Diversity of culturable endophytic fungi vary through time in Manihot esculenta Crantz / A diversidade de fungos endofíticos cultiváveis ​​varia ao longo do tempo em Manihot esculenta Crantz

Abstract 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.

Resumo Os fungos endofíticos são um grupo ubiquituo que colonizam todas as espécies de plantas na terra. Os estudos que comparam a localização dos fungos endofíticos dentro das folhas de Manihot esculenta Crantz (mandioca) e o tempo de amostragem são muito escassos. Neste estudo, folhas maduras de M. esculenta foram coletadas do Panamá com a finalidade de comparar a diversidade cultivável de endófitos e determinar sua distribuição dentro das folhas. Um total de 170 endófitos foram isolados de 97 espécies que representam 13 gêneros e 8 morfoespécies determinadas como micélios esterilizados contendo 63 isolados. Os fungos Cladosporium, Nigrospora, Periconia e mycelia sterilia 1 e 3 foram os isolados mais predominantes. Também detectamos que os endófitos variaram ao longo do tempo de amostragem, mas não entre os locais dentro das folhas. A composição de endófitos na amostragem e localização de endófitos dentro da folha foi semelhante, exceto para Periconia e mycelia sterilia 3 e 7. Os dados gerados neste estudo contribuem para o conhecimento da biodiversidade de fungos endofíticos no Panamá e estabelecem as bases para pesquisas sobre o entendimento da função de endófitos em culturas de M. esculenta.

Endophytic Bacillus subtilis P10 from Prunus cerasifera as a biocontrol agent against tomato Verticillium wilt / Bacillus subtilis P10 endofítico de Prunus cerasifera como agente de biocontrole contra murcha de Verticillium de tomate

Endophytic bacteria serve key roles in the maintenance of plant health and growth. Few studies to date, however, have explored the antagonistic and plant growth-promoting (PGP) properties of Prunus cerasifera endophytes. To that end, we isolated endophytic bacteria from P. cerasifera tissue samples and used a dual culture plate assay to screen these microbes for antagonistic activity against Verticillium dahliae, Botryosphaeria dothidea, Fusarium oxysporum, F. graminearum, and F. moniliforme. Of the 36 strains of isolated bacteria, four (strains P1, P10, P16, and P20) exhibited antagonistic effects against all five model pathogens, and the P10 strain exhibited the strongest antagonistic to five pathogens. This P10 strain was then characterized in-depth via phenotypic assessments, physiological analyses, and 16s rDNA sequencing, revealing it to be a strain of Bacillus subtilis. Application of a P10 cell suspension (1×108 CFU/mL) significantly enhanced the seed germination and seedling growth of tomato in a greenhouse setting. This P10 strain further significantly suppressed tomato Verticillium wilt with much lower disease incidence and disease index scores being observed following P10 treatment relative to untreated plants in pot-based experiments. Tomato plants that had been treated with strain P10 also enhanced defense-related enzymes, peroxidase, superoxide dismutase, and catalase activity upon V. dahliae challenge relative to plants that had not been treated with this endophytic bacterium. The results revealed that the P10 bacterial strain has potential value as a biocontrol agent for use in the prevention of tomato Verticillium wilt.

As bactérias endofíticas desempenham papel fundamental na manutenção da saúde e do crescimento das plantas. Poucos estudos até o momento, no entanto, exploraram as propriedades antagônicas e promotoras de crescimento de plantas (PGP) de endófitos de Prunus cerasifera. Para esse fim, isolamos bactérias endofíticas de amostras de tecido de P. cerasifera e usamos um ensaio de placa de cultura dupla para rastrear esses micróbios quanto à atividade antagonista contra Verticillium dahliae, Botryosphaeria dothidea, Fusarium oxysporum, F. graminearum e F. moniliforme. Das 36 cepas de bactérias isoladas, quatro (cepas P1, P10, P16 e P20) exibiram efeitos antagônicos contra todos os cinco patógenos modelo, e a cepa P10 exibiu o antagonista mais forte para cinco patógenos. Essa cepa P10 foi então caracterizada em profundidade por meio de avaliações fenotípicas, análises fisiológicas e sequenciamento de rDNA 16s, revelando ser uma cepa de Bacillus subtilis. A aplicação de uma suspensão de células P10 (1 × 108 UFC / mL) aumentou significativamente a germinação das sementes e o crescimento das mudas de tomate em casa de vegetação. Essa cepa P10 suprimiu ainda mais a murcha de Verticillium do tomate com incidência de doença muito menor e pontuações de índice de doença sendo observadas após o tratamento com P10 em relação a plantas não tratadas em experimentos baseados em vasos. As plantas de tomate que foram tratadas com a cepa P10 também aumentaram as enzimas relacionadas à defesa, peroxidase, superóxido dismutase e atividade da catalase após o desafio de V. dahliae em relação às plantas que não foram tratadas com essa bactéria endofítica. Os resultados revelaram que a cepa bacteriana P10 tem valor potencial como agente de biocontrole para uso na prevenção da murcha de Verticillium em tomate.

