Differential interaction of the dark septate endophyte Cadophora sp. and fungal pathogens in vitro and in planta

ABSTRACT Dark septate endophytes (DSEs) present a group of widespread root-colonizing fungi. The role of these endophytes in ecosystems and their interactions with plant pathogens are not well understood. In the current study, we assessed the antagonistic potential of the model DSE Cadophora sp. against the tomato soilborne pathogens Rhizoctonia solani, Pythium aphanidermatum and Verticillium dahliae. To investigate their interactions, we conducted in vitro assays followed by a greenhouse experiments in which tomato plants were inoculated with different combinations of the DSE and pathogens. RNA accumulation of selected tomato pathogenesis-related genes and of Cadophora sp. genes with putative antifungal function was analyzed. Cadophora sp. inhibited the growth of the fungal pathogens in vitro and vice versa; a negative impact of the pathogens on the growth of the DSE was also detected. In roots, however, this mutual negative interaction could not be observed. Expression analyses of plant genes could not explain this differential effect, but among the Cadophora sp. genes analyzed, a gene coding for a chalcone synthase was downregulated in planta. The data indicate that plants can change the interaction between fungi and, therefore, in vitro detected antagonism does not necessarily reflect the situation inside the plant.

Download Full-text

Control Of Plant Diseases By An Allium-based Antimicrobial Formulation

10.20944/preprints202201.0091.v1 ◽

2022 ◽

Author(s):

Oladejo Oluwashina ◽

Jafargholi Imani

Keyword(s):

Fungal Pathogens ◽

Plant Pathogens ◽

Fruits And Vegetables ◽

Antimicrobial Properties ◽

Field Application ◽

Plant Diseases ◽

In Planta ◽

Xanthomonas Fragariae ◽

Alternaria Dauci

The objective of this work was to determine the antimicrobial properties of an allium-based antimicrobial formulation named VEG’LYS (https://phytoauxilium.com/) on the growth of plant pathogenic microorganisms such as fungi, oomycetes, and bacteria. Two anthracnose-related species of the fungal genus Colletotrichum, C. gloeosporioides, and C. fragariae, the oomycete Phytophthora cactorum and the bacterium Xanthomonas fragariae associated with strawberry plants and two fungi Alternaria dauci and Botrytis cinerea, associated with carrot plants were tested in vitro. In in planta experiments, A. dauci and B. cinerea were used.. VEG’LYS inhibited the growth of all plant pathogens tested. We found that both curative and preventive in planta treatments with VEG’LYS inhibited the growth of A. dauci and B. cinerea in carrot. Furthermore, after spraying VEG’LYS on carrot plants the expression of the Pathogenesis-related (PR) 10 gene correlated with the magnitude of infection both in treated and untreated plants. Additionally, it has been shown, that the field application of VEG’LYS on strawberry plants results in a reduction of bacterial and fungal pathogens of strawberry fruits stored in refrigerator. In summary, VEG’LYS is a potential resistance inducer that seems to be suitable for use in both curative and preventive treatments to reduce the diseases and rotting of fruits and vegetables caused by different plant pathogens.

Download Full-text

The Potential of Rhizoctonia-Like Fungi for the Biological Protection of Cereals against Fungal Pathogens

Plants ◽

10.3390/plants10020349 ◽

2021 ◽

Vol 10 (2) ◽

pp. 349

Author(s):

Dominik Bleša ◽

Pavel Matušinský ◽

Romana Sedmíková ◽

Milan Baláž

Keyword(s):

Biological Control ◽

Fungal Pathogens ◽

Plant Pathogens ◽

Higher Plants ◽

Fusarium Culmorum ◽

Suppressive Effect ◽

Plant Production ◽

Shoot Biomass ◽

Organic Substrates

The use of biological control is becoming a common practice in plant production. One overlooked group of organisms potentially suitable for biological control are Rhizoctonia-like (Rh-like) fungi. Some of them are capable of forming endophytic associations with a large group of higher plants as well as mycorrhizal symbioses. Various benefits of endophytic associations were proved, including amelioration of devastating effects of pathogens such as Fusarium culmorum. The advantage of Rh-like endophytes over strictly biotrophic mycorrhizal organisms is the possibility of their cultivation on organic substrates, which makes their use more suitable for production. We focused on abilities of five Rh-like fungi isolated from orchid mycorrhizas, endophytic fungi Serendipita indica, Microdochium bolleyi and pathogenic Ceratobasidium cereale to inhibit the growth of pathogenic F. culmorum or Pyrenophora teres in vitro. We also analysed their suppressive effect on wheat infection by F. culmorum in a growth chamber, as well as an effect on barley under field conditions. Some of the Rh-like fungi affected the growth of plant pathogens in vitro, then the interaction with plants was tested. Beneficial effect was especially noted in the pot experiments, where wheat plants were negatively influenced by F. culmorum. Inoculation with S. indica caused higher dry shoot biomass in comparison to plants treated with fungicide. Prospective for future work are the effects of these endophytes on plant signalling pathways, factors affecting the level of colonization and surviving of infectious particles.

