophytic fungi and ectomycorrhizal fungi co-exist in the mycorrhizal root tips of boreal forest trees. However, very little is known about the functional role they play in their host’s biology. The activity of enzymes responsible for important biochemical processes is used to determine the functional role of root-associated mycorrhizal fungi. However, enzyme activity is never studied in the presence of endophytic fungi in-planta. The aims of this study were to investigate the effect of Scots pine (Pinus sylvestris L.) root-isolated fungal endophytes on the host plant root morphology, to determine their functional effects using host root-excreted enzyme activity measurements, and to compare them with roots colonized by decomposer and ectomycorrhizal fungal strains and noncolonised Scots pine root tips. Our results show that endophytic fungi did not damage the pine roots in contrast to the decomposer fungi. The endophytic fungi penetrated the cortical cells of the host plant. The roots colonised by endophytic fungi produce different exo-enzymes compared with those produced by roots colonized by other fungal groups or noncolonized control root tips. Our results indicate that endophytic fungi are clearly a distinctive ecological group of fungi that have functional traits different from those of ectomycorrhizal and decomposer fungi.

Nutrient Concentration in Growth Medium Affects Relationship between Root Endophytic Fungi and Host Plant

Nutrient Concentration in Growth Medium Affects Relationship between Root Endophytic Fungi and Host Plant

Molecular characterization of endophytic fungi associated with the roots of Chenopodium quinoa inhabiting the Atacama Desert, Chile

Plant roots can be highly colonized by fungal endophytes. This seems to be of particular importance for the survival of plants inhabiting stressful habitats. This study focused on the Identification of the fungal endophytic community associated with the roots of quinoa plants (Chenopodium quinoa) growing near the salt lakes of the Atacama Desert, Chile. One hundred endophytic fungi were isolated from healthy quinoa roots, and the internal transcribed spacer (ITS) region was sequenced for phylogenetic and taxonomic analysis. The isolates were classified into eleven genera and 21 distinct operational taxonomic units (OTUs). Despite a relatively high diversity of root endophytic fungi associated with quinoa plants, the fungal community was dominated by only the Ascomycota phyla. In addition, the most abundant genera were Penicillium, Phoma and Fusarium, which are common endophytes reported in plant roots. This study shows that roots of C. quinoa harbor a diverse group of endophytic fungi. Potential roles of these fungi in plant host tolerance to stressful conditions are discussed.

In vitro antagonistic activity of a root endophytic fungus towards plant pathogenic fungi

In vitro antagonistic activity of a root endophytic fungus towards plant pathogenic fungi

Beneficial root endophytic fungi change growth and oil composition of sweet basil in heavy metal contaminated soil

Beneficial root endophytic fungi change growth and oil composition of sweet basil in heavy metal contaminated soil

Root Fungal Endophytes Enhance Heavy-Metal Stress Tolerance of Clethra barbinervis Growing Naturally at Mining Sites via Growth Enhancement, Promotion of Nutrient Uptake and Decrease of Heavy-Metal Concentration.

Clethra barbinervis Sieb. et Zucc. is a tree species that grows naturally at several mine sites and seems to be tolerant of high concentrations of heavy metals, such as Cu, Zn, and Pb. The purpose of this study is to clarify the mechanism(s) underlying this species’ ability to tolerate the sites’ severe heavy-metal pollution by considering C. barbinervis interaction with root fungal endophytes. We measured the heavy metal concentrations of root-zone soil, leaves, branches, and fine roots collected from mature C. barbinervis at Hitachi mine. We isolated fungal endophytes from surface-sterilized root segments, and we examined the growth, and heavy metal and nutrient absorption of C. barbinervis seedlings growing in sterilized mine soil with or without root fungal endophytes. Field analyses showed that C. barbinervis contained considerably high amounts of Cu, Zn, and Pb in fine roots and Zn in leaves. The fungi, Phialocephala fortinii, Rhizodermea veluwensis, and Rhizoscyphus sp. were frequently isolated as dominant fungal endophyte species. Inoculation of these root fungal endophytes to C. barbinervis seedlings growing in sterilized mine soil indicated that these fungi significantly enhanced the growth of C. barbinervis seedlings, increased K uptake in shoots and reduced the concentrations of Cu, Ni, Zn, Cd, and Pb in roots. Without root fungal endophytes, C. barbinervis could hardly grow under the heavy-metal contaminated condition, showing chlorosis, a symptom of heavy-metal toxicity. Our results indicate that the tree C. barbinervis can tolerate high heavy-metal concentrations due to the support of root fungal endophytes including P. fortinii, R. veluwensis, and Rhizoscyphus sp. via growth enhancement, K uptake promotion and decrease of heavy metal concentrations.

