scholarly journals Analysis of small RNA silencing in Zymoseptoria tritici – wheat interactions

2018 ◽  
Author(s):  
Graeme J. Kettles ◽  
Bernhard J. Hofinger ◽  
Pingsha Hu ◽  
Carlos Bayon ◽  
Jason J. Rudd ◽  
...  
Keyword(s):  
Small Rna ◽  
Rna Virus ◽  
Control Measure ◽  
Pathogenic Fungi ◽  
Fungal Colonization ◽  
In Planta ◽  
Zymoseptoria Tritici ◽  
Mrna Targets ◽  
Fungal Genes

AbstractCross-kingdom small RNA (sRNA) silencing has recently emerged as a mechanism facilitating fungal colonization and disease development. Here we characterized RNAi pathways in Zymoseptoria tritici, a major fungal pathogen of wheat, and assessed their contribution to pathogenesis. Computational analysis of fungal sRNA and host mRNA sequencing datasets was used to define the global sRNA populations in Z. tritici and predict their mRNA targets in wheat. 389 in planta-induced sRNA loci were identified. sRNAs generated from some of these loci were predicted to target wheat mRNAs including those potentially involved in pathogen defense. However, molecular approaches failed to validate targeting of selected wheat mRNAs by fungal sRNAs. Mutant strains of Z. tritici carrying deletions of genes encoding key components of RNAi such as Dicer-like (DCL) and Argounate (AGO) proteins were generated, and virulence bioassays suggested that these are dispensable for full infection of wheat. Nonetheless, our results did suggest the existence of non-canonical DCL-independent pathway(s) for sRNA biogenesis in Z. tritici. dsRNA targeting essential fungal genes applied in vitro or generated from an RNA virus vector in planta in a procedure known as HIGS (Host-Induced Gene Silencing) was ineffective in preventing Z. tritici growth or disease. We also demonstrated that Z. tritici is incapable of dsRNA uptake. Collectively, our data suggest that RNAi approaches for gene function analyses in this fungal species and potentially also as a control measure may not be as effective as has been demonstrated for some other plant pathogenic fungi.

scholarly journals Potassium limitation promotes the Sweetgum-Clitopilus symbiosis

2020 ◽  
Author(s):  
long peng ◽  
Xiaoliang Shan ◽  
Yuzhan Yang ◽  
Yuchen Wang ◽  
Irina Druzhinina ◽  
...  
Keyword(s):  
Soluble Sugars ◽  
Potassium Uptake ◽  
Fungal Colonization ◽  
In Planta ◽  
Cortical Cells ◽  
Symbiotic Interaction ◽  
Reciprocal Transfer ◽  
Fungal Genes ◽  
Potassium Limitation

Several species of soil free-living saprotrophs can sometimes establish biotrophic symbiosis with plants, but the basic biology of this association remains largely unknown. Here, we investigate the symbiotic interaction between a common soil saprotroph, Clitopilus hobsonii (Agaricomycetes), and the American sweetgum (Liquidambar styraciflua). Notably, the colonized root cortical cells contain numerous microsclerotia-like structures. Fungal colonization led to increased plant growth and facilitated potassium uptake, particularly under potassium limitation (0.05 mM K+). The expression of plant genes related to potassium uptake is not altered during symbiosis, whereas the transcripts of three fungal genes encoding ACU, HAK, and SKC involved in K+ nutrition is found in colonized roots. We confirmed the K+ influx activities by expressing the ChACU and ChSKC genes into a yeast K+-uptake-defective mutant. Upregulation of the ChACU under 0.05 mM K+ and no K+ conditions was demonstrated in planta and in vitro compared to normal condition (5 mM K+). In addition, colonized plants displayed a larger accumulation of soluble sugars under 0.05 mM K+. The present study highlights that potassium limitation promotes this novel tree-fungus symbiosis mainly through a reciprocal transfer of additional carbon and potassium to both partners, and the role of dual soil saprotroph/symbiotroph in tree nutrition.

scholarly journals Using Commercial Compost as Control Measures against Cucumber Root-Rot Disease

