Diversity Of Culturable Endophytic Fungi Research Articles

Diversity of culturable endophytic fungi vary through time in Manihot esculenta Crantz.

Endophytic fungi are a ubiquituos group that colonize all plant species on earth. Studies comparing the location of endophytic fungi within the leaves and the sampling time in Manihot esculenta Crantz (cassava) are limited. In this study, mature leaves of M. esculenta from Panama were collected in order to compare the cultivable diversity of endophytic fungi and to determine their distribution within the leaves. A total of one hundred sixty endophytes belonging to 97 species representing 13 genera and 8 morphospecies determined as mycelia sterilia that containing 63 isolates were isolated. Cladosporium, Nigrospora, Periconia, and mycelia sterilia 1 and 3 were the most predominant isolated endophytes. We detected that endophytes varied across the sampling time, but not amongst locations within leaves. The endophytes composition across sampling and the location of endophytes within leaf was similar, except for Periconia and mycelia sterilia 3 and 7. The data generated in this study contribute to the knowledge on the biodiversity of endophytic fungi in Panama, and establish the bases for future research focused on understanding the function of endophytes in M. esculenta crops.

Diversity of Culturable Endophytic Fungi in Crocus sativus and Their Correlation with Crocin Content.

The presence and diversity of endophytic fungi associated with host plants are important not just for host plant growth and defense, but also impact the production of medicinal secondary metabolites. However, the correlation between endophytic fungi and crocin production in Crocus sativus (CS) remains underexplored. Here, we explore the relationship between endophytic fungal diversity and crocin content among different CS tissues and field sites. Specifically, we isolated endophytic fungi from five different field sites (Shanghai, Jiande, Huzhou, Anhui, and Hebei) and five different tissues (corm, scape, leaf, petal, and stigma) and analyzed fungal community diversity, richness, and evenness. We identified a total of 32 endophytic fungal taxa, assigned to 7 orders within 4 classes (Eurotiomycetes, Agaricomycetes, Dothideomycetes, and Sordariomycetes). The most dominant order was Eurotiales, and the most dominant genera were Penicillium and Talaromyces. Species richness tended to be highest in belowgrown tissues, such as corm and scape. Additionally, several fungal taxa were found to be either site- or tissue-specific. Three genera in particular were correlated with crocin content: Penicillium, Sistotrema, and Bjerkandera. Given the fact that endophytic microorganisms can both promote the production of secondary metabolites in host plants and potentially produce secondary metabolites themselves, further study is required to understand the mechanistic relationship between these and other fungal genera and crocin production.

Culturable Endophytic Fungi in Fraxinus excelsior and Their Interactions with Hymenoscyphus fraxineus

The species diversity of culturable endophytic fungi was studied in the leaves and twigs of symptomatic and asymptomatic Fraxinus excelsior trees. Endophytic mycobiota was dominated by Ascomycota species, with Pleosporales (44.17%) and Diaporthales (23.79%) endophytes being the most frequently observed in the tree samples. The number of endophytic isolates and species richness varied depending on the sampling date (May and October) and tissue location. Of the 54 species identified based on ITS sequences, 14 were classified as dominant. The most frequently isolated species were Diaporthe eres, followed by Alternaria alternata, Dothiorella gregaria, and Fraxinicola fraxini. The inhibitory effect of 41 species (75 isolates) of endophytes on the radial growth of a Hymenoscyphus fraxineus isolate was studied under in vitro conditions (dual cultures). The radial growth of H. fraxineus was the most inhibited by four endophytic fungi from twigs (Fusarium lateritium, Didymella aliena, Didymella macrostoma, and Dothiorella gregaria). The inhibitory effect of the four isolates was also studied under in planta conditions. The isolates artificially inoculated into the trunks of ash trees reduced the length of necroses formed by H. fraxineus co-inoculated in the same trunks. This effect depended on the isolate, and the inhibition was most prominent only on trunks inoculated with F. lateritium and D. aliena. Although the total length of necrotic lesions formed by the H. fraxineus infection was shorter in the ash trunks co-inoculated with the endophytes, the difference was not significant.