Endophytic bacteria Bacillus safensis and Pseudomonas hibiscicola and their ability to increase rice seedling growth

Endophytic bacteria Bacillus safensis RS95 and Pseudomonas hibiscicola RS121 were evaluated for their ability to promote the growth of rice seedlings and produce indole-acetic acid (IAA) and siderophores and to solubilize phosphates. 'Guri' rice seeds were immersed in bacterial endophyte cell suspensions (separated and two-strain mixed), as well as in Escherichia coli DH5α, phosphate-buffered saline (PBS) and water treatments (negative controls). Seeds were sown on agar-water in Petri plates placed vertically at an angle of 65°. The ability of plant growth-promoting endophytic bacteria (PGPEB) to produce IAA and siderophores was determined by Salkowski colorimetric and chrome azurol S (CAS) assays, respectively. Mineral phosphate solubilization activity was calculated by inoculating the endophytes onto medium containing insoluble phosphate. PGPEB showed a positive effect on the growth of rice seedlings, causing a mean growth of shoots and primary-roots of 60 and 67%, respectively. Bacterial strains also showed positive traits for IAA and siderophore production, as well as phosphate-solubilization activity

Secondary metabolites of endophyte fungi Xylaria sp. from Coptis chinensis / 中国中药杂志

Two new polyketides, lasobutone A(1) and lasobutone B(2), along with three known compounds, guignardianone C(3), guignardic acid(4), and 4-hydroxy-17R-methylincisterol(5), were isolated from the endophytic fungi Xylaria sp. by silica gel, MCI, and preparative HPLC, which was separated from the Chinese medicinal material Coptis chinensis and cultivated through solid fermentation with rice. Their structures were elucidated on the basis of spectroscopic methods, such as MS, NMR, IR, UV, and ECD. Compounds 2 and 4 showed inhibitory activities against the nitric oxide(NO) production in the LPS-induced macrophage RAW264.7 with IC_(50) values of 58.7 and 42.5 μmol·L~(-1) respectively, while compound 5 exhibited cytotoxic activities against HT-29 with IC_(50) value of 14.3 μmol·L~(-1).

Research progress and prospect of endophytes from medicinal plant Atractylodes lancea / 中国中药杂志

The endophytes of medicinal plants play an important role in promoting the quality formation of the host. Therefore, this paper made a review of endophytes of medicinal plant Atractylodes lancea. According to previous studies, A. lancea boasts endophytes, such as fungi, bacteria, and actinomycetes, among which the beneficial microorganisms help the growth and development of A. lancea. There is a close interaction between the volatile oil of A. lancea and endophytes. Different endophytes vary in regulating the composition and content of the volatile oil of A. lancea, which might contribute to the quality formation of A. lancea. However, the information of the endophytic flora of A. lancea obtained by traditional culture and isolation is not enough to reflect the real situation of the endophytes of A. lancea. Little is known about the endophytes of A. lancea from different chemical types and different habitats, which is not conducive to the study of the ecological relationship between A. lancea and endophytes and limits the development and utilization of the endophytes. Therefore, at the end of this paper, the authors put forward suggestions for future research on endophytes in A. lancea, including:(1)mining the core endophyte resources of A. lancea by combining high-throughput sequencing with traditional culture and isolation;(2)exploring the relationship between the diversity of endophytes and chemical types of A. lancea;(3)strengthening the application of endophytes in A. lancea cultivation, in order to facilitate the cultivation efficiency and quality of A. lancea.

Ornamental plant Pachystachys lutea as a source of promising endophytes for plant growth and phytoprotective activity