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Kamel Kamal Sabet ◽  
Magdy Mohamed Saber ◽  
Mohamed Adel-Aziz El-Naggar ◽  
Nehal Samy El-Mougy ◽  
Hatem Mohamed El-Deeb ◽  
...  
Keyword(s):  
Root Rot ◽  
Control Measure ◽  
Disease Incidence ◽  
Pathogenic Fungi ◽  
Pythium Ultimum ◽  
Control Measures ◽  
Infested Soil ◽  
Fungal Isolates ◽  
Cucumber Root

Five commercial composts were evaluated to suppress the root-rot pathogens (Fusarium solani (Mart.) App. and Wr, Pythium ultimum Trow, Rhizoctonia solani Kuhn, and Sclerotium rolfsii Sacc.) of cucumber plants under in vitro and greenhouse conditions. In vitro tests showed that all tested unautoclaved and unfiltrated composts water extracts (CWEs) had inhibitor effect against pathogenic fungi, compared to autoclaved and filtrated ones. Also, the inhibitor effects of 40 bacteria and 15 fungi isolated from composts were tested against the mycelial growth of cucumber root-rot pathogens. Twenty two bacteria and twelve fungal isolates had antagonistic effect against root-rot pathogens. The antagonistic fungal isolates were identified as 6 isolates belong to the genus Aspergillus spp., 5 isolates belong to the genus Penicillium spp. and one isolate belong to the genus Chaetomium spp. Under greenhouse conditions, the obtained results in pot experiment using artificial infested soil with cucumber root-rot pathogens showed that the compost amended soil reduced the percentage of disease incidence, pathogenic fungi population, and improved the cucumber vegetative parameters as shoot length, root length, fresh weight, and dry weight. These results suggested that composts are consequently considered as control measure against cucumber root-rot pathogens.

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

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.

scholarly journals Antifungal Activity of Silver Ions and Nanoparticles on Phytopathogenic Fungi

Plant Disease ◽  
2009 ◽  
Vol 93 (10) ◽  
pp. 1037-1043 ◽  
Author(s):  
Young-Ki Jo ◽  
Byung H. Kim ◽  
Geunhwa Jung
Keyword(s):  
Antifungal Activity ◽  
Colony Formation ◽  
Magnaporthe Grisea ◽  
Silver Ions ◽  
Pathogenic Fungi ◽  
Chloride Ions ◽  
Plant Diseases ◽  
Plant Pathogenic Fungi ◽  
In Planta

Silver in ionic or nanoparticle forms has a high antimicrobial activity and is therefore widely used for various sterilization purposes including materials of medical devices and water sanitization. There have been relatively few studies on the applicability of silver to control plant diseases. Various forms of silver ions and nanoparticles were tested in the current study to examine the antifungal activity on two plant-pathogenic fungi, Bipolaris sorokiniana and Magnaporthe grisea. In vitro petri dish assays indicated that silver ions and nanoparticles had a significant effect on the colony formation of these two pathogens. Effective concentrations of the silver compounds inhibiting colony formation by 50% (EC50) were higher for B. sorokiniana than for M. grisea. The inhibitory effect on colony formation significantly diminished after silver cations were neutralized with chloride ions. Growth chamber inoculation assays further confirmed that both ionic and nanoparticle silver significantly reduced these two fungal diseases on perennial ryegrass (Lolium perenne). Particularly, silver ions and nanoparticles effectively reduced disease severity with an application at 3 h before spore inoculation, but their efficacy significantly diminished when applied at 24 h after inoculation. The in vitro and in planta evaluations of silver indicated that both silver ions and nanoparticles influence colony formation of spores and disease progress of plant-pathogenic fungi. In planta efficacy of silver ions and nanoparticles is much greater with preventative application, which may promote the direct contact of silver with spores and germ tubes, and inhibit their viability.

scholarly journals EKSPLORASI DAN UJI VIRULENSI BAKTERI Bacillus sp. ENDOFIT JAGUNG TERHADAP PENYAKIT BUSUK PELEPAH JAGUNG