Diversity and communities of culturable endophytic fungi from the root holoparasite Balanophora polyandra Griff. and their antibacterial and antioxidant activities

PurposeBalanophora polyandra Griff. is a holoparasitic medicinal plant that produces compounds with antibacterial and antioxidant activities. Plant endophytic fungi are an abundant reservoir of bioactive metabolites for medicinal exploitation, and an increasing number of novel bioactive compounds are being isolated from endophytic fungi. The present study investigated the diversity of culturable endophytic fungi from the roots of holoparasite B. polyandra to explore active strains and metabolites. In addition, the antibacterial and antioxidant activities of 22 strains cultured from B. polyandra were also evaluated.MethodsThe endophytic fungi were identified according to their colony morphology and ITS-5.8S rDNA sequencing. TLC-MTT-Bioautography assays and DPPH radical scavenging assays were employed to assess the antibacterial and antioxidant activities of ethyl acetate extracts of the endophytic fungi.ResultsOne hundred and twenty-five endophytic strains were isolated from the roots of B. polyandra, including 70 from female samples and 55 from male samples. Of them, twenty-two distinct isolates representing 15 genera and 22 species based on their ITS-rDNA genomic sequence were successfully identified from female and male samples of B. polyandra. The genus Calonectria was the most prevalent genus, with a CF% of 18.3, followed by the genera Clonostachys and Botryosphaeria, with CF% values of 13.4 and 10.0, respectively. Interestingly, the fungal extracts exhibited broad-spectrum antibacterial activities against gram-positive and gram-negative bacteria, as well as potential antioxidant activities with IC50 values ranging from 0.45 to 6.90 mg/mL. Among them, endophytes Bpf-10 (Diaporthe sp.) and Bpf-11 (Botryosphaeria sp.) showed the strongest biological activities and more abundant secondary metabolites.ConclusionsThis study reported the diversity of endophytic fungi from the roots of B. polyandra and the antibacterial and antioxidant activities of the crude extracts for the first time. The results revealed that B. polyandra contains diverse culturable endophytic fungi that potentially produce natural antibacterial and antioxidant compounds with great value to the agriculture and pharmaceutical industries.

Soil Fungal Community Composition and Diversity of Culturable Endophytic Fungi from Plant Roots in the Reclaimed Area of the Eastern Coast of China.

As an important resource for screening microbial strains capable of conferring stress tolerance in plants, the fungal community associated with the plants grown in stressful environments has received great attention. In this study, high-throughput sequencing was employed to study the rhizosphere fungal community in the reclaimed area (i.e., sites F, H, and T) of the eastern coast of China. Moreover, endophytic fungi from the root of six plant species colonizing the investigated sites were isolated and identified. The differences in soil physicochemical parameters, fungal diversity, and community structure were detected among the sampling sites and between the seasons. Ectomycorrhizal (ECM) fungi (e.g., genera Tuber and Geopora) were dominant at site F, which was characterized by high soil total carbon (SC) and total nitrogen (SN) contents and low soil electrical conductivity (EC) value. Arbuscular mycorrhizal (AM) fungi, including genera Glomus, Rhizophagus, and Entrophospora were dominant at sites H (winter), H (summer), and T (summer), respectively. The positive relationship between the EC value and the abundance of genus Glomus indicated the ability of this AM fungus to protect plants against the salt stress. Endophytic fungi at sites F (Aspergillus and Tetracladium), H (Nigrospora), and T (Nigrospora, Coniochaeta and Zopfiella) were recognized as the biomarkers or keystone taxa, among which only genus Aspergillus was isolated from the plant roots. The aforementioned AM fungi and endophytic fungi could contribute to the promotion of plant growth in the newly reclaimed land.

Culturable Endophytic Fungi from Glycyrrhiza inflata Distributed in Xinjiang, China with Antifungal Activity

A total of 99 endophytic fungal isolates were obtained from the roots of Glycyrrhiza inflata, which was a traditional medicinal plant mainly distributed in Xinjiang, China. Twenty-two distinct isolates were selected for further taxonomical identification by morphological traits and internal transcribed spacer (ITS) rRNA gene sequence analysis. Eleven genera were identified, among which Aspergillus, Alternaria and Fusarium were dominant. The crude extracts of 22 distinct identified fungi were successively evaluated for their antifungal activities on three rice fungal pathogens using the method of hyphal radial growth rate. Among them, the crude extract of Alternaria an-gustiovoidea Glinf007 showed the significantly mycelial growth inhibitory activity. The results demonstrated that G. inflata contained a diversity of culturable endophytic fungi, which could produce natural antimicrobial compounds that might be of great value to the agriculture and pharmaceutical industries.

