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1.
Fungal Genet Biol ; 173: 103899, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38802054

RESUMO

Fusarium head blight is a devastating disease that causes severe yield loses and mycotoxin contamination in wheat grain. Additionally, balancing the trade-off between wheat production and disease resistance has proved challenging. This study aimed to expand the genetic tools of the endophyte Phomopsis liquidambaris against Fusarium graminearum. Specifically, we engineered a UDP-glucosyltransferase-expressing P. liquidambaris strain (PL-UGT) using ADE1 as a selection marker and obtained a deletion mutant using an inducible promoter that drives Cas9 expression. Our PL-UGT strain converted deoxynivalenol (DON) into DON-3-G in vitro at a rate of 71.4 % after 36 h. DON inactivation can be used to confer tolerance in planta. Wheat seedlings inoculated with endophytic strain PL-UGT showed improved growth compared with those inoculated with wildtype P. liquidambaris. Strain PL-UGT inhibited the growth of Fusarium graminearum and reduced infection rate to 15.7 %. Consistent with this finding, DON levels in wheat grains decreased from 14.25 to 0.56 µg/g when the flowers were pre-inoculated with PL-UGT and then infected with F. graminearum. The expression of UGT in P. liquidambaris was nontoxic and did not inhibit plant growth. Endophytes do not enter the seeds nor induce plant disease, thereby representing a novel approach to fungal disease control.


Assuntos
Ascomicetos , Endófitos , Fusarium , Glucosiltransferases , Doenças das Plantas , Tricotecenos , Triticum , Triticum/microbiologia , Triticum/genética , Tricotecenos/metabolismo , Fusarium/genética , Fusarium/efeitos dos fármacos , Fusarium/enzimologia , Endófitos/genética , Endófitos/enzimologia , Endófitos/metabolismo , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Glucosiltransferases/genética , Glucosiltransferases/metabolismo , Ascomicetos/genética , Ascomicetos/efeitos dos fármacos , Ascomicetos/enzimologia , Resistência à Doença/genética , Micotoxinas/metabolismo
2.
J Exp Bot ; 75(10): 3153-3170, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38394357

RESUMO

Endophytic symbioses between plants and fungi are a dominant feature of many terrestrial ecosystems, yet little is known about the signaling that defines these symbiotic associations. Hydrogen peroxide (H2O2) is recognized as a key signal mediating the plant adaptive response to both biotic and abiotic stresses. However, the role of H2O2 in plant-fungal symbiosis remains elusive. Using a combination of physiological analysis, plant and fungal deletion mutants, and comparative transcriptomics, we reported that various environmental conditions differentially affect the interaction between Arabidopsis and the root endophyte Phomopsis liquidambaris, and link this process to alterations in H2O2 levels and H2O2 fluxes across root tips. We found that enhanced H2O2 efflux leading to a moderate increase in H2O2 levels at the plant-fungal interface is required for maintaining plant-fungal symbiosis. Disturbance of plant H2O2 homeostasis compromises the symbiotic ability of plant roots. Moreover, the fungus-regulated H2O2 dynamics modulate the rhizosphere microbiome by selectively enriching for the phylum Cyanobacteria, with strong antioxidant defenses. Our results demonstrated that the regulation of H2O2 dynamics at the plant-fungal interface affects the symbiotic outcome in response to external conditions and highlight the importance of the root endophyte in reshaping the rhizosphere microbiota.


Assuntos
Arabidopsis , Endófitos , Homeostase , Peróxido de Hidrogênio , Microbiota , Raízes de Plantas , Rizosfera , Simbiose , Arabidopsis/microbiologia , Arabidopsis/fisiologia , Endófitos/fisiologia , Peróxido de Hidrogênio/metabolismo , Raízes de Plantas/microbiologia , Raízes de Plantas/fisiologia , Ascomicetos/fisiologia
3.
J Appl Microbiol ; 135(4)2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38520150