Wheat biochemical response to cadmium toxicity under Funneliformis mosseae and Piriformospora indica symbiosis / Kviečių, esančių simbiozėje su Funneliformis mosseae ir Piriformospora indica, biocheminis atsakas į kadmio toksinį poveikį

AbstractThe effects of root endophytic fungus Piriformospora indica and arbuscular mycorrhizal fungus Funneliformis mosseae were investigated on some biochemical parameters in leaves and roots of Triticum aestivum cv. ‘Sardari39’ under Cadmium (Cd) stress. The experiment was carried out with inoculation treatments of F. mosseae, P. indica, F. mosseae + P. indica and no-inoculation (control) at four Cd concentrations (0, 0.3, 0.6 and 0.9 mM Cd). The results revealed that in non-inoculated plants, H2O2, malondialdehyde (MDA) and proline contents increased in leaves and roots in response to increasing soil Cd concentrations. However, guaiacol peroxidase (GPX) activity in roots and superoxide dismutase (SOD) activity in leaves and roots increased at lower Cd concentrations, while at higher Cd concentrations the rate decreased. In the presence of P. indica and F. mosseae + P. indica, H2O2and MDA contents decreased, and proline accumulation increased in wheat leaves and roots. Also, the presence of P. indica increased GPX and SOD activities in leaves and roots. The study concluded that P. indica and F. mosseae were able to maintain an efficient symbiosis with wheat plants in soil at high Cd concentrations. However, the impact of P. indica in alleviating Cd stress was more noticeable than that of F. mosseae.

Contracting montane cloud forests: a case study of the Andean alder (Alnus acuminata) and associated fungi in the Yungas

AbstractAlnus acuminata is a keystone tree species in the Yungas forests and host to a wide range of fungal symbionts. While species distribution models (SDMs) are routinely used for plants and animals to study the effects of climate change on montane forest communities, employing SDMs in fungi has been hindered by the lack of data on their geographic distribution. The well‐known host specificity and common biogeographic history of A. acuminata and associated ectomycorrhizal (ECM) fungi provide an exceptional opportunity to model the potential habitat for this symbiotic assemblage and to predict possible climate‐driven changes in the future. We (1) modeled the present and future distributions of suitable habitats for A. acuminata; (2) characterized fungal communities in different altitudinal zones of the Yungas using DNA metabarcoding of soil and root samples; and (3) selected fungi that were significant indicators of Alnus. Fungal communities were strongly structured according to altitudinal forest types and the presence of Alnus. Fungal indicators of Alnus, particularly ECM and root endophytic fungi, were also detected in Alnus roots. Current and future (year 2050) habitat models developed for A. acuminata predict a 25–50 percent decrease in suitable area and an upslope shift of the suitable habitat by ca. 184–380 m, depending on the climate change scenario. Although A. acuminata is considered to be an effective disperser, recent studies suggest that Andean grasslands are remarkably resistant to forest invasion, and future range contraction for A. acuminata may be even more pronounced than predicted by our models.

Low diversity and abundance of root endophytes prevail throughout the life cycle of an annual halophyte

Plants growing in highly saline soils harbor unique communities of fungal root endophytes. We aimed to gain insight into how these communities are established in natural plant populations. We used cultivation-based and molecular approaches to examine root-endophytic colonization in the annual halophyte Salicornia patula at three time points over a 5-month period, from establishment to flowering. At the last sampling, the endophytic community of S. patula was compared to that in the related but perennial halophyte Arthrocnemum macrostachyum. The presence of root endophytes in S. patula was negligible at the first two sampling times, and remained low at the last sampling compared to A. macrostachyum. The latter species showed a well-established endophytic community in its roots that differed from that in S. patula, which was dominated by members of Pleosporales. Although such differences could be partially due to the host lifestyle, the possibility of a strong effect of the substratum could not be excluded. Altogether, our data indicate that the fungal endophytic colonization of roots is a slow process under salt stress. Therefore, we suggest that, in contrast to what is proposed for other systems, endophyte symbioses are unlikely to impact the development of the short-life-cycled S. patula living in these environments.

Influence of phylogenetic conservatism and trait convergence on the interactions between fungal root endophytes and plants.

Plants associate through their roots with fungal assemblages that impact their abundance and productivity. Non-mycorrhizal endophytes constitute an important component of such fungal diversity, but their implication in ecosystem processes is little known. Using a selection of 128 root-endophytic strains, we defined functional groups based on their traits and plant interactions with potential to predict community assembly and symbiotic association processes. In vitro tests of the strains' interactions with Arabidopsis thaliana, Microthlaspi erraticum and Hordeum vulgare showed a net negative effect of fungal colonization on plant growth. The effects partly depended on the phylogenetic affiliation of strains, but also varied considerably depending on the plant-strain combination. The variation was partly explained by fungal traits shared by different lineages, like growth rates or melanization. The origin of strains also affected their symbioses, with endophytes isolated from Microthlaspi spp. populations being more detrimental to M. erraticum than strains from other sources. Our findings suggest that plant-endophyte associations are subject to local processes of selection, in which particular combinations of symbionts are favored across landscapes. We also show that different common endophytic taxa have differential sets of traits found to affect interactions, hinting to a functional complementarity that can explain their frequent co-existence in natural communities.