Endophytes are growth-promoting agents capable of synthesizing phytohormones, uptaking nutrients, and controlling pathogens. There is a strong potential to exploit them in the agriculture field like biofertilizers and biocontrol agents. In this work, we aimed to evaluate endophytic fungi isolated from Pachystachys lutea for their potential to solubilize phosphate, synthesise indole acetic acid (IAA), antagonize phytopathogens, and promote plant growth under greenhouse conditions. The phosphate solubilization efficiency was assessed on Pikovskaya’s agar medium. For analysis of IAA production, mycelia plugs of endophytes were cultured in Potato Dextrose Broth medium supplemented with L-tryptophan, with Salkowski Reagent, and the absorbance of the culture was measured. The antagonism evaluation of strain Alternaria sp. PL75 against phytopathogens was performed using the paired-culture technique. The promotion of plant growth provided by Alternaria sp. PL75 was evaluated in tomato plants. All strains evaluated were able to solubilize phosphate; however, the strain Alternaria sp. PL75 was the most effective (4.29). Two strains, Nemania sp. PL27 and Alternaria sp. PL75, produced 1.86 and 1.73 & 956;g mL-1 of IAA, respectively. In the antagonism assay, the endophyte Alternaria sp. PL75 and its fungal extract showed the best results against the pathogen Moniliophthora perniciosa. The greenhouse experiment result showed the endophyte Alternaria sp. PL75 increased the plantlets emergency speed index and the percentage of germination from 60 to 81.63%. It was also observed a statistical significance in the shoot length of the treated plants with the endophyte suspension (55.38 cm) compared to the control (41.67 cm).

Genetic diversity and antibacterial activity of endophytic fungi from Zanthoxylum nitidum / 中国中药杂志

In order to reveal the distribution and population characteristics of endophytic fungi from Zanthoxylum nitidum and the antibacterial potential,this study performed molecular identification and analyzed the genetic diversity and antibacterial activity of endophytic fungi from Z. nitidum in Guangxi. Through culture and molecular identification,35 strains,belonging to 15 genera,12 families,10 orders,4 classes,and 2 phyla,were isolated from various tissues of Z. nitidum,of which Colletotrichum and Fusarium were the dominant genera,respectively accounting for 20% of total strains. The diversity of endophytic fungi was significantly different among roots,stems,and leaves,as manifested by the significantly higher Shannon index( H') in stems( 1. 678) than in roots( 0. 882 1) and leaves( 0. 515 4). The antimicrobial activity analysis showed that 14. 28% of endophytic fungi inhibited at least one indicator pathogen. Among them,Fusarium sp. ZN-34 and Fusarium sp. ZN-26 separately demonstrated the strongest inhibitory effect on Escherichia coli and Staphylococcus aureus. In general,Fusarium sp. ZN-26 and Phialemoniopsis plurioloculosa ZN-35 were advantageous in suppressing the two bacteria owing to the broad spectrum and strong efficacy. In summary,Z. nitidum in Guangxi boasts rich endophytic fungi with the majority showing strong antibacterial activity,which can be used as candidates for the extraction and separation of basic antibacterial substances and the development of natural antibacterial agents.

Research strategies for endophytes in medicinal plants based on high-throughput sequencing and traditional culture and isolation methods / 中国中药杂志

The research on endophytes of medicinal plants mainly relies on the traditional culture and isolation methods. Because of their functions such as promoting host growth, improving stress resistance, promoting the accumulation of medicinal active ingredients or directly producing medicinal active ingredients, the endophytes of medicinal plants have gradually attracted wide attention. However, it was found that the strains isolated by traditional methods were not the true dominant endophytes of medicinal plants by comparing the results of traditional culture isolation with high-throughput sequencing. The blind and random nature of traditional methods leads to the lack of standards in terms of medium selection, culture time and interaction between species. On the contrary, high-throughput sequencing technology is an emerging molecular biology technology developed in recent decades. Due to its high resolution level and indepen-dent culture, it can be used for thorough analysis of the community structure and diversity of environmental microorganisms. Therefore, we proposed the strategy of using high-throughput sequencing technology to guide the traditional culture and isolation of endophytes from medicinal plants. Firstly, the endophytic structure and diversity of medicinal plants were completely clear by high-throughput sequencing technology, and the dominant endophytes of the host were unequivocal. Then according to the characteristics of each dominant endophytes design or query suitable medium for its growth to culture and isolation. Finally, the function of the isolates was studied. This method can prevent researchers from missing out on the important functional strains of the host, expand the research scope of endophytes of medicinal plants, and facilitate the in-depth excavation and utilization of endophytes of medicinal plants.

Toxicity of ß-(1→3, 1→6)-á´ -glucans produced by Diaporthe sp. endophytes on Metarhizium anisopliae (Metschnikoff) Sorokin assessed by conidia germination speed parameter / Toxicidade de ß- (1 → 3, 1 → 6) -á´ -glucanas produzidas por endófitos Diaporthe sp. sobre Metarhizium anisopliae (Metschnikoff) Sorokin avaliada pelo parâmetro de velocidade de germinação dos conídios