RESUMO

AIMS: In this study, the control effects of synthetic microbial communities composed of peanut seed bacteria against seed aflatoxin contamination caused by Aspergillus flavus and root rot by Fusarium oxysporum were evaluated. METHODS AND RESULTS: Potentially conserved microbial synthetic communities (C), growth-promoting synthetic communities (S), and combined synthetic communities (CS) of peanut seeds were constructed after 16S rRNA Illumina sequencing, strain isolation, and measurement of plant growth promotion indicators. Three synthetic communities showed resistance to root rot and CS had the best effect after inoculating into peanut seedlings. This was achieved by increased defense enzyme activity and activated salicylic acid (SA)-related, systematically induced resistance in peanuts. In addition, CS also inhibited the reproduction of A. flavus on peanut seeds and the production of aflatoxin. These effects are related to bacterial degradation of toxins and destruction of mycelia. CONCLUSIONS: Inoculation with a synthetic community composed of seed bacteria can help host peanuts resist the invasion of seeds by A. flavus and seedlings by F. oxysporum and promote the growth of peanut seedlings.


Assuntos
Aflatoxinas , Sementes , RNA Ribossômico 16S/genética , Sementes/microbiologia , Fungos/genética , Plântula/microbiologia , Bactérias/genética , Arachis/microbiologia
4.
Plant Mol Biol ; 109(6): 703-715, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35522401

RESUMO

Fungal endophytes establish symbiotic relationships with host plants, which results in a mutual growth benefit. However, little is known about the plant genetic response underpinning endophyte colonization. Phomopsis liquidambaris usually lives as an endophyte in a wide range of asymptomatic hosts and promotes biotic and abiotic stress resistance. In this study, we show that under low nitrogen conditions P. liquidambaris promotes rice growth in a hydroponic system, which is free of other microorganisms. In order to gain insights into the mechanisms of plant colonization by P. liquidambaris under low nitrogen conditions, we compared root and shoot transcriptome profiles of root-inoculated rice at different colonization stages. We determined that genes related to plant growth promotion, such as gibberellin and auxin related genes, were up-regulated at all developmental stages both locally and systemically. The largest group of up-regulated genes (in both roots and shoots) were related to flavonoid biosynthesis, which is involved in plant growth as well as antimicrobial compounds. Furthermore, genes encoding plant defense-related endopeptidase inhibitors were strongly up-regulated at the early stage of colonization. Together, these results provide new insights into the molecular mechanisms of plant-microbe mutualism and the promotion of plant growth by a fungal endophyte under nitrogen-deficient conditions.


Assuntos
Endófitos , Oryza , Ascomicetos , Endófitos/fisiologia , Nitrogênio , Raízes de Plantas/genética
5.
Fungal Genet Biol ; 158: 103650, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34923123

RESUMO

Fusarium head blight (FHB) is a disease that affects wheat crops worldwide and is caused by Fusarium graminearum. Effective and safe strategies for the prevention and treatment of the disease are very limited. Phomopsis liquidambaris, a universal endophyte, can colonize wheat. Two engineered strains, Phomopsis liquidambaris OE-Chi and IN-Chi, were constructed by transformation with a plasmid and integration of a chitinase into the genome, respectively. The OE-Chi and IN-Chi strains could inhibit the expansion of Fusarium sp. in plate confrontation assays in vitro. Colonization of the OE-Chi strain in wheat showed better effects than colonization of the IN-Chi strain and alleviated the inhibition of wheat growth caused by F. graminearum. The shoot length, root length and fresh weight of infected wheat increased by 164.9%, 115.4%, and 190.7%, respectively, when the plants were inoculated with the OE-Chi strain. The peroxidase (POD) activity in the wheat root increased by 38.0%, and it was maintained at a high level in the shoot, which suggested that the OE-Chi strain could enhance the resistance of wheat to F. graminearum. The root and shoot superoxide dismutase (SOD) activities were decreased by 11.8% and 19.0%, respectively, which may be helpful for colonization by the OE-Chi strain. These results suggested that the Phomopsis liquidambaris OE-Chi strain may be a potential endophyte in the biocontrol of FHB.