Diversity of endophytic fungal species from Styrax benzoin found in benzoin-producing locations in North Sumatra

Styrax benzoin is a native tree to Indonesia, particularly in North Sumatra. This plant species produces benzoin resin, which is beneficial for medicinal treatments, hence its commercial value. Endophytic fungi help produce bioactive metabolites and contribute to resin production. However, the diversity of endophytic fungal species from S. benzoin grown in North Sumatra remained largely unexplored. This study aims to determine the distribution and diversity of culturable endophytic fungi from two kemenyan-producing locations in North Sumatra, Simalungun and North Tapanuli, as well as their tree part origin. A total of 7 and 8 endophytic fungal species were obtained from barks, stems, and/or leaves of S. benzoin grown in Simalungun and North Tapanuli, respectively, and identified by internal transcribed spacer sequence analysis. Endophytic fungi from North Tapanuli showed higher diversity, with a Shannon-Wiener index of 2.31 than those from Simalungun (1.95). Morisita-Horn similarity indices for bark-stem, stem-leaf, and bark-leaf were 0.47, 0.08, and 0, respectively, hinting at organ-specificity colonization. This study offers insights into the diversity of endophytic fungi isolated from S. benzoin which may contribute to future improvement of benzoin resin production.

Diversity of endophytic fungi isolated from benzoin-producing tree Styrax sumatrana

Styrax sumatrana, native to Sumatra island, Indonesia, is distinctive for its production of benzoin resin. The resin is used for medicinal treatments and commercially valuable. Fungal endophytes are known to produce various bioactive metabolites and may contribute to host resin production or properties. However, the diversity of culturable endophytic fungi associated with S. sumatrana were still underexplored. This study was conducted to examine the distribution and diversity of culturable endophytic fungi associated with tree parts; bark, stem, and leaves of S. sumatrana. A total of 31 endophytic fungi isolates were obtained from S. sumatrana grown in North Sumatera Province, from which 10 genera and 17 species were identified by internal transcribed spacer (ITS) sequence analyses. Among 31 isolates, Fusarium, Phyllostica, Neopestalotiopsis and Pestaliopsis were repeatedly isolated. The species richness S (10), Margalef index D’ (3.323), Shannon–Wiener index H’ (1.587), and Simpson diversity index Ds (0.756) and low dominant index λ (0.244) of endophytic fungi in the bark of S. sumatrana indicated its high diversity in comparison to other parts of the tree. This finding provides a knowledge of the diversity and organ-type-specificity of endophytic fungal that could be used for biotechnological application in the future.

Diversity and antimicrobial activity of endophytic fungi isolated from Securinega suffruticosa in the Yellow River Delta.

Securinega suffruticosa (Pall.) Rehd is an excellent natural secondary shrub in the Shell Islands of Yellow River Delta. The roots of S. suffruticosa have high medicinal value and are used to treat diseases, such as neurasthenia and infant malnutrition. Any organism that is isolated from this species is of immense interest due to its potential novel bioactive compounds. In this research, the distribution and diversity of culturable endophytic fungi in S. suffruticosa were studied, and the endophytic fungi with antimicrobial activity were screened. A total of 420 endophytic fungi isolates were obtained from the S. suffruticosa grown in Shell Islands, from which 20 genera and 35 species were identified through morphological and internal transcribed spacer (ITS) sequence analyses. Chaetomium, Fusarium, Cladosporium, and Ceratobasidium were the dominant genera. The high species richness S (42), Margalef index D' (5.6289), Shannon-Wiener index H' (3.1000), Simpson diversity index Ds (0.9459), PIE index (0.8670), and evenness Pielou index J (0.8719) and a low dominant index λ (0.0541) indicated the high diversity of endophytic fungi in S. suffruticosa, the various species of endophytic fungi with obvious tissue specificity. The inhibition percentages of the 12 species of such endophytic fungi against Colletotrichum siamense were 3.6%-26.3%. C. globosum, Fusarium sp.3, and C. ramotenellum had a high antibacterial activity against Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal Concentration (MBC) were between 0.5 mg/mL and 2 mg/mL. Alkaloid content detection indicated that endophytic fungi had a high alkaloid content, whereas the alkaloid contents of C. globosum and Fusarium sp.3 reached 0.231% and 0.170%, respectively. Members belonging to the endophytic fungal community in the S. suffruticosa of Shell Islands that may be used as antagonists and antibacterial agents for future biotechnology applications were identified for the first time.