Download Full-text

PHIALOMYCES MACROSPORUS REDUCES CERCOSPORA COFFEICOLA SURVIVAL ON SYMPTOMATIC COFFEE LEAVES

Coffee Science ◽

10.25186/cs.v14i1.1448 ◽

2019 ◽

Vol 14 (1) ◽

pp. 1

Author(s):

Marie Caroline Ferreira Laborde ◽

Deila Magna dos Santos Botelho ◽

Gabriel Alfonso Alvarez Rodriguez ◽

Mário Lúcio Vilela de Resende ◽

Marisa Vieira de Queiroz ◽

...

Keyword(s):

Plant Pathogens ◽

Disease Rate ◽

In Planta ◽

Necrotrophic Pathogen ◽

Initial Inoculum ◽

Saprobe Fungi ◽

Cercospora Coffeicola ◽

Brown Eye Spot

Saprobe fungi and necrotrophic pathogens share the same niche within crop stubble and the search for fungi non-pathogenic to plants that are able to displace the plant pathogens from its overwintering substrate contributes to the disease management. Brown eye spot (Cercospora coffeicola) is among the most important coffee diseases, it is caused by a necrotrophic pathogen that has decaying leaves as its major source of inoculum. We have screened saprobe fungi for the ability to reduce C. coffeicola sporulation and viability and determined the possible mechanisms involved in the observed biocontrol. A selected saprobe fungus, Phialomyces macrosporus, reduced the pathogen’s viability by 40% both in vitro and in vivo. The fungus acts through antibiosis and competition for nutrients. It produced both volatile and non-volatile compounds that inhibited C. coffeicola growth, sporulation, and viability. It also produced the tissue maceration enzyme (polygalacturonase), which reduces the pathogen both in detached leaves or in planta. The reduction in the fungal viability either by the saprobe fungus or its polygalacturonase-fraction supernatant resulted in the reduction of the disease rate. Therefore, P. macrosporus is a potential microbial agent that can be used in an integrated management of brown eye spot through the reduction of the initial inoculum of the pathogen that survives and builds up in infected leaves.

Download Full-text

Evaluation of in-vitro methods to select effective streptomycetes against toxigenic fusaria

PeerJ ◽

10.7717/peerj.6905 ◽

2019 ◽

Vol 7 ◽

pp. e6905 ◽

Cited By ~ 5

Author(s):

Elena Maria Colombo ◽

Cristina Pizzatti ◽

Andrea Kunova ◽

Claudio Gardana ◽

Marco Saracchi ◽

...

Keyword(s):

Plant Pathogens ◽

Culture Media ◽

Screening Methods ◽

Dual Culture ◽

In Planta ◽

In Vitro Method ◽

In Vitro Methods ◽

Strain Diversity ◽

Fungal Plant Pathogens

Biocontrol microorganisms are emerging as an effective alternative to pesticides. Ideally, biocontrol agents (BCAs) for the control of fungal plant pathogens should be selected by an in vitro method that is high-throughput and is predictive of in planta efficacy, possibly considering environmental factors, and the natural diversity of the pathogen. The purpose of our study was (1) to assess the effects ofFusariumstrain diversity (N= 5) and culture media (N= 6) on the identification of biological control activity ofStreptomycesstrains (N= 20) againstFusariumpathogens of wheat in vitro and (2) to verify the ability of our in vitro screening methods to simulate the activity in planta. Our results indicate that culture media,Fusariumstrain diversity, and their interactions affect the results of an in vitro selection by dual culture assay. The results obtained on the wheat-based culture media resulted in the highest correlation score (r= 0.5) with the in planta root rot (RR) inhibition, suggesting that this in vitro method was the best predictor of in planta performance of streptomycetes against Fusarium RR of wheat assessed as extension of the necrosis on the root. Contrarily, none of the in vitro plate assays using the media tested could appropriately predict the activity of the streptomycetes against Fusarium foot rot symptoms estimated as the necrosis at the crown level. Considering overall data of correlation, the activity in planta cannot be effectively predicted by dual culture plate studies, therefore improved in vitro methods are needed to better mimic the activity of biocontrol strains in natural conditions. This work contributes to setting up laboratory standards for preliminary screening assays ofStreptomycesBCAs against fungal pathogens.