Assuntos
Quitinases , Fusarium , Ascomicetos , Quitinases/genética , Endófitos/genética , Fusarium/genética , Doenças das Plantas , Triticum
6.
New Phytol ; 235(3): 1212-1230, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35488499

RESUMO

The simultaneous symbiosis of leguminous plants with two root mutualists, endophytic fungi and rhizobia is common in nature, yet how two mutualists interact and co-exist before infecting plants and the concomitant effects on nodulation are less understood. Using a combination of metabolic analysis, fungal deletion mutants and comparative transcriptomics, we demonstrated that Bradyrhizobium and a facultatively biotrophic fungus, Phomopsis liquidambaris, interacted to stimulate fungal flavonoid production, and thereby primed Bradyrhizobial nodulation signaling, enhancing Bradyrhizobial responses to root exudates and leading to early nodulation of peanut (Arachis hypogaea), and such effects were compromised when disturbing fungal flavonoid biosynthesis. Stress sensitivity assays and reactive oxygen species (ROS) determination revealed that flavonoid production acted as a strategy to alleviate hyphal oxidative stress during P. liquidambaris-Bradyrhizobial interactions. By investigating the interactions between P. liquidambaris and a collection of 38 rhizobacteria, from distinct bacterial genera, we additionally showed that the flavonoid-ROS module contributed to the maintenance of fungal and bacterial co-existence, and fungal niche colonization under soil conditions. Our results demonstrate for the first time that rhizobial nodulation signaling can be primed by fungi before symbiosis with host plants and highlight the importance of flavonoid in tripartite interactions between legumes, beneficial fungi and rhizobia.


Assuntos
Bradyrhizobium , Fabaceae , Rhizobium , Arachis , Bradyrhizobium/fisiologia , Fabaceae/microbiologia , Flavonoides/metabolismo , Nodulação , Espécies Reativas de Oxigênio/metabolismo , Simbiose
7.
Plant Cell Environ ; 45(6): 1813-1828, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35274310

RESUMO

In the soil, plant roots associated with fungi often encounter uneven distribution of nitrate (NO3- )/ammonium (NH4+ ) patches, but the mechanism underlying N form-influenced plant-fungal interactions remains limited. We inoculated Arabidopsis with a root endophyte Phomopsis liquidambaris, and evaluated the effects of P. liquidambaris on plant performance under NO3- or NH4+ nutrition. Under NO3- nutrition, P. liquidambaris inoculation promoted seedling growth, whereas under NH4+ nutrition, P. liquidambaris suppressed seedling growth. Under high NH4+ conditions, fungus-colonized roots displayed increased NH4+ accumulation and NH4+ efflux, similar to the effect of ammonium stress caused by elevated NH4+ levels. Notably, this fungus excluded NH4+ during interactions with host roots, thereby leading to increased NH4+ levels at the plant-fungal interface under high NH4+ conditions. A nitrite reductase-deficient strain that excludes NO3- but absorbs NH4+ , decreased NH4+ levels in Arabidopsis shoots and rescued plant growth and nitrogen metabolism under high NH4+ levels. Transcriptomic analysis highlighted that P. liquidambaris had altered transcriptional responses associated with plant response to inorganic N forms. Our results demonstrate that fungus-regulated NO3- /NH4+ dynamics at the plant-fungal interface alters plant response to NO3- /NH4+ nutrition. This study highlights the essential functions of root endophytes in plant adaptation to soil nitrogen nutrients.


Assuntos
Compostos de Amônio , Arabidopsis , Compostos de Amônio/metabolismo , Arabidopsis/metabolismo , Endófitos/metabolismo , Fungos , Nitratos/metabolismo , Nitrogênio/metabolismo , Raízes de Plantas/metabolismo , Solo
8.
J Appl Microbiol ; 133(3): 1566-1580, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35686661