Assessment of Endophytic Fungi Associated with Greavillea Robusta Tree Planted as Urban Green Infrastructure in Hawassa Town: Its Implication to Understand the Current Health Condition of Urban trees

Endophytic fungi represent a genetically diverse group of microorganisms associated with healthy tissues of terrestrial plants. They are believed to be mostly beneficial to their host plants and produce novel antimicrobial compounds or may be latent pathogens that become active at specific stage of development or under a set of environmental conditions. The aim of the current study was to assess the diversity of culturable endophytic fungi in the leaf of diseased and healthy looking Grevillea robusta from different streets having different traffic flow. Leaf samples of G.robusta were collected from those trees growing in the road side, parks and home gardens at Hawassa town. Identification of the isolates to the genus level was performed on the basis of cultural characteristics and spore morphology. Accordingly, a total of 387 endophytic fungal isolates were recovered from 192 leaf fragments across five different streets. The highest isolation rate of endophytic fungi was recorded on a street from South Star Hotel to Bus station (IR=3.81) where as the smallest isolation rate was recorded on a street from Bus station to Atote (IR=0.71). The highest relative frequency of endophytic fungi was recorded for Pestalotiopsis spp 2 (RF=25.58%) where as the smallest was recorded was recorded for Unidentified spp 5 (RF=0.51%). Additionally, the highest diversity of endophytic fungi was recorded on the road from South Star Hotel to Bus station (H’=3.01) where as the smallest diversity of endophytic fungi was recorded on a street from Atote to Teachers Teaching College (H’=1.79). Keywords: - Disease, Urban trees, Diversity, Grevillea robusta DOI : 10.7176/ALST/77-04 Publication date: January 31 st 2020

Are endophytic fungi from Rhododendron tomentosum preadapted for its essential oil?

Endophytic fungi have to cope with various secondary metabolites produced by their host plant. Rhododendron tomentosum is an evergreen shrub with a high content of essential oil showing antimicrobial effects. The first aim of our study was to reveal the diversity of culturable endophytic fungi colonizing leaves of R. tomentosum. We isolated and identified 30 species, mostly ubiquitous species colonizing various plants as endophytes and later turning into saprotrophs. The second aim was to explore whether strains obtained from R. tomentosum (RT-strain) are better adapted to growth in environments with essential oils, compared to strains of the same species obtained from different substrates. In five of the six species pairs tested, the growth of RT-strains was more inhibited by three components of the essential oil added to the medium, compared to the corresponding strains. Only the RT-strain of Desmazierella acicola was less susceptible compared to its corresponding strain. Our results show that the essential oil in leaves of R. tomentosum do not represent a selective barrier that can be crossed only by preadapted strains.

Diversity of culturable endophytic fungi of common reed (Phragmites australis) in coastal wetland.

Endophytic fungi play an important ecological role in promoting growth and alleviating environmental stress of host plants. In this study, we investigated the diversity and community composition of endophytic fungi isolated from the common reed in wetlands of the Yellow River Delta. A total of 318 endophytic fungal isolates were obtained from 1350 tissue (leaf, stem, and root) fragments and from three tidal zones with different soil salinity levels. rDNA ITS regions of these isolates were PCR amplified, sequenced, and phylogenetically analyzed. All the sequences were divided into 12 operational taxonomic units (OTUs) at the 98% similarity threshold. Ascomycota was found to be the most abundant flora at the level of the phylum and distributed in all tissues and sites. There were generally richer OTUs in roots than in leaves and stems, and leaves and stems shared the same OTU numbers. All the OTUs retrieved from leaves appeared in roots. The supra tide (low salinity zone) had the most OTUs among the three sampling sites, followed by high tide. Furthermore, the roots had the highest richness and diversity, whereas the leaves had the lowest; supra tide held the highest richness, and the middle tide had the highest diversity. Although unique OTUs could be found in different tissues and tidal zones of different salinity, the communities of culturable endophytic fungi were not substantially different among tissues or tidal zones (ANOSIM, P>0.05). Alternaria sp. was the shared dominant taxa among all samples.