Download Full-text

Analysis of expressed sequence tags derived from the endophytic fungus Neotyphodium lolii grown in vitro and in association with its host plant perennial ryegrass

NZGA: Research and Practice Series ◽

10.33584/rps.13.2006.3135 ◽

2007 ◽

Vol 13 ◽

pp. 501-504

Author(s):

R. Johnson ◽

A. Khan ◽

C. Voisey ◽

S. Bassett ◽

C. Gaborit ◽

...

Keyword(s):

Expressed Sequence Tags ◽

Virulence Genes ◽

In Planta ◽

Suppression Subtractive Hybridisation ◽

The Public ◽

Neotyphodium Lolii ◽

Subtractive Hybridisation ◽

Plant Genes ◽

Expressed Sequence

As a first step towards a functional genomics approach to gain a greater understanding of this important symbiosis, we have generated, sequenced and analysed two EST libraries from cultures of N. lolii and six in planta subtracted EST libraries enriched for differentially expressed genes. A total of 12871 ESTs were sequenced which, after filtering for quality, clustered into 1066 contigs and 3230 singletons to give a set of 4296 unique sequences or unigenes. BLASTX analysis revealed that 60% of fungal sequences derived from cultures were of unknown function with a sub-set of these corresponding to orphans. For the in planta-derived ESTs, most of the sequences with homologs in the public databases (98%) were of ryegrass origin. Comparisons made against fully sequenced genomes revealed that most fungal ESTs were homologous to genes present in both pathogenic and non-pathogenic ascomycete filamentous fungi, whereas the subtracted libraries comprised mostly plant genes. A range of sequences having significant homology to demonstrated pathogenicity/virulence genes in other fungal pathosystems were also identified, as well as some ESTs with proven roles in endophyte secondary metabolism. Keywords: ESTs, cDNA, Neotyphodium lolii, Lolium perenne, symbiosis, mutualism, suppression subtractive hybridisation

Download Full-text

A Microbial Fermentation Mixture Reduces Fusarium Head Blight and Promotes Grain Weight but does not impact Septoria tritici blotch

European Journal of Plant Pathology ◽

10.1007/s10658-021-02396-4 ◽

2021 ◽

Author(s):

Tony Twamley ◽

Mark Gaffney ◽

Angela Feechan

Keyword(s):

Fusarium Head Blight ◽

Fungal Pathogens ◽

Septoria Tritici Blotch ◽

Septoria Tritici ◽

Microbial Fermentation ◽

In Planta ◽

Head Blight ◽

Zymoseptoria Tritici ◽

The Impact

AbstractFusarium graminearum and Zymoseptoria tritici cause economically important diseases of wheat. F. graminearum is one of the primary causal agents of Fusarium head blight (FHB) and Z. tritici is the causal agent of Septoria tritici blotch (STB). Alternative control methods are required in the face of fungicide resistance and EU legislation which seek to cut pesticide use by 2030. Both fungal pathogens have been described as either hemibiotrophs or necrotrophs. A microbial fermentation-based product (MFP) was previously demonstrated to control the biotrophic pathogen powdery mildew, on wheat. Here we investigated if MFP would be effective against the non-biotrophic fungal pathogens of wheat, F. graminearum and Z. tritici. We assessed the impact of MFP on fungal growth, disease control and also evaluated the individual constituent parts of MFP. Antifungal activity towards both pathogens was found in vitro but MFP only significantly decreased disease symptoms of FHB in planta. In addition, MFP was found to improve the grain number and weight, of uninfected and F. graminearum infected wheat heads.

Download Full-text

Respuesta de biosurfactantes producidos por Pseudomonas fluorescens para el control de la gota de la papa Phytophthora infestans (Mont) de Bary, bajo condiciones controlada.