RESUMO

AIMS: This study evaluated the control effect of the endophytic fungus Phomopsis liquidambaris B3 against rice bakanae disease (RBD) caused by Fusarium proliferatum and the disease control result of different inoculation times of beneficial micro-organisms. METHODS AND RESULTS: Rice seedlings preinoculated, coinoculated and noninoculated with B3 were exposed to F. proliferatum stress and grown under controlled conditions. Greenhouse experimental results showed that rice preinoculation with B3 significantly reduced rice bakanae disease by 21.45%, inhibited the colonization of F. proliferatum, increased defence-related enzyme activities, upregulated the expression of defence genes and promoted plant photosynthesis. However, bakanae disease in rice coinoculation with B3 increased by 11.45%, resulted in excessive reactive oxygen species (ROS) bursts and plant cell death. CONCLUSIONS: Preinoculation with the endophytic fungus P. liquidambaris B3 significantly reduced rice bakanae disease by triggering the SA-dependent defence pathways of plants, and promoted plant growth. However, coinoculatiton with P. liquidambaris B3 activated excessive defence responses, resulting in plants cell death and aggravation of bakanae disease. SIGNIFICANCE AND IMPACT OF THE STUDY: This study indicated that P. liquidambaris B3 was an effective method for agricultural control against rice bakanae disease caused by F. proliferatum, and provides an experimental basis for the development of sustainable endophytic fungal resources to effectively control plant diseases caused by pathogenic fungi, and suggests that precise application of beneficial micro-organisms may be become a key factor in farmland crop disease management.


Assuntos
Ascomicetos , Fusarium , Micoses , Oryza , Ascomicetos/genética , Fusarium/metabolismo , Oryza/microbiologia
9.
Curr Microbiol ; 79(6): 172, 2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35476161

RESUMO

Rice-wheat rotation is one of the most intensive agricultural planting modes in China and is pivotal to develop optimized straw-returning management in situ to improve soil fertility and productivity in agricultural ecosystems. Previous studies have mainly focused on the effects of straw return with a single application of organic fertilizers. The integrated management of different fertilizers in improving the management of straw return in situ is not well known. In this study, a field experiment was conducted from 2017 to 2019 to explore the effects of a combined system of modified organic substrate (MOS) and straw-degrading compound microbial agent (CMA) on soil physiochemical properties, labile organic carbon, microbial activities, and soil microbial community composition under the background of direct crop straw return and chemical fertilizer utilization. Four treatments were designed: (1) control check; (2) CMA; (3) MOS; and (4) MOS + CMA. The results showed that the MOS + CMA treatment had the combined advantages of soil organic matter (SOM) accumulation, soil nutrient increase and soil microbial community alteration, which may be more suitable for improving the quality and fertility of sandy loam soil. This study provides novel insights for further understanding the effects of organic substrates and composite microbial agents on SOM changes and microbial community composition and function in the field, which has important implications for sustainable crop production and agricultural development.


Assuntos
Microbiota , Oryza , Fertilizantes , Solo/química , Triticum
10.
Ecotoxicol Environ Saf ; 235: 113415, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35306213

RESUMO

Phenanthrene cannot be effectively degraded in the agricultural production systems and it is greatly hazardous for food safety and human health. In our study, the remediation ability and mechanism of rice and endophytic fungus Phomopsis liquidambaris interaction on phenanthrene in the rice-growing environment were explored using laboratory and pot experiments. The results showed that plant-endophyte interaction had the potential to enhance remediation on phenanthrene contamination in the rice-growing environment. The content of phenanthrene in soil and rice (including leaves, roots, and grains) of the plant-endophyte interaction system was about 42% and 27% lower than of the non-inoculated treatment under 100 mg kg-1 treatment. The mechanism may be related to the improvement of plant growth, root activity, chlorophyll content, ATP energy supply, and antagonistic ability of rice to promote the absorption of phenanthrene in the rice-growing environment, and then the phenanthrene absorbed into the rice was degraded by improving the phenanthrene degrading enzyme activities and gene relative expression levels of P. liquidambaris during plant-endophyte interaction. Moreover, the plant-endophyte interaction system could also promote rice growth and increase rice yield by over 20% more than the control under 50 mg kg-1 treatment. This study indicated a promising potential of the plant-endophyte interaction system for pollution remediation in agriculture.