Phylogenetic diversity of culturable endophytic fungi in Dongxiang wild rice (Oryza rufipogon Griff), detection of polyketide synthase gene and their antagonistic activity analysis

The biodiversity of plant endophytic fungi is enormous, numerous competent endophytic fungi are capable of providing different forms of fitness benefits to host plants and also could produce a wide array of bioactive natural products, which make them a largely unexplored source of novel compounds with potential bioactivity. In this study, we provided a first insights into revealing the diversity of culturable endophytic fungi in Dongxiang wild rice (Oryza rufipogon Griff.) from China using rDNA-ITS phylogenetic analysis. Here, the potential of fungi in producing bioactive natural products was estimated based on the beta-ketosynthase detected in the polyketide synthase (PKS) gene cluster and on the bioassay of antagonistic activity against two rice phytopathogens Thanatephorus cucumeris and Xanthomonas oryzae. A total of 229 endophytic fungal strains were validated in 19 genera. Among the 24 representative strains, 13 strains displayedantagonistic activity against the phytopathogens. Furthermore, PKS genes were detected in 9 strains, indicating their potential for synthesising PKS compounds. Our study confirms the phylogenetic diversity of endophytic fungi in O. rufipogon G. and highlights that endophytic fungi are not only promising resources of biocontrol agents against phytopathogens of rice plants, but also of bioactive natural products and defensive secondary metabolites.

English

The aim of the current study was to investigate the effect of variation in land use, age of host tree, season and geographic location on the diversity of culturable endophytic fungi of needles of Afrocarpus falcatus. Endophytic fungi represent a genetically diverse group of microorganisms associated with healthy tissues of terrestrial plants. They are believed to be mostly beneficial to their host plants and produce novel antimicrobial compounds; or may be latent pathogens that become active at specific stage of development or under a set of environmental conditions. Wondo Genet and Menagesha Suba were the two geographic locations with differing altitudinal and climatic features selected for sample collection. Needle samples were collected from old and young trees growing in natural forests and open lands during dry and wet seasons. Identification of the isolates to the genus level was performed on the basis of culture characteristics and spore morphology. A total of 687 endophytic fungal isolates were obtained and categorized into 64 morphotaxa. Fifty two (81.25%) of the morphotaxa were identified to 12 genera while 12 morphotaxa were left as unidentified. Thirty two (50%) of the morphotaxa were isolated only from the Wondo Genet site while only 3 (4.7%) were isolated from the Menagesha Suba site. The four most diverse genera were Cercosporella, Xylaria, Botryosphaeria and Pestalotiopsis. Phoma was the most abundantly represented genus followed by Xylaria and Pestalotiopsis while Trichotecium and Mycosphaerella were the rarest genera. The Wondo Genet site during the dry season was the most diverse (H’= 3.36649) and many of the morphotaxa were unique to the site; which might be ascribed to the differences in altitudinal, climatic and perhaps additional factors that were not considered in the current study. Key words: Fungal diversity, morphotaxa, Afrocarpus falcatus.