Ciencia y Tecnología Agropecuaria ◽

10.21930/rcta.vol11_num1_art:191 ◽

2010 ◽

Vol 11 (1) ◽

pp. 21

Author(s):

Hugo F. Rivera ◽

Erika P. Martínez ◽

Jairo A. Osorio ◽

Edgar Martínez

Keyword(s):

Late Blight ◽

Phytophthora Infestans ◽

Pseudomonas Fluorescens ◽

Negative Impact ◽

Potato Late Blight ◽

Pathogen Resistance ◽

Production Costs ◽

In Vitro Assays

Phytophthora infestans (Mont.) de Bary, agente causal de la gota de la papa, es considerado la principal limitante de la producción de este cultivo en Colombia. El control habitual del patógeno se realiza con fungicidas de tipo sistémico, que incrementan los costos de producción, pueden inducir la resistencia del patógeno y tiene un impacto negativo en el ambiente. Por tanto, se llevó a cabo este estudio con el propósito de buscar alternativas amigables con el ambiente, que hagan parte de un paquete tecnológico eficaz de control. Dos cepas nativas de Psedomonas fluorescens (039T y 021V), provenientes de cultivos de papa, fueron evaluadas contra P. infestans. Las suspensiones bacterianas y los biosurfactantes parcialmente purificados (BPP), producidos por éstas (obtenidos en medio mínimo de sales con querosén), fueron aplicados sobre foliolos desprendidos en ensayos in vitro y experimentos in vivo en plantas de papa, en condiciones controladas en casa de malla. Los resultados demostraron la capacidad que tienen los biosurfactantes y las suspensiones bacterianas para controlar al patógeno, ya que el BPP 039T logró reducir el nivel de severidad de la enfermedad en 79,9% in vitro y 38,5% in vivo, mientras que el BPP 021V redujo en 78,7% in vitro y 30,2% in vivo. Las suspensiones bacterianas redujeron el nivel de severidad en 72,4% (039T) y 66,1% (021V) en las evaluaciones in vitro y 35% en los experimentos in vivo. Los resultados de esta investigación muestran el potencial que tienen los biosurfactantes para el control de la gota en Colombia. Evaluation of Biosurfactants Produced by Pseudomonas fluorescens for Potato Late Blight Control (Phytophthora infestans (Mont) de Bary) Under Controlled ConditionsPhytophthora infestans (Mont.) de Bary, causal agent of potato late blight is considered the main limiting pathogen for the production of this crop in Colombia. The usual control of the disease has been performed with systemic fungicides which increase production costs, can induce pathogen resistance and have a negative impact on the environment. Therefore, this study was carried out in order to find effective and environmentally friendly control alternatives for potato late blight. Two Pseudomonas fluorescens native strains (039T and 021V) isolated from potato crops were evaluated against P. infestans. Bacterial suspensions (obtained from minimal salts medium added with kerosene) and partially purified biosurfactants (BPP) were applied on detached leaflets for in vitro assays and on potato plants in greenhouse, for in vivo assays and the measure of inhibitory effect of the disease was assessed. The results showed the ability of P. fluorescens biosurfactants and bacterial suspensions to control the pathogen. BPP 039T was able to reduce the level of severity disease by 79.9% in vitro and 38.5% in vivo, whereas BPP 021V decreased 78.7% in vitro and 30.2% in vivo. Bacterial suspensions reduced the severity level in 72.4% (039T) and 66.1% (021V) in vitro assessments and 35% in the in vivo experiment. These results show the potential of P. fluorescens biosurfactants to control the potato late blight in Colombia.

Download Full-text

Chemical synthesis and characterization of a new quinazolinedione competitive antagonist for strigolactone receptors with an unexpected binding mode

Biochemical Journal ◽

10.1042/bcj20190288 ◽

2019 ◽

Vol 476 (12) ◽

pp. 1843-1856 ◽

Cited By ~ 1

Author(s):

Cyril Hamiaux ◽

Lesley Larsen ◽

Hui Wen Lee ◽

Zhiwei Luo ◽

Prachi Sharma ◽

...

Keyword(s):

In Silico ◽

Binding Mode ◽

Crystal Structure Analysis ◽

Tolfenamic Acid ◽

In Vitro Assays ◽

Inhibition Mechanism ◽

In Planta ◽

Competitive Antagonist ◽

In Silico Docking

Abstract Strigolactones (SLs) are multifunctional plant hormones regulating essential physiological processes affecting growth and development. In vascular plants, SLs are recognized by α/β hydrolase-fold proteins from the D14/DAD2 (Dwarf14/Decreased Apical Dominance 2) family in the initial step of the signaling pathway. We have previously discovered that N-phenylanthranilic acid derivatives (e.g. tolfenamic acid) are potent antagonists of SL receptors, prompting us to design quinazolinone and quinazolinedione derivatives (QADs and QADDs, respectively) as second-generation antagonists. Initial in silico docking studies suggested that these compounds would bind to DAD2, the petunia SL receptor, with higher affinity than the first-generation compounds. However, only one of the QADs/QADDs tested in in vitro assays acted as a competitive antagonist of SL receptors, with reduced affinity and potency compared with its N-phenylanthranilic acid ‘parent’. X-ray crystal structure analysis revealed that the binding mode of the active QADD inside DAD2's cavity was not that predicted in silico, highlighting a novel inhibition mechanism for SL receptors. Despite a ∼10-fold difference in potency in vitro, the QADD and tolfenamic acid had comparable activity in planta, suggesting that the QADD compensates for lower potency with increased bioavailability. Altogether, our results establish this QADD as a novel lead compound towards the development of potent and bioavailable antagonists of SL receptors.