Assuntos
Oryza , Fenantrenos , Endófitos/metabolismo , Humanos , Oryza/metabolismo , Fenantrenos/metabolismo , Fenantrenos/toxicidade , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Solo
11.
Arch Microbiol ; 203(10): 6215-6229, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34609529

RESUMO

The endophytic fungus Phomopsis liquidambaris is characterized as a plant growth-promoting agent under salt stress, but its mechanism is unknown. Herein, 1-aminocyclopropane-1-carboxylate deaminase (ACCD) from the strain was confirmed that it had the ability of utilizing 1-aminocyclopropane-1-carboxylate as the sole nitrogen source. The full-length ACCD gene was 1152 bp, which encodes a mature protein of 384 amino acids with a molecular mass of 41.53 kDa. The ACCD activity was 3.9-fold in 3 mmol L-1 ACC by qRT-PCR under salt stress comparing with no salt tress. Ethylene production was increased to 34.55-70.60% and reduced the growth of rice by 23-69.73% under salt stress. Inoculation of P. liquidambaris increased root-shoot length, fresh and dry weight, and overall growth of stressed rice seedlings. ACC accumulation, ACC synthase and ACC oxidase activities increased in salt-treated rice seedlings, while they were significantly reduced when P. liquidambaris was inoculated into rice by qRT-PCR. It therefore can be concluded that P. liquidambaris can be used as a plant growth promoting fungus against salt stress and other biotic or abiotic stresses.


Assuntos
Oryza , Carbono-Carbono Liases , Etilenos , Phomopsis , Estresse Salino
12.
Microb Ecol ; 82(1): 49-61, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32656607

RESUMO

Endophytic fungi can profoundly affect host productivity, but the underlying mechanisms of these effects are only partly understood. As the most important regulators of plant-soil feedback, root exudates can easily cause soil sickness in continuous monoculture systems by reducing certain microbes in the rhizosphere. In this study, exudates from roots colonized by the endophytic fungus Phomopsis liquidambaris significantly increased rhizosphere bacterial abundance, soil respiration, microbial biomass and enzyme activities in a long-term continuously cropped peanut soil. Further analysis revealed that P. liquidambaris-colonized root exudates clearly altered the carbon metabolism and rhizosphere bacterial diversity, which were closely correlated with changes in soil chemical properties caused by the exudates from the colonized roots. Finally, a synthetic root exudate experiment further confirmed that the root exudates derived from P. liquidambaris colonization can indeed play an important role in promoting peanut growth. Therefore, these results show that this endophytic fungus could improve the carbon metabolism and rhizosphere bacterial community in long-term monoculture soils via exudates from colonized roots, which contribute to the alleviation of soil sickness.


Assuntos
Rizosfera , Solo , Arachis , Carbono , Fungos , Raízes de Plantas , Microbiologia do Solo
13.
Biotechnol Lett ; 43(1): 119-132, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33128663

RESUMO

Flavonoids, which are mainly extracted from plants, are important antioxidants and play an important role in human diseases. However, the growing market demand is limited by low productivity and complex production processes. Herein, the flavonoids biosynthesis pathway of the endophytic fungus Phomopsis liquidambaris was revealed. The mitogen-activated protein kinase kinase (MAPKK) of the strain was disrupted using a newly constructed CRISPR-Cas9 system mediated by two gRNAs which was conducive to cause plasmid loss. The disruption of the MAPKK gene triggered the biosynthesis of flavonoids against stress and resulted in the precipitation of flavonoids from fermentation broth. Naringenin, kaempferol and quercetin were detected in fed-batch fermentation with yields of 5.65 mg/L, 1.96 mg/L and 2.37 mg/L from P. liquidambaris for dry cell weigh using the mixture of glucose and xylose and corn steep powder as carbon source and nitrogen source for 72 h, respectively. The biosynthesis of flavonoids was triggered by disruption of MAPKK gene in P. liquidambaris and the mutant could utilize xylose.