We have previously reported that ß-(1→3,1→6)-ᴅ-glucans produced by endophytes Diaporthe sp. G27-60 and G65-65 (GenBank accession codes JF766998 and JF767007, respectively) are promising anti-proliferation agents against human breast carcinoma (MCF-7) and hepatocellular carcinoma (HepG2-C3A) cells. However, the literature fails to describe the effects of Diaporthe exopolysaccharides (EPS) on eukaryotic healthy cells. The fungus Metarhiziumanisopliae has been employed as model-system to evaluate the toxicity of pharmaceutical and agricultural-interest substances, taking into account, among other parameters, the speed of conidia germination. Current study verified the effect of different concentrations of Diaporthe ß-glucans on the germination speed of M. anisopliae. Conidia were incubated with ß-glucans treatments (50, 200 and 400 µg/mL) at 28ºC, sampled during 24 h and analyzed by light microscopy. At the end of a 24-h incubation, the amount of germinated conidia reached ≈99% for controls and ranged between 97.7 and 98.6% for treatments. Bayesian analysis indicated that Diaporthe glucans had no toxicity on M. anisopliaeand the curve of germination occurred as expected for this fungal strain. Considering the validity of filamentous fungi as model-systems, results are important data on the toxicity of endophytic EPS on healthy cells and may be associated with our previous results obtained for these polymers against tumor cells.

Anteriormente, um estudo mostrou que ß-(1→3,1→6)-ᴅ-glucanas produzidas pelos endófitos Diaporthe sp. G27-60 e G65-65 (códigos de acesso no GenBank JF766998 e JF767007, respectivamente) são agentes promissores com ação antiproliferativa contra células HepG2-C3A (hepatoma humano) e MCF-7 (adenocarcinoma mamário humano). No entanto, os efeitos de exopolissacarídeos (EPS) produzidos por fungos do gênero Diaporthe em células eucarióticas sadias não estão descritos na literatura atual. O fungo Metarhiziumanisopliae tem sido utilizado como sistema-modelo para avaliar a toxicidade de substâncias de interesse farmacêutico e agronômico, considerando, entre outros parâmetros, a velocidade de germinação de conídios. O presente estudo teve como objetivo verificar os efeitos de diferentes concentrações de ß-glucanas produzidas por Diaporthe sp. sobre a velocidade de germinação de M. anisopliae. Os conídios foram incubados com os tratamentos de ß-glucanas (50, 200 e 400 µg/mL) a 28 ºC, com amostras coletadas ao longo de 24 h, e analisados por microscopia de luz. Ao final das 24 h de incubação, o total de conídios germinados nos controles foi de ≈99%, e variou entre 97,7 e 98,6% para os tratamentos. A análise bayesiana indicou que as glucanas de Diaporthe sp. não apresentaram toxicidade sobre M. anisopliae, e a curva de germinação atendeu ao esperado para essa linhagem fúngica. Considerando a validade dos fungos filamentosos como sistemas-modelo, esses resultados representam dados importantes sobre a toxicidade dos EPS de endófitos sobre células sadias e podem ser associados aos resultados anteriormente obtidos para esses polímeros em testes contra células tumorais.

Actividad antimicrobiana de hongos endófitos de las plantas medicinales Mammea americana (Calophyllaceae) y Moringa oleifera (Moringaceae) / Antimicrobial activity of endophytic fungi from the medicinal plants Mammea americana (Calophyllaceae) and Moringa oleifera (Moringaceae)

Introducción. Las enfermedades infecciosas son una causa importante de muertes en el mundo. La resistencia antimicrobiana es un problema global, por lo que es conveniente la investigación de nuevas fuentes de agentes antimicrobianos de origen natural potencialmente efectivos. Objetivo. Evaluar la actividad antimicrobiana de hongos endófitos de Mammea americanay Moringa oleifera en la cepa sensible (ATCC 29213) y en la cepa resistente (USb003) de Staphylococcusaureus, así como en la cepa sensible (ATCC 25922) y la cepa resistente (USb007) de Escherichia coli. Materiales ymétodos. Se aislaron 14 hongos endófitos de las hojas, semillas y tallos de las dos plantas en estudio. Se evaluó su actividad antimicrobiana mediante la formación de halos de sensibilidad por ensayo dual in vitro y pruebas con extractos etanólicos crudos provenientes de los endófitos a los que se les evaluó la concentración mínima inhibitoria (CMI), la concentración bactericida mínima (CBM) y la citotoxicidad. Resultados. Tres extractos etanólicos de Penicillium sp., Cladosporium sp. (001) y Cladosporium sp.(002) presentaron mayores halos de inhibición en cepas sensibles y resistentes de E. coli y S. aureus. La CMI y la CBM halladas fueron estadísticamente significativas (p≤0,05), comparadas con el control de gentamicina. Las pruebas de citotoxicidad (concentración citotóxica, CC50>1.000) demostraron que los hongos endófitos poseen características bactericidas y no ocasionan daño alguno. Conclusión. Se halló una fuente de metabolitos secundarios activos con propiedades antimicrobianas y no tóxicas en los hongos endófitos de M. oleifera y M. americana;estos hallazgos son importantes para continuar con la identificación química de los compuestos y el estudio de sus mecanismos de acción en estas plantas en las que el aislamiento de endófitos ha sido escaso.

