Topographical signaling for cell differentiation in the plant pathogenic fungus, Uromyces

1989 ◽  
Vol 47 ◽  
pp. 784-785
Author(s):  
H.C. Hoch
Keyword(s):  
Plant Pathogens ◽  
Developmental Process ◽  
Pathogenic Fungus ◽  
Host Cells ◽  
Subsequent Infection ◽  
Infection Structures ◽  
Rust Diseases ◽  
Fungal Plant Pathogens ◽  
Plant Signals ◽  
Important Structure

Fungal plant pathogens invade host cells with a variety of specialized infection structures, however, for most fungi the appressorium is developmentally the first and most important structure to be formed in preparation for host colonization. It must be positioned at an appropriate site on the host