Assuntos
Flavonoides/biossíntese , Proteínas Fúngicas/genética , Quinases de Proteína Quinase Ativadas por Mitógeno/genética , Phomopsis , Técnicas de Cultura Celular por Lotes , Sistemas CRISPR-Cas , Meios de Cultura/química , Meios de Cultura/metabolismo , Fermentação , Flavonoides/análise , Flavonoides/genética , Proteínas Fúngicas/metabolismo , Edição de Genes , Glucose/metabolismo , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Phomopsis/genética , Phomopsis/metabolismo , Xilose/metabolismo
14.
J Sci Food Agric ; 101(10): 4059-4075, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-33349945

RESUMO

BACKGROUND: Rice spikelet rot disease (RSRD) is an emerging disease that significantly reduces rice yield and quality. In this study, we evaluated the potential use of the broad-spectrum endophytic fungus Phomopsis liquidambaris B3 as a biocontrol agent against RSRD. We also compared the control effects of different treatments, including chemical fungicides and treatment with multiple strains and single strains in combination or individually, against RSRD. The objective of this study was to find an effective and environmentally friendly control strategy to reduce the occurrence of RSRD and improve the rice yield. RESULTS: In pot experiments, the effect of B3 alone was better than that of fungicide or combined measures. The results showed that root colonization by B3 significantly reduced the incidence and disease index of RSRD by 41.0% and 53.8%, respectively. This was related to enhanced superoxide dismutase (SOD), peroxidase (POD), and polyphenol oxidase (PPO) activity, and to significantly upregulated expression levels of OsAOX, OsLOX, OsPAL, and OsPR10 in rice. Moreover, B3 improved the diversity of the bacterial community rather than the fungal community in the rice rhizosphere. It also led to a decrease in Fusarium proliferatum colonization and fumonisin content in the grain. Finally, root development was markedly promoted after B3 inoculation, and the yield improved by 48.60%. The result of field experiments showed that the incidence of RSRD and the fumonisin content were observably reduced in rice receiving B3, by 24.41% and 37.87%, respectively. CONCLUSION: The endophytic fungus Phomopsis liquidambaris B3 may become an effective tool to relieve rice spikelet rot disease. © 2020 Society of Chemical Industry.


Assuntos
Endófitos/fisiologia , Fusarium/fisiologia , Oryza/crescimento & desenvolvimento , Phomopsis/fisiologia , Doenças das Plantas/imunologia , Catecol Oxidase/genética , Catecol Oxidase/imunologia , Resistência à Doença , Fumonisinas/metabolismo , Oryza/genética , Oryza/imunologia , Oryza/microbiologia , Peroxidase/genética , Peroxidase/imunologia , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/imunologia , Raízes de Plantas/genética , Raízes de Plantas/imunologia , Raízes de Plantas/microbiologia , Superóxido Dismutase/genética , Superóxido Dismutase/imunologia
15.
Fungal Genet Biol ; 136: 103301, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31765708

RESUMO

The endophytic fungus Phomopsis liquidambaris efficiently promotes the nitrogen metabolism and growth of host plants such as rice and peanut. However, a lack of genetic tools limits further research regarding the mechanisms of interaction between P. liquidambaris and its host plants. Herein, a CRISPR/Cas9 system for targeted gene disruption in this strain was first constructed and optimized. The knock-out efficiency increased to over 60% when the ku70 or ku80 gene (involved in nonhomologous end-joining, NHEJ) was disrupted. Furthermore, the CRISPR/Cas9 system was applied to disrupt the PmkkA gene, encoding a mitogen-activated protein kinase kinase (MAPKK) in the cell-wall integrity (CWI) MAPK pathway of the strain. The ΔPmkkA mutant strain induced higher reactive oxygen species (ROS) production, chitinase activity and glucanase activity in rice seedlings than wild-type P. liquidambaris (WT), resulting in growth inhibition and strong resistance on rice. These results suggested that the PmkkA gene is crucial during the interaction with rice and may play a role in inhibiting the immune system of host plants. The CRISPR-Cas9 system will be of great use for the study of the interaction between P. liquidambaris and its host plants.


