CHANGES IN GERMINATION TYPE IN SOME USTILAGO SPECIES CAUSED BY AN UNIDENTIFIED VOLATILE SUBSTANCE

1966 ◽  
Vol 44 (2) ◽  
pp. 163-170 ◽  
Author(s):  
J. Nielsen
Keyword(s):  
Host Plants ◽  
Pathogenic Fungi ◽  
Volatile Substance ◽  
Host Tissue ◽  
Smut Fungi ◽  
Solid Compounds

An unidentified volatile substance, released by smut fungi, their host plants, and facultative pathogenic fungi, changed the germination type from sporidial to mycelial in Ustilago kolleri, U. avenae, U. hordei, and U. nigra. Imidazole caused similar changes. U. maydis did not respond to either the gas or imidazole. These compounds increase sexual affinity, which is expressed by fusion of compatible promycelial cells. The gas and similarly acting solid compounds seem to be responsible for the change in germination type of spores that germinate on host tissue or in the soil, thereby immediately initiating the parasitic dikaryophase. The importance of high sexual affinity for the maintenance of the dikaryophase of smut fungi both on artificial media and in the host is discussed.

Use of Freeze Substitution for TEM Studies of Fungal Spores

2000 ◽  
Vol 6 (S2) ◽  
pp. 684-685 ◽  
Author(s):  
C. W. Minis ◽  
E. A. Richardson
Keyword(s):  
Gold Standard ◽  
Fungal Spores ◽  
Freeze Substitution ◽  
Pathogenic Fungi ◽  
Rust Fungi ◽  
Smut Fungi ◽  
Plant Pathogenic Fungi ◽  
Dialysis Membrane ◽  
Direct Exposure ◽  
Fungal Hyphae

Since its initial use to fix fungal hyphae (1), plunge freezing followed by freeze substitution has become the “gold standard” for TEM studies of fungal hyphae and spores. In this presentation we discuss results we have obtained using plunge freezing and freeze substitution to fix various types of spores produced by plant pathogenic fungi. Examples include basidiospores and aeciospores of rust fungi, teliospores of rust and smut fungi and conidia of a variety of ascomycetes and deuteromycetes.Generally speaking, plunge freezing followed by freeze substitution usually yields best results when spore diameter does not exceed 10-15 μm. However, in a number of cases we (2) have obtained good to excellent results with much larger spores. A key to good freezing appears to be direct exposure of spores to liquid propane during plunging. We have had best results by placing spores on small pieces of dialysis membrane and then plunging these membranes. In most cases the spores remain attached to membranes throughout the freezing, substitution, infiltration and embedment procedures.

scholarly journals The microscopic pathogenic fungi of the Łęczna-Włodawa Lake District. II. The list of species

2014 ◽  
Vol 24 (2) ◽  
pp. 125-171 ◽  
Author(s):  
Wiesław Mułenko
Keyword(s):  
New Species ◽  
Rare Species ◽  
Host Plants ◽  
Pathogenic Fungi ◽  
Lake District ◽  
New Host ◽  
Parasitic Fungi

The paper presents the taxonomic list and localities of parasitic fungi coDected from Łęczna-Włodawa Lake District in 1981-1984. Among them there is a noumerous group of new species for Poland, rare species and the species colonizing new host plants.

scholarly journals A cell surface-exposed protein complex with an essential virulence function in Ustilago maydis

2021 ◽  
Author(s):  
Nicole Ludwig ◽  
Stefanie Reissmann ◽  
Kerstin Schipper ◽  
Carla Gonzalez ◽  
Daniela Assmann ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Protein Complex ◽  
Pathogenic Bacteria ◽  
Constitutive Expression ◽  
Pathogenic Fungi ◽  
Ustilago Maydis ◽  
Effector Proteins ◽  
Host Cells ◽  
Smut Fungi ◽  
Living Plant

AbstractPlant pathogenic fungi colonizing living plant tissue secrete a cocktail of effector proteins to suppress plant immunity and reprogramme host cells. Although many of these effectors function inside host cells, delivery systems used by pathogenic bacteria to translocate effectors into host cells have not been detected in fungi. Here, we show that five unrelated effectors and two membrane proteins from Ustilago maydis, a biotrophic fungus causing smut disease in corn, form a stable protein complex. All seven genes appear co-regulated and are only expressed during colonization. Single mutants arrest in the epidermal layer, fail to suppress host defence responses and fail to induce non-host resistance, two reactions that likely depend on translocated effectors. The complex is anchored in the fungal membrane, protrudes into host cells and likely contacts channel-forming plant plasma membrane proteins. Constitutive expression of all seven complex members resulted in a surface-exposed form in cultured U. maydis cells. As orthologues of the complex-forming proteins are conserved in smut fungi, the complex may become an interesting fungicide target.

scholarly journals Phenolic degradation by catechol dioxygenases is associated with pathogenic fungi with a necrotrophic lifestyle in the Ceratocystidaceae

2022 ◽  
Author(s):  
Nicole C Soal ◽  
Martin H A Coetzee ◽  
Magriet A van der Nest ◽  
Almuth Hammerbacher ◽  
Brenda D Wingfield
Keyword(s):  
Host Plants ◽  
Plant Defence ◽  
Gene Copy Number ◽  
Positive Association ◽  
Pathogenic Fungi ◽  
Fungal Species ◽  
Gene Copy ◽  
Highly Pathogenic ◽  
Genes Encoding ◽  
Catechol Dioxygenases