2020 ◽  
Vol 22 (2) ◽  
pp. 70-78
Author(s):  
Arum Saputri ◽  
Loekas Soesanto ◽  
Abu Umayah ◽  
Agus Sarjito
Keyword(s):  
Plant Height ◽  
Endophytic Bacteria ◽  
Block Design ◽  
Pathogenic Fungi ◽  
In Vitro Test ◽  
Bacillus Sp ◽  
In Planta ◽  
Fresh Weight ◽  
Randomized Block Design

[EXPLORATION AND VIRULENT TEST OF MAIZE ENDOPHYTE Bacillus sp. AGAINST MAIZE SHEATH BLIGHT]. Capability of endophytic bacterial, effectivity, and its effect on R. solani. and on maize seedlings growth were investigated from April 2018 to January 2019. Exploration of endophytes bacteria in maize was taken from Banyumas Regency (Sumbang, Kembaran, Baturraden) and Purbalingga Regency (Padamara, Bojongsari, Pratin). Taking plant samples using Purposive Random Sampling and Diagonal Sampling methods. Completely randomized design was used in in vitro test with 16 treatments repeated twice. Completely randomized block design was used in in planta experiment with 5 treatments repeated 5 times. The treatment consisted of control, fungiside (mankozeb), and 2 isolates of endophytes bacteria performing the best in vitro result. Variables observed included characteristics of endophytic bacteria and pathogenic fungi, inhibition diameter, incubation period, disease intensity, incidence of disease, AUDPC, plant height, leaf number, root length, plant fresh weight, canopy fresh weight, and root fresh weight. Resultshowed that the exploration obtained 15 endophytic Bacillus sp. isolates. The PD A.4 and BK A.1 isolates werw able to inhibit the growth of pathogenic fungi in-vitro by 56.93 and 51.5%, respectively. The soaking treatment using BK A1 was able to reduce disease intensity by 59.377%, and AUDPC value 34.19%. Endophytic bacteria influence plant height, plant fresh weight, canopy fresh weight, and fresh weight of roots respectively as 89.17 cm, 126.06 g, 106.67 g and 19.4 g.

scholarly journals Short 5′UTR enables optimal translation of plant virus tricistronic RNA via leaky scanning

2021 ◽  
Author(s):  
Yuji Fujimoto ◽  
Takuya Keima ◽  
Masayoshi Hashimoto ◽  
Yuka Hagiwara-Komoda ◽  
Naoi Hosoe ◽  
...  
Keyword(s):  
Rna Virus ◽  
Open Reading Frames ◽  
Regulation Mechanism ◽  
Translation Efficiency ◽  
In Planta ◽  
Leaky Scanning ◽  
Kozak Sequence ◽  
Movement Proteins ◽  
Conserved Gene

Regardless of the general model of translation in eukaryotic cells, a number of studies suggested that many of mRNAs encode multiple proteins. Leaky scanning, which supplies ribosomes to downstream open reading frames (ORFs) by read-through of upstream ORFs, is the most major regulatory mechanism to translate polycistronic mRNAs. However, the general regulatory factors controlling leaky scanning and their biological relevance have rarely been elucidated, with exceptions such as the Kozak sequence. Here, we have analyzed the strategy of a plant RNA virus to translate three movement proteins from a single RNA molecule through leaky scanning. The in planta and in vitro results indicate that significantly shorter 5′ UTR of the most upstream ORF promotes leaky scanning, potentially finetuning the translation efficiency of the three proteins in a single RNA molecule to optimize viral propagation. Moreover, in plant endogenous mRNAs, we found that shorter UTRs were more frequently observed in uORFs of polycistronic mRNAs. We propose that the promotion of leaky scanning induced by a short 5′ UTR (LISH), together with the Kozak sequence, is a conserved gene regulation mechanism not only in viruses but also in eukaryotes.

scholarly journals Alcohol Oxidase Is a Novel Pathogenicity Factor for Cladosporium fulvum, but Aldehyde Dehydrogenase Is Dispensable

2001 ◽  
Vol 14 (3) ◽  
pp. 367-377 ◽  
Author(s):  
G. Segers ◽  
N. Bradshaw ◽  
D. Archer ◽  
K. Blissett ◽  
R. P. Oliver
Keyword(s):  
Hansenula Polymorpha ◽  
Infected Plant ◽  
Alcohol Oxidase ◽  
Carbon Starvation ◽  
Cladosporium Fulvum ◽  
In Planta ◽  
Western Blots ◽  
Pathogenicity Factor ◽  
Fungal Genes