Introduction: Infectious diseases represent one of the leading causes of death worldwide. Considering the growing global challenge of antimicrobial resistance, research into new sources of potentially effective antimicrobial agents from natural origins is of great importance for world health. Objective: To evaluate the antimicrobial activity of endophytic fungi from Mammea americana and Moringa oleifera upon Staphylococcus aureus (ATCC 29213), S. aureus(resistant strain USb003), Escherichia coli (ATCC 25922), and E. coli (resistant strain USb007). Materials and methods: We isolated endophytic fungi from the leaves, seeds, and stems of the two plants under study. We evaluated their antimicrobial activity through the formation of sensitivity haloes in dual tests in vitro, as well as in trials using crude ethanolic extracts from the endophytes. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and cytotoxicity o the substances were analyzed. Results: Three ethanolic extracts of Penicillium sp., Cladosporium (001), and Cladosporium (002) exhibited the greatest inhibition halos in sensitive and resistant strains of E. coli and S. aureus. The MIC and CBM found were statistically significant (p≤0.05) compared with the gentamicin control. Furthermore, the cytotoxicity test results of CC50>1,000 demonstrated that the endophytic fungi studied exhibit bactericidal characteristics without causing unintended damage. Conclusion: The endophytic fungi M. oleifera and M. americana represent a source of active secondary metabolites with antimicrobial and non-toxic properties. In light of these findings, further research should proceed with chemical identification of the compounds and the study of their mechanisms of action, especially given the paucity of current scientific knowledge concerning the isolation of endophytes in these plants.

Tolerance of dark septate endophytic fungi (DSE) to 1 agrochemicals in vitro / Tolerancia de hongos endofíticos septados oscuros a agroquímicos in vitro

Abstract Dark septate endophytes (DSE) are a heterogeneous group of fungi, mostly belonging to the Phylum Ascomycota, that are involved in a mutualistic symbiosis with plant roots. The aim of this study is to evaluate the behavior of two strains of DSE isolated from wheat roots of two cropping areas in the province of Buenos Aires, Argentina, against some agrochemicals. Of all the isolates obtained, two strains were identified as Alternaria alternata and Cochliobolus sp. These DSE were found to be tolerant to glyphosate, carbendazim and cypermethrin when evaluated at the recommended agronomic dose (AD), 2 AD and, in some cases, 10 AD. This work contributes to the study of the biology of this group of fungi and their tolerance in the presence of xenobiotics widely used in agriculture.© 2019 Asociaci´on Argentina de Microbiolog´ıa. Published by Elsevier Espa˜na, S.L.U. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/bync-nd/4.0/).

Resumen Los endófitos septados oscuros (DSE) son un grupo heterogéneo de hongos que participan de una simbiosis mutualista con raíces de plantas, perteneciendo principalmente al Phylum Ascomycota. El objetivo de este estudio fue aislar DSE de raíces de trigo proveniente de dos áreas de cultivo de la provincia de Buenos Aires y evaluar el comportamiento de dos cepas de DSE aisladas de raíces de trigo frente a algunos agroquímicos en dos áreas de cultivo de la provincia de Buenos Aires. De todos los aislamientos obtenidos se seleccionaron dos cepas que se identificaron como Alternaria alternata y Cochliobolus sp. Se encontró que estos DSE son tolerantes al glifosato, el carbendazim y la cipermetrina, evaluados a las dosis agronómicas recomendadas (AD), a 2x AD y, en algunos casos, a 10x AD. Este trabajo contribuye al conocimiento de la biología de este grupo de hongos y su tolerancia a xenobióticos ampliamente utilizados en la agricultura.

Adaptation of plants to high-calcium content kart regions: possible involvement of symbiotic microorganisms and underlying mechanisms / Adaptação de plantas a regiões de kart com alto teor de cálcio: possível envolvimento de microrganismos simbióticos e mecanismos subjacentes

Abstract Rhizosphere microorganisms and endophytes can help their hosts absorb nutrients and regulate the levels of plant hormones. Moreover, they can modulate the expressions of host genes, assist hosts in eliminating reactive oxygen species (ROS) and secreting volatile organic compounds. Therefore, rhizosphere microorganisms and endophytes are considered as determinant factors driving processes involved in the growth of host plants. However, the physiological and ecological functions, as well as the molecular mechanism underlying the behavior of rhizosphere microorganisms and endophytes in their role in the adaptive capacity of host plants in the karstic high-calcium environment have not been systematically studied. This review summarizes the physiological and molecular mechanisms of rhizosphere microorganisms and endophytes which help host plants to adapt to various kinds of adverse environments. The adaptive capacities of plants growing in adverse environments, partly, or totally, depends on microorganisms co-existing with the host plants.