Assuntos
Ascomicetos/enzimologia , Ascomicetos/genética , Sistemas CRISPR-Cas , Interações entre Hospedeiro e Microrganismos , Quinases de Proteína Quinase Ativadas por Mitógeno/genética , Oryza/crescimento & desenvolvimento , Oryza/microbiologia , Parede Celular/metabolismo , Endófitos , Proteínas Fúngicas/genética , Técnicas de Inativação de Genes , Genes Fúngicos , Autoantígeno Ku/genética , Mutação , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/genética
16.
Crit Rev Biotechnol ; 40(1): 31-45, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31656090

RESUMO

Phytoremediation uses plants and associated microbes to remove pollutants from the environment and is considered a promising bioremediation method. Compared with well-described single contaminant treatments, the number of studies reporting phytoremediation of soil mixed pollutants has increased recently. Endophytes, including bacteria and fungi, exhibit beneficial traits for the promotion of plant growth, stress alleviation, and biodegradation. Moreover, endophytes either directly or indirectly assist host plants to survive high concentrations of organic and inorganic pollutants in the soil. Endophytic microorganisms can also regulate the plant metabolism in different ways, exhibiting a variety of physiological characteristics. This review summarizes the taxa and physiological properties of endophytic microorganisms that may participate in the detoxification of contaminant mixtures. Furthermore, potential biomolecules that may enhance endophyte mediated phytoremediation are discussed. The practical applications of pollutant-degrading endophytes and current strategies for applying this valuable bio-resource to soil phytoremediation are summarized.


Assuntos
Endófitos/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Biodegradação Ambiental , Metais/metabolismo , Compostos Orgânicos/metabolismo
17.
Plant Cell Environ ; 42(12): 3208-3226, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31373013

RESUMO

The role of flowering in root-fungal symbiosis is not well understood. Because flowering and fungal symbionts are supported by carbohydrates, we hypothesized that flowering modulates root-beneficial fungal associations through alterations in carbohydrate metabolism and transport. We monitored fungal colonization and soluble sugars in the roots of Arabidopsis thaliana following inoculation with a mutualistic fungus Phomopsis liquidambari across different plant developmental stages. Jasmonate signalling of wild-type plants, sugar transport, and root invertase of wild-type and jasmonate-insensitive plants were exploited to assess whether and how jasmonate-dependent sugar dynamics are involved in flowering-mediated fungal colonization alterations. We found that flowering restricts root-fungal colonization and activates root jasmonate signalling upon fungal inoculation. Jasmonates reduce the constitutive and fungus-induced accumulation of root glucose and fructose at the flowering stage. Further experiments with sugar transport and metabolism mutant lines revealed that root glucose and fructose positively influence fungal colonization. Diurnal, jasmonate-dependent inhibitions of sugar transport and soluble invertase activity were identified as likely mechanisms for flowering-mediated root sugar depletion upon fungal inoculation. Collectively, our results reveal that flowering drives root-fungus cooperation loss, which is related to jasmonate-dependent root soluble sugar depletion. Limiting the spread of root-fungal colonization may direct more resources to flower development.


Assuntos
Ascomicetos/fisiologia , Ciclopentanos/metabolismo , Flores/fisiologia , Oxilipinas/metabolismo , Raízes de Plantas/microbiologia , Açúcares/metabolismo , Simbiose/fisiologia , Arabidopsis/microbiologia , Ascomicetos/crescimento & desenvolvimento , Transporte Biológico , Ritmo Circadiano/fisiologia , Frutose/metabolismo , Glucose/metabolismo , Floema/metabolismo , Raízes de Plantas/enzimologia , Transdução de Sinais , Solubilidade , beta-Frutofuranosidase/metabolismo
18.
Appl Microbiol Biotechnol ; 103(15): 6041-6059, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31227866

RESUMO

Filamentous fungi can produce many valuable secondary metabolites; among these fungi, endophytic fungi play an ecological role in mutualistic symbiosis with plants, including promoting plant growth, disease resistance, and stress resistance. However, the biosynthesis of most secondary metabolites remains unclear, and knowledge of the interaction mechanisms between endophytes and plants is still limited, especially for some novel fungi, due to the lack of genetic manipulation tools for novel species. Herein, we review the newly discovered strategies of gene disruption, such as the CRISPR-Cas9 system, the site-specific recombination Cre/loxP system, and the I-SceI endonuclease-mediated system in filamentous fungi. Gene expression systems contain using integration of target genes into the genome, host-dependent expression cassette construction depending on the host, a host-independent, universal expression system independent of the host, and reporter-guided gene expression for filamentous fungi. Furthermore, the Newly CRISPRi, CRISPRa, and the selection markers were also discussed for gene disruption and gene expression were also discussed. These studies lay the foundation for the biosynthesis of secondary metabolites in these organisms and aid in understanding the ecological function of filamentous fungi.