Species diversity of culturable endophytic fungi from Brazilian mangrove forests

This study aimed to perform a comparative analysis of the diversity of endophytic fungal communities isolated from the leaves and branches of Rhizophora mangle, Avicennia schaueriana and Laguncularia racemosa trees inhabiting two mangroves in the state of São Paulo, Brazil [Cananeia and Bertioga (oil spill-affected and unaffected)] in the summer and winter. Three hundred and forty-three fungi were identified by sequencing the ITS1-5.8S-ITS2 region of rDNA. Differences were observed in the frequencies of fungi isolated from the leaves and branches of these three different plant species sampled from the Bertioga oil spill-affected and the oil-unaffected mangrove sites in the summer and winter; these differences indicate a potential impact on fungal diversity in the study area due to the oil spill. The molecular identification of the fungi showed that the fungal community associated with these mangroves is composed of at least 34 different genera, the most frequent of which were Diaporthe, Colletotrichum, Fusarium, Trichoderma and Xylaria. The Shannon and the Chao1 indices [H'(95 %) = 4.00, H'(97 %) = 4.22, Chao1(95 %) = 204 and Chao1(97 %) = 603] indicated that the mangrove fungal community possesses a vast diversity and richness of endophytic fungi. The data generated in this study revealed a large reservoir of fungal genetic diversity inhabiting these Brazilian mangrove forests and highlighted substantial differences between the fungal communities associated with distinct plant tissues, plant species, impacted sites and sampling seasons.

Occurrence and diversity of endophytic fungi in Bletilla ochracea (Orchidaceae) in Guizhou, China

Previous studies regarding fungal specificity and diversity of the Orchidaceae mainly focus on the mycorrhizal fungi. In contrast, little knowledge of endophytic communities and distributions of non-mycorrhizal fungi in different organs and different sites of orchidsare available. In the present study, we investigated the occurrence and species diversity of culturable endophytic fungi from roots and leaves of terrestrial orchid Bletilla ochraceafrom 5 sites in Guizhou. A total of 1026 fungal strains were isolated, and identified to 88 taxa. The 7 species of Epulorhiza, Ceratorhiza and Sebacina (each with > 5% total relative frequency, Basidiomycetes), and 1 species of Phomopsis (6.38%, Ascomycetes) were found to be dominant in roots. In comparison, 5 species of Colletotrichum, Guignardia andCercospora (Ascomycetes) were dominant from leaves. Different species composition was found from different sites for both roots and leaves, and possible reasons are discussed. There was no or very few overlapping species found between roots and leavesin all sampling sites, indicating potential tissue specificity. The occurrence of fungal species from leaves was found to be significantly affected by geographic and environmental factors, and on the other hand, no significant correlation between fungal occurrence and geographic factors was found from roots. Key words: Ecological distribution, fungal community, identification, mycorrhizal fungi, Shannon-Wiener diversity index.

Endophytic fungal diversity in Theobroma cacao (cacao) and T. grandiflorum (cupuaçu) trees and their potential for growth promotion and biocontrol of black-pod disease

The endophytic niches of plants are a rich source of microbes that can directly and indirectly promote plant protection, growth and development. The diversity of culturable endophytic fungi from stems and branches of Theobroma cacao (cacao) and Theobroma grandiflorum (cupuaçu) trees growing in the Amazon region of Brazil was assessed. The collection of fungal endophytic isolates obtained was applied in field experiments to evaluate their potential as biocontrol agents against Phytophthora palmivora, the causal agent of the black-pod rot disease of cacao, one of the most important pathogens in cocoa-producing regions worldwide. The isolated endophytic fungi from 60 traditional, farmer-planted, healthy cacao and 10 cupuaçu plants were cultured in PDA under conditions inducing sporulation. Isolates were classified based upon the morphological characteristics of their cultures and reproductive structures. Spore suspensions from a total of 103 isolates that could be classified at least up to genus level were tested against P. palmivora in pods attached to cacao trees in the field. Results indicated that ∼70 % of isolates showed biocontrol effects to a certain extent, suggesting that culturable endophytic fungal biodiversity in this system is of a mostly mutualistic type of interaction with the host. Eight isolates from genera Trichoderma (reference isolate), Pestalotiopsis, Curvularia, Tolypocladium and Fusarium showed the highest level of activity against the pathogen, and were further characterized. All demonstrated their endophytic nature by colonizing axenic cacao plantlets, and confirmed their biocontrol activity on attached pods trials by showing significant decrease in disease severity in relation to the positive control. None, however, showed detectable growth-promotion effects. Aspects related to endophytic biodiversity and host–pathogen–endophyte interactions in the environment of this study were discussed on the context of developing sustainable strategies for biological control of black-pod rot of cacao.