Download Full-text

The In Vitro and In Planta Interspecies Interactions Among Rice-Pathogenic Burkholderia Species

Plant Disease ◽

10.1094/pdis-06-20-1252-re ◽

2021 ◽

Vol 105 (1) ◽

pp. 134-143

Author(s):

Namgyu Kim ◽

Mohamed Mannaa ◽

Juyun Kim ◽

Ji-Eun Ra ◽

Sang-Min Kim ◽

...

Keyword(s):

Inhibitory Activity ◽

Fluorescent Protein ◽

Antagonistic Activity ◽

In Vitro Assays ◽

Interspecies Interactions ◽

In Planta ◽

Burkholderia Glumae ◽

Burkholderia Species ◽

Green Fluorescent

Burkholderia glumae, B. plantarii, and B. gladioli are responsible for serious diseases in rice crops and co-occurrence among them has been reported. In this study, in vitro assays revealed antagonistic activity among these organisms, with B. gladioli demonstrating strong inhibition of B. glumae and B. plantarii. Strains of B. glumae and B. plantarii that express green fluorescent protein were constructed and used for cocultivation assays with B. gladioli, which confirmed the strong inhibitory activity of B. gladioli. Cell-free supernatants from each species were tested against cultures of counterpart species to evaluate the potential to inhibit bacterial growth. To investigate the inhibitory activity of B. gladioli on B. glumae and B. plantarii in rice, rice plant assays were performed and quantitative PCR (qPCR) assays were developed for in planta bacterial quantification. The results indicated that coinoculation with B. gladioli leads to significantly reduced disease severity and colonization of rice tissues compared with single inoculation with B. glumae or B. plantarii. This study demonstrates the interactions among three rice-pathogenic Burkholderia species and strong antagonistic activity of B. gladioli in vitro and in planta. The qPCR assays developed here could be applied for accurate quantification of these organisms from in planta samples in future studies.

Download Full-text

Inhibition of Phytophthora parasitica and P. capsici by Silver Nanoparticles Synthesized Using Aqueous Extract of Artemisia absinthium

Phytopathology ◽

10.1094/phyto-01-15-0006-r ◽

2015 ◽

Vol 105 (9) ◽

pp. 1183-1190 ◽

Cited By ~ 25

Author(s):

Mohammad Ali ◽

Bosung Kim ◽

Kevin D. Belfield ◽

David Norman ◽

Mary Brennan ◽

...

Keyword(s):

Silver Nanoparticles ◽

Aqueous Extract ◽

Dose Response ◽

Mycelial Growth ◽

Plant Pathogens ◽

Synthesis Methods ◽

In Planta ◽

Artemisia Absinthium ◽

Plant Disease Management

Application of nanoparticles for controlling plant pathogens is a rapidly emerging area in plant disease management, and nanoparticles synthesis methods that are economical and ecofriendly are extensively investigated. In this project, we investigated the potential of silver nanoparticles (AgNPs) synthesized with aqueous extract of Artemisia absinthium against several Phytophthora spp., which cause many economically important crop diseases. In in vitro dose-response tests conducted in microtiter plates, 10 µg ml−1 of AgNPs inhibited mycelial growth of P. parasitica, P. infestans, P. palmivora, P. cinnamomi, P. tropicalis, P. capsici, and P. katsurae. Detailed in vitro dose-response analyses conducted with P. parasitica and P. capsici revealed that AgNPs synthesized with A. absinthium extract were highly potent (IC50: 2.1 to 8.3 µg ml−1) and efficacious (100%) in inhibiting mycelial growth, zoospore germination, germ tube elongation, and zoospore production. Interestingly, AgNP treatment accelerated encystment of zoospores. Consistent with in vitro results, in planta experiments conducted in a greenhouse revealed that AgNP treatments prevented Phytophthora infection and improved plant survival. Moreover, AgNP in in planta experiments did not produce any adverse effects on plant growth. These investigations provide a simple and economical method for controlling Phytophthora with AgNP without affecting normal plant physiology.

Download Full-text