Assuntos
Fungos/genética , Técnicas de Inativação de Genes/métodos , Genética Microbiana/métodos , Fungos/metabolismo , Redes e Vias Metabólicas/genética , Metabolismo Secundário
19.
J Sci Food Agric ; 99(4): 1898-1907, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30267426

RESUMO

BACKGROUND: The continuous cropping of peanuts is a primary cause of yield and quality loss. Solutions to this problem should be therefore developed to ensure the sustainability of peanut production. RESULTS: In this study, colonization by the endophytic fungus Phomopsis liquidambari was detected, which led to significantly improved rhizosphere soil microenvironment, enhanced N, P and K assimilation and suppressed incidence of peanut disease. Statistical analysis demonstrated that the yield enhancement was significantly correlated with improvement of the rhizosphere soil microenvironment and the peanut's physiological status by P. liquidambari colonization. In addition, P. liquidambari colonization also significantly improved peanut quality. CONCLUSION: Our results indicate that the practical application of the endophytic fungus P. liquidambari has a strong potential to alleviate the obstacles associated with continuous peanut cropping under field conditions. © 2018 Society of Chemical Industry.


Assuntos
Arachis/microbiologia , Ascomicetos/crescimento & desenvolvimento , Endófitos/crescimento & desenvolvimento , Doenças das Plantas/prevenção & controle , Arachis/química , Arachis/crescimento & desenvolvimento , Arachis/metabolismo , Nitrogênio/análise , Nitrogênio/metabolismo , Nutrientes/análise , Nutrientes/metabolismo , Doenças das Plantas/microbiologia , Potássio/análise , Potássio/metabolismo , Rizosfera , Microbiologia do Solo
20.
J Sci Food Agric ; 99(13): 5899-5909, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31225657

RESUMO

BACKGROUND: Most allelochemicals are secondary products released from root excretions or plant residues that accumulate in continuous cropping systems and cause severe decline in peanut yield. Resveratrol is a plant-derived stilbene that is released from peanut residues and accumulates in the soil; however, its allelopathic effects on peanut production are overlooked. Effective management solutions need to be developed to relieve allelopathy caused by soil resveratrol. Here, the biodegradation of resveratrol by the fungal endophyte Phomopsis liquidambari was investigated in a mineral salt medium and a soil trial. Resveratrol and its metabolites (produced by degradation by P. liquidambari) were detected by high-performance liquid chromatography-mass spectrometry (HPLC-MS). RESULTS: Resveratrol released from peanut residues reached a maximum concentration of 0.18 µg g-1 soil in litterbag experiments. Exogenous resveratrol inhibited peanut growth, nodule formation, and soil dehydrogenase activity, and reduced the soil microbial biomass carbon content and bacterial abundance, indicating an allelopathic role in peanut growth. More than 97% of the resveratrol was degraded within 72 and 168 h by P. liquidambari in pure culture and soil conditions, respectively. Resveratrol was first cleaved to 3,5-dihydroxybenzaldehyde and 4-hydroxybenzaldehyde, which were subsequently oxidized into 3,5-dihydroxybenzoic acid and 4-hydroxybenzoic acid, respectively. Fungal resveratrol cleavage oxygenase and the related gene expression were enhanced when P. liquidambari was induced by the resveratrol during the incubation. CONCLUSION: Our results indicate that the practical application of the fungal endophyte P. liquidambari has strong potential for biodegrading soil resveratrol, which can cause allelopathy in peanut continuous cropping systems. © 2019 Society of Chemical Industry.


Assuntos
Arachis/química , Ascomicetos/metabolismo , Endófitos/metabolismo , Feromônios/metabolismo , Resveratrol/metabolismo , Arachis/metabolismo , Arachis/microbiologia , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/isolamento & purificação , Biodegradação Ambiental , Feromônios/análise , Feromônios/farmacologia , Resveratrol/análise , Resveratrol/farmacologia , Solo/química , Microbiologia do Solo
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