Cladosporium fulvum is a mitosporic ascomycete pathogen of tomato. A study of fungal genes expressed during carbon starvation in vitro identified several genes that were up regulated during growth in planta. These included genes predicted to encode acetaldehyde dehydrogenase (Aldh1) and alcohol oxidase (Aox1). An Aldh1 deletion mutant was constructed. This mutant lacked all detectable ALDH activity, had lost the ability to grow with ethanol as a carbon source, but was unaffected in pathogenicity. Aox1 expression was induced by carbon starvation and during the later stages of infection. The alcohol oxidase enzyme activity has broadly similar properties (Km values, substrate specificity, pH, and heat stability) to yeast enzymes. Antibodies raised to Hansenula polymorpha alcohol oxi-dase (AOX) detected antigens in Western blots of starved C. fulvum mycelium and infected plant material. Antigen reacting with the antibodies was localized to organelles resembling peroxisomes in starved mycelium and infected plants. Disruption mutants of Aox1 lacked detectable AOX activity and had markedly reduced pathogenicity as assayed by two different measures of fungal growth. These results identify alcohol oxidase as a novel pathogenicity factor and are discussed in relation to peroxisomal metabolism of fungal pathogens during growth in planta.

scholarly journals Nitrogen fertilizer-regulated plant-fungi interaction is related to root invertase-induced hexose generation

2020 ◽  
Vol 96 (8) ◽  
Author(s):  
Kai Sun ◽  
Wei Zhang ◽  
Jie Yuan ◽  
Shi-Li Song ◽  
Hao Wu ◽  
...  
Keyword(s):  
External Disturbance ◽  
Invertase Activity ◽  
Fungal Colonization ◽  
In Planta ◽  
N Application ◽  
Endophytic Colonization ◽  
Chemical Treatments ◽  
Plant Fungi ◽  
Soluble Acid

ABSTRACT The mechanisms underlying nitrogen (N)-regulated plant-fungi interactions are not well understood. N application modulates plant carbohydrate (C) sinks and is involved in the overall plant-fungal association. We hypothesized that N regulates plant-fungi interactions by influencing the carbohydrate metabolism. The mutualistic fungus Phomopsis liquidambaris was found to prioritize host hexose resources through in vitro culture assays and in planta inoculation. Rice-Ph. liquidambaris systems were exposed to N gradients ranging from N-deficient to N-abundant conditions to study whether and how the sugar composition was involved in the dynamics of N-mediated fungal colonization. We found that root soluble acid invertases were activated, resulting in increased hexose fluxes in inoculated roots. These fluxes positively influenced fungal colonization, especially under N-deficient conditions. Further experiments manipulating the carbohydrate composition and root invertase activity through sugar feeding, chemical treatments and the use of different soil types revealed that the external disturbance of root invertase could reduce endophytic colonization and eliminate endophyte-induced host benefits under N-deficient conditions. Collectively, these results suggest that the activation of root invertase is related to N deficiency-enhanced endophytic colonization via increased hexose generation. Certain combinations of farmland ecosystems with suitable N inputs could be implemented to maximize the benefits of plant-fungi associations.

scholarly journals CROSS APPLICATION OF ENTOMOPATHOGENIC FUNGI RAW SECONDARY METABOLITES FOR CONTROLLING FUSARIUM WILT OF CHILI SEEDLINGS

2021 ◽  
Vol 21 (2) ◽  
pp. 82-90
Author(s):  
Loekas Soesanto ◽  
Lintang Yunita Sari ◽  
Endang Mugiastuti ◽  
Abdul Manan
Keyword(s):  
Secondary Metabolites ◽  
Plant Height ◽  
Fusarium Wilt ◽  
Entomopathogenic Fungi ◽  
Root Length ◽  
Block Design ◽  
Pathogenic Fungi ◽  
In Vitro Test ◽  
In Planta