Resumo Os microorganismos e endófitos da rizosfera podem ajudar seus hospedeiros a absorver nutrientes e regular os níveis de hormônios vegetais. Além disso, eles podem modular as expressões dos genes hospedeiros, auxiliar os hospedeiros na eliminação de espécies reativas de oxigênio (ROS) e secretar compostos orgânicos voláteis. Portanto, microorganismos e endófitos da rizosfera são considerados determinantes dos processos envolvidos no crescimento de plantas hospedeiras. No entanto, as funções fisiológicas e ecológicas, bem como o mecanismo molecular subjacente ao comportamento dos microrganismos e endofíticos da rizosfera no seu papel na capacidade adaptativa das plantas hospedeiras no ambiente cárstico de alto teor de cálcio, não foram sistematicamente estudados. Esta revisão resume os mecanismos fisiológicos e moleculares de microrganismos e endófitos da rizosfera que ajudam as plantas hospedeiras a se adaptarem a vários tipos de ambientes adversos. As capacidades adaptativas das plantas que crescem em ambientes adversos, em parte ou totalmente, dependem de microrganismos coexistentes com as plantas hospedeiras.

CO2 Fertilizer Effect on Growth, Polyphenols, and Endophytes in Two Baccharis Species

Abstract In a climate change context, the buildup of CO2 will affect plant communities worldwide. This study evaluated the effects of CO2 enrichment on the development and defense of two Cerrado native species Baccharis dracunculifolia and B. platypoda and their associated endophytic fungi richness. The study took place in Open-Top Chambers, two with ambient CO2 concentration (~400 ppm) and two in an enriched environment (~800 ppm). Baccharis platypoda developed 20% more leaves under enriched CO2 conditions, whereas B. dracunculifolia was 30% taller and showed 27% more leaves than those under ambient conditions. In both species, leaf polyphenol concentration did not differ between treatments. Nevertheless, polyphenol content had a positive correlation with plant height on both species' individuals grown under CO2 enriched conditions. Endophytic fungi richness and colonization rate on both plant species did not differ between ambient and enriched conditions. Our results show the positive effect of CO2 fertilizer in at least one of the measured growth parameters. An important new finding was a synergistic increase in growth and chemical defense in both studied species under enriched CO2 conditions, suggesting higher carbon assimilation and accumulation. This study suggests that the effects on primary productivity and secondary metabolites of Baccharis species will potentially reflect on the diversity and distribution of Cerrado plants and their associated animal communities.

Enzyme Production by Induratia spp. Isolated from Coffee Plants in Brazil

Abstract Endophytic fungi belonging to the genus Muscodor now transferred to Induratia are known producers of bioactive volatile organic compounds (VOCs) with many industrial applications. However, the members of this genus have rarely been reported to produce non-volatile metabolites including enzyme. Enzymes of the endophytes are degraders of the polysaccharides available in the host plants and the knowledge of enzyme production by Induratia spp. may provide insights into their possible biotechnological applications. The aim of this study was to evaluate the activity of amylase, cellulase, lipase, pectinase, phytase, protease, endo β-1,4 glucanase and exo β-1,4 glucanase enzymes produced by fungi of the species Induratia coffeana, Induratia yucatanensis and Induratia sp. isolated from organic coffee plants. All Induratia spp. were able to produce the extracellular enzymes cellulase, pectinase, protease, and phytase. Eight fungi were able to produce lipase and four produced amylase. The specific activity of endo β-1, 4 glucanase and exo β-1,4 glucanase enzymes were detected for 9 and 8 endophytic fungi, respectively. This work demonstrated for the first time, the array of enzymes produced by Induratia spp. isolated from Coffea arabica in organic systems in Brazil.