Abstract Fungal species of the Ceratocystidaceae grow on their host plants using a variety of different lifestyles, from saprophytic to highly pathogenic. Although many genomes of fungi in the Ceratocystidaceae are publicly available, it is not known how the genes that encode catechol dioxygenases (CDOs), enzymes involved in the degradation of phenolic plant defence compounds, differ among members of the Ceratocystidaceae. The aim of this study was therefore to identify and characterize the genes encoding CDOs in the genomes of Ceratocystidaceae representatives. We found that genes encoding CDOs are more abundant in pathogenic necrotrophic species of the Ceratocystidaceae and less abundant in saprophytic species. The loss of the CDO genes and the associated 3-oxoadipate catabolic pathway appears to have occurred in a lineage-specific manner. Taken together, this study revealed a positive association between CDO gene copy number and fungal lifestyle in Ceratocystidaceae representatives.

scholarly journals Examination of different fungicides against Macrophomina phaseolina in laboratory conditions

2020 ◽  
pp. 65-69
Author(s):  
Kitti Csüllög ◽  
Gábor Tarcali
Keyword(s):  
Host Plants ◽  
Hyphal Growth ◽  
Pathogenic Fungi ◽  
Macrophomina Phaseolina ◽  
Minor Effect ◽  
Efficient Treatment ◽  
The Third ◽  
The World ◽  
A Minor

In Hungary, sunflower is the third most important arable crop, which has a lot of pathogenic fungi. One of these fungi is the Macrophomina phaseolina, which is a well-known fungus in all over the world, since this pathogen has more than 700 host plants. In Hungary, several host plants can be found as well. The M. phaseolina produces microsclerotia, which can survive in the soil and residues for almost 10 years. For now, there is no efficient treatment against this pathogen because of this fungus, since it is extremely resistant and cannot be destroyed easily. The only effective treatment against the fungus is genetic defence. In this study, three different fungicides were tested in vitro against the fungus. The Mirage (prochloraz) seemed to be the most effective fungicide as it completely arrested the hyphal growth. In contrast, the Amistar Xtra (azoxystrobin and ciprochonazol) has only a minor effect on the growth of M. phaseolina. Thirdly, the Retengo (pyrachlostrobin) arrested the hyhpal growth of the fungus with 71% at 100 ppm, in other words, the use of this fungicide seems promising. 

scholarly journals Грибковые патогены в листьях нижнего яруса сортов томата Mary Gratefully и Tomiș

2021 ◽  
Author(s):  
Галина Белоусова ◽  
◽  
Надежда Михня ◽  
Keyword(s):  
Molecular Diagnostics ◽  
Nested Pcr ◽  
Host Plants ◽  
Pathogenic Fungi ◽  
Causal Agent ◽  
Tomato Cultivars ◽  
Myrothecium Roridum ◽  
Open Fields

Pathogenic fungi are the cause of various diseases of crops. Phytopathogens infect seeds as well as the host-plants in the course of the whole duration of their ontogenesis. Plants are infected when grown in greenhouses or in open fields by a single causal agent or several pathogenic fungi. In current study, a nested PCR protocol was applied for identification of tomatoes’ infection. An infestation with Alternaria spp. and Myrothecium roridum in the lowest leaves on the stem was stated using molecular diagnostics. The ‘Tomis’ and ‘Mary Gratefully’ tomato cultivars were used in current study. Alternaria spp. was iden-tified in each of the samples. The pathogen’s species was defined. Myrothecium roridum infested 10 sam-ples of the ‘Tomis’ genotype and 11 samples of the ‘Mary Gratefully’ genotype of the 12 samples.

scholarly journals In silico prediction and characterisation of secondary metabolite clusters in the plant pathogenic fungus Verticillium dahliae

2018 ◽  
Author(s):  
Xiaoqian Shi-Kunne ◽  
Roger de Pedro Jové ◽  
Jasper R.L. Depotter ◽  
Malaika Ebert ◽  
Michael F. Seidl ◽  
...  
Keyword(s):  
Secondary Metabolite ◽  
Verticillium Dahliae ◽  
In Silico ◽  
Host Plants ◽  
Biological Activities ◽  
Pathogenic Fungus ◽  
Pathogenic Fungi ◽  
Plant Pathogenic Fungi ◽  
In Silico Prediction ◽  
Close Proximity

ABSTRACTFungi are renowned producers of natural compounds, also known as secondary metabolites (SMs) that display a wide array of biological activities. Typically, the genes that are involved in the biosynthesis of SMs are located in close proximity to each other in so-called secondary metabolite clusters (SMCs). Many plant-pathogenic fungi secrete SMs during infection in order to promote disease establishment, for instance as cytocoxic compounds. Verticillium dahliae is a notorious plant pathogen that can infect over 200 host plants worldwide. However, the SM repertoire of this vascular pathogen remains mostly uncharted. To unravel the SM potential of V. dahliae, we performed in silico predictions and in-depth analyses of its SM clusters (SMC). We identified 25 potential SMCs in the V. dahliae genome, including loci that can be implicated in DHN-melanin, ferricrocin, triacetyl fusarinine and fujikurin production.

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