Cross application of entomopathogenic fungi raw secondary metabolites for controlling fusarium wilt of chili seedlings. Theresearch aimed to determine the effect of entomopathogenic fungi raw secondary metabolites on fusarium wilt on chili plants and on growth of chili. In vitro test used a Completely Randomized Design with 5 treatments and 5 replicate and in planta using a Randomized Block Design with 5 treatments and 5 replicatie including control, secondary metabolites of Beauveria bassiana B10, B. bassiana B16, Metarhizium anisopliae M16, dan Lecanicillium lecanii L16. Variables observed included inhibition ability, incubation period, desease intensity, plant height, root length, and phenolic compounds (tannins, saponin, and hydroquinone) content qualitatively. The results showed that secondary metabolites of B. bassiana B10, B. bassiana B16, M. anisopliae M16, and L. lecanii L16 were able to inhibit growth of Fusarium oxysporum f.sp. capsici by 50.62; 50,64; 48,62; 56.62%, respectively, extend incubation periods of 71.05; 73,38; 64.89; and 68.57%, respectively, suppress disease intensity by 99.99; 99.99; 99.99; and 99.99%, respectively, can increase plant height by 15.22; 18.8; 21.14; 21.69%, respectively, increasing the root length by 22.61; 25,71; 26,34; 33.50%, respectively, and can increase the content of tannins, saponins and hydroquinone compounds qualitatively compared to controls. The secondary metabolites of enthomopathogenic fungi could be used as organic control for soilborne pathogenic fungi.

scholarly journals In planta Activity of Novel Copper(II)-Based Formulations to Inhibit the Esca-Associated Fungus Phaeoacremonium minimum in Grapevine Propagation Material

2021 ◽  
Vol 12 ◽  
Author(s):  
Enrico Battiston ◽  
Stéphane Compant ◽  
Livio Antonielli ◽  
Vincenzo Mondello ◽  
Christophe Clément ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Defense Responses ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Fungal Colonization ◽  
Post Inoculation ◽  
In Planta ◽  
Experimental Treatments ◽  
Propagation Material

Grapevine trunk diseases (GTDs) are a serious and growing threat to vineyards worldwide. The need for innovative control tools persists since pesticides used against some GTDs have been banned and only methods to prevent infections or to reduce foliar symptoms have been developed so far. In this context, the application of imaging methods, already applied to study plant–microbe interactions, represents an interesting approach to understand the effect of experimental treatments applied to reduce fungal colonization, on GTD-related pathogens activity. To this aim, trials were carried out to evaluate the efficacy of copper-based treatments, formulated with hydroxyapatite (HA) as co-adjuvant with innovative delivery properties, loaded with two different copper(II) compounds (tribasic sulfate and sulfate pentahydrate), and applied to grapevine propagation material to inhibit fungal wood colonization. The treated rootstock (Vitis berlandieri × Vitis riparia cv. K5BB) and scion cuttings (Vitis vinifera L., cv. Chardonnay) had been inoculated with a strain of Phaeoacremonium minimum (Pmi) compared to uninoculated rootstocks. Experimental treatments were applied during the water-soaking process, comparing the copper(II) compounds pure or formulated with HA, to hydrate the cuttings. After callusing, grafted vines were grown under greenhouse conditions in a nursery and inoculated with Pmi::gfp7 or with Pmi wild-type. Fifteen weeks post-inoculation, woody tissues close to the inoculation site were sampled to evaluate the efficiency of the treatments by studying the plant–microbe interaction by confocal laser scanning microscopy (CLSM). Copper and further elements were also quantified in the same tissues immediately after the treatments and on the CLSM samples. Finally, the grapevine defense responses were studied in the leaves of cuttings treated with the same formulations. The present investigation confirmed the relevant interaction of Pmi and the related transformed strain on the vascular tissues of grafted vines. Furthermore, in vitro assay revealed (i) the fungistatic effect of HA and the reduced effect of Cu fungicide when combined with HA. In planta assays showed (ii) the reduction of Pmi infection in propagation material treated with HA-Cu formulations, (iii) the movement of HA-Cu formulations inside the plant tissues and their persistence over time, and (iv) the plant defense reaction following the treatment with pure HA or Cu, or combined.

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