Screening of endophytic fungi against southern blight disease pathogen-Sclerotium delphinii in Dendrobium catenatum / 中国中药杂志

In order to screen the endophytic fungi that can enhance the host(Dendrobium catenatum) resistance to Sclerotium delphinii, the antagonism between each of the 43 endophytic fungi and the pathogen S. delphinii were tested. The results showed that 6 endophytic fungi(DCR2, DCR5, DCR21, DCR22, DCR42, DCR43) have strong activities against the pathogen, the inhibition rates were 49.2%, 49.2%, 47.2%, 56.2%, 53.2%, 48.0%, respectively. Then D. catenatum plantlets were inoculated with both S. delphinii and each of these six endophytic fungi. As a result, the incidence rates of leaves and stems of the D. catenatum plantlets inoculated with DCR2 and the pathogen were both significantly lower than those with other treatments, and the plantlet death rate was 0. It showed that DCR2 Trichoderma polysporum could effectively inhibit the southern blight disease of D. catenatum. Through the endophytic fungal re-isolation test, it was found that DCR2 can colonize in the roots, stems, and leaves of D. catenatum. The research will provide new ideas for the prevention and treatment of the southern blight disease of D. catenatum. It is also significant for reducing pesticide use, ensuring food safety, and promoting the sustainable development of D. catenatum industry. Furthermore, it will provide a basis for the disease control in other crops.

HMG-CoA Reductase Inhibitory Activity of Leaf-associated Fungi

@#Background. Cholesterol is an important biomolecule for cells. However, because of certain lifestyle, the amount of cholesterol can increase beyond what our bodies can consume. Increased intake may result in the accumulation of cholesterol in the blood leading to atherosclerosis that can lead to congestive heart failure. With the use of statins, cholesterol levels are reduced therefore lowering the risk for this disease. It does so by inhibiting the hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase, the first committed enzyme in cholesterol biosynthesis. In light of the increasing cases of hypercholesterolemia, there is a need to discover novel classes of HMG-CoA inhibitors. Objective. The primary objective of this study was to screen extracts of leaf-associated fungi for their capacity to inhibit hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase, the first committed enzyme in cholesterol biosynthesis. Methods. Eight (8) plants were sampled for the fungal epiphytes and endophytes on their leaves. The fungal isolates were identified by sequencing the internal transcribed region (ITS) of the 18S rDNA. All fungal isolates were cultured in 20 flasks containing 300 mL potato dextrose broth at 30°C for 14 days. The culture broths were then subjected to reduction in volume using a rotary evaporator. HMG-CoA reductase inhibition assay was carried out using the ethyl acetate extracts from the culture broths. Reagent grade pravastatin was used as the positive control. Results. There were a total of sixty-six (66) fungal taxa that were tested for their capacity to inhibit the enzyme HMG-CoA reductase. Of the 50 that tested positive, there were 25 families represented and 5 isolates were of uncertain status taxonomically (incertae sedis). There were also nine classes that were represented and the class with the most number of isolates was Sordariomycetes. The highest percentage inhibition was observed in Pestalotiopsis lespedezae with 65.01 % inhibition. The other fungi with notable inhibitory activities were Colletotrichum cymbidiicola (64.16%) and Schizophyllum commune (57.85%). Conclusions. This study may be the first report of production of HMG-CoA reductase inhibitors in the genus Colletotrichum and in the other leaf-associated fungal taxa that tested positive for HMG-CoA reductase inhibition. It is therefore very promising that a novel statin compound, or even a new class of substances with antihypercholesterolemic bioactivity may be discovered from these leaf-associated fungal isolates. The crude extracts of these fungi are prime candidates for downstream fractionation for the subsequent isolation and structure elucidation of the bioactive compound.

Endoglucanase production by endophytic fungi isolated from vitis labrusca l. with peanut hull and sawdust as substrates / Produção de endoglucanase por fungos endofíticos isolados de Vitis labrusca L. utilizando casca de amendoim e serragem como substratos

Endoglucanases are enzymes widely employed in different industrial fields, albeit with high production costs. Studies on new microbial sources and low-cost substrates are highly relevant, including those on agro-industrial. Current analysis evaluates peanut hull (PH) and sawdust (SD) as substrates for submerged cultures of 14 endophytic fungi isolated from grapevine (Vitis labrusca L.) cultivars Bordô and Concord. Endophytes were grown on a carboxymethylcellulose (CMC) medium and the cup plate assay showed that eight strains (belonging to genera Cochliobolus, Diaporthe, Fusarium and Phoma) had positive results: enzymatic halos ranged from 10.8±0.02to 15.5±0.07 mm in diameter. Diaporthe sp. strains (GenBank accession codes KM362392, KM362368 and KM362378) and Fusariumculmorum KM362384 were highlighted as the most promising sources. Further, PH and SD as substrates for the fermentation of these fungi were evaluated by the cup plate assay and endoglucanase activity assay. Highest halo diameters were obtained for Diaporthe sp. KM362392: 16.1±0.01 mm (CMC), 14.5±0.01 mm (PH) and 14.7±0.03 mm (SD). The fungus also presented the highest levels of endoglucanase activity: analysis of variance revealed that CMC (3.52±0.98 µmol/min), PH (2.93±0.23 µmol/min) and SD (3.26±0.38 µmol/min) were similarly efficient as substrates. Results deepen knowledge on V. labrusca endophytes that may be endoglucanase sources, eventhough further optimizations in submerged cultures with PH and SD should be undertaken to increase theenzymatic production from these wastes.