Potential ecological effects of Piriformospora indica, a possible biocontrol agent, in UK agricultural systems

Piriformospora indica (syn. Serendipita indica), a root endophytic fungus, was originally isolated from an arid sub-tropical soil. P. indica forms mutualistic symbioses with a broad range of host plants, increases biomass production, resistance and tolerance to fungal pathogens and abiotic stresses. These characteristics make it a very attractive component of more sustainable agriculture. So, it is desirable to understand its wider ecosystem effects. We determined how long P. indica could survive in the soil and how it interacts with other soil microorganisms and some important arable weeds.Survival of P. indica in the soil, under winter and summer conditions in the UK was tested by isolating DNA and RNA of P. indica from pots of soil which had been left open to winter-summer weather conditions without host plants, followed by PCR and reverse transcription-PCR (RT-PCR) with P. indica-specific primers. P. indica effects on other soil and root microorganisms were tested by PCR-denaturing gradient gel electrophoresis analysis of DNA extracted from soil and roots from pots in which P. indica-infected wheat had been grown. The effect of P. indica on growth of black-grass (Alopecurus myosuroides), wild-oat (Avena fatua) and cleavers (Galium aparine) was tested alone and in competition with wheat.In soil P. indica-mRNA and DNA could still be detected after eight months, but not after 15months. Soils from P. indica-inoculated pots had distinct fungal and bacterial species communities which were more diverse than non-inoculated controls. P. indica infected A. myosuroides and A. fatua but was not detected in G. aparine. The average above-ground competitiveness of the weeds with wheat was decreased.If applied to field crops in the UK, P. indica would be persistent for up to 15months and likely to alter competitive relations within vegetation. Increased soil microbial diversity during the first eight weeks after inoculation, although usually desirable, could alter soil composition or functioning.

Effect of different root endophytic fungi on plant community structure in experimental microcosms.

Understanding the effects of root‐associated microbes in explaining plant community patterns represents a challenge in community ecology. Although typically overlooked, several lines of evidence point out that nonmycorrhizal, root endophytic fungi in the Ascomycota may have the potential to drive changes in plant community ecology given their ubiquitous presence, wide host ranges, and plant species‐specific fitness effects. Thus, we experimentally manipulated the presence of root endophytic fungal species in microcosms and measured its effects on plant communities. Specifically, we tested whether (1) three different root endophyte species can modify plant community structure; (2) those changes can also modified the way plant respond to different soil types; and (3) the effects are modified when all the fungi are present. As a model system, we used plant and fungal species that naturally co‐occur in a temperate grassland. Further, the soil types used in our experiment reflected a strong gradient in soil texture that has been shown to drive changes in plant and fungal community structure in the field. Results showed that each plant species responded differently to infection, resulting in distinct patterns of plant community structure depending on the identity of the fungus present. Those effects depended on the soil type. For example, large positive effects due to presence of the fungi were able to compensate for less nutrients levels in one soil type. Further, host responses when all three fungi were present were different from the ones observed in single fungal inoculations, suggesting that endophyte–endophyte interactions may be important in structuring plant communities. Overall, these results indicate that plant responses to changes in the species identity of nonmycorrhizal fungal community species and their interactions can modify plant community structure.

Rhizospheric soil and root endogenous fungal diversity and composition in response to continuous Panax notoginseng cropping practices

Rhizosphere and endophytic fungal communities are considered critically important for plant health and soil fertility. In response to continuous cropping, Panax notoginseng becomes vulnerable to attack by fungal pathogens. In the present study, culture-independent Illumina MiSeq was used to investigate the rhizospheric and root endophytic fungi in response to continuous Panax notoginseng cropping practices. The results demonstrated that fungal diversity is increased inside the roots and in rhizospheric. Ascomycota, Zygomycota, Basidiomycota and Chytridiomycota were the dominant phyla detected during the continuous cropping of Panax notoginseng. The fungal diversity in the rhizospheric soil and roots of root-rot P. notoginseng plants are less than that of healthy plants in the same cultivating year, thus showing that root-rot disease also affects the community structure and diversity of rhizospheric and root endophytic fungi. Similarities in the major fungal components show that endophytic fungal communities are similar to rhizospheric soil fungal community based on a specialized subset of organisms. Canonical correspondence analysis on the fungal communities in root-rot rhizospheric from both healthy plants and rotation soils reveals that the soil pH and organic matter have the greatest impact upon the microbial community composition during continuous cropping, whereas soil nutrition status does not significantly affect the fungal community composition in response to continuous cropping practices. In addition, the results suggest that the unclassified genera Leotiomycetes, Cylindrocarpon, Fusarium and Mycocentrospora are shown as the potential pathogens which are responsible for the obstacles in continuous cropping of P. notoginseng. Further exploration of these potential pathogens might be useful for the biological control of continuous cropping of P. notoginseng.