Endoglucanases são enzimas amplamente empregadas em diferentes setores industriais; embora sua produção apresente custos elevados. Estudos sobre novas fontes microbianas e substratos mais baratos são de grande importância, incluindo os resíduos agroindustriais. Nesse estudo, casca de amendoim (CA) e serragem (SE) foram testadas como substratos para o cultivo submerso de 14 fungos endofíticos isolados das cultivares Bordô e Concord de videira (Vitis labrusca L.) Os endófitos foram crescidos em meio contendo carboximetilcelulose (CMC) e o ensaio cup plate mostrou resultados positivos para oito fungos (pertencentes aos gêneros Cochliobolus, Diaporthe, Fusarium and Phoma); os halos enzimáticos variaram entre 10,8±0,02 e 15,5±0,07 mm de diâmetro. Linhagens de Diaporthe sp. (códigos de acesso no GenBank KM362392, KM362368 e KM362378) e Fusariumculmorum KM362384 se destacaram como produtores mais promissores. Então, o uso de CA e SE como substratos para a fermentação desses fungos foi avaliado pelo ensaio cup plate e pela quantificação da atividade de endoglucanase. Os maiores halos enzimáticos foram obtidos para Diaporthe sp. KM362392: 16,1±0,01 mm (CMC), 14,5±0,01 mm (CA) e 14,7±0,03 mm (SE). Esse fungo também apresentou os maiores níveis de endoglucanase: a análise de variância revelou que CMC (3,52±0,98 µmol/min), CA (2,93±0,23 µmol/min) e SE (3,26±0,38 µmol/min) foram substratos similarmente eficientes. Esses resultados expandem o conhecimento sobre endófitos de V. labrusca que são fontes de endoglucanases; futuras otimizações quanto ao cultivo submerso com CA e SE podem ser utilizadas para aumentar a produção enzimática a partir do uso desses resíduos.

Produção de enzimas por fungos filamentosos / Production of enzymes by filamental fungi

Estudos utilizando fungos endofíticos como produtores de metabólitos secundários de interesse biotecnológico vem sendo explorados. Assim, o presente trabalho objetivou avaliar a produção de enzimas por fungos filamentosos endofíticos, sendo escolhida a cepa 50 (C50), proveniente da coleção de cultura do Laboratório de Produtos Naturais e Biotecnologia (LPNBio) da UESB. A produção das enzimas amilase, celulase, invertase, lipase e poligalacturonase foi avaliada pelo o índice enzimático, atividade enzimática e verificado o tempo de fermentação de maior produtividade. Com exceção da invertase, a C50 apresentou atividade para as demais enzimas, destaque para lipase e poligalacturonase no tempo de 96 horas de fermentação. Estes resultados mostraram que a C50 tem potencial para ser explorada como produtora de enzimas.

Isolation and identification of endophytic fungi from Huperzia serrata and their metabolites' inhibitory activities against acetylcholinesterase and anti-inflammatory activities / 中国中药杂志

A total of 27 endophytic fungal strains were isolated from Huperzia serrata,which were richly distributed in the stems and leaves while less distributed in roots. The 27 strains were identified by Internal Transcribed Spacer( ITS) r DNA molecular method and one of the strains belongs to Basidiomycota phylum,and other 26 stains belong to 26 species,9 general,6 families,5 orders,3 classes of Ascomycota Phylum. The dominant strains were Colletotrichum genus,belonging to Glomerellaceae family,Glomerellales order,Sordariomycetes class,Ascomycota Phylum,with the percentage of 48. 15%. The inhibitory activities of the crude extracts of 27 endophytic fungal strains against acetylcholinesterase( ACh E) and nitric oxide( NO) production were evaluated by Ellman's method and Griess method,respectively. Crude extracts of four fungi exhibited inhibitory activities against ACh E with an IC50 value of 42. 5-62. 4 mg·L~(-1),and some fungi's crude extracts were found to inhibit nitric oxide( NO) production in lipopolysaccharide( LPS)-activated RAW264. 7 macrophage cells with an IC50 value of 2. 2-51. 3 mg·L~(-1),which indicated that these fungi had potential anti-inflammatory activities.The chemical composition of the Et OAc extract of endophytic fungus HS21 was also analyzed by LCMS-IT-TOF. Seventeen compounds including six polyketides,four diphenyl ether derivatives and seven meroterpenoids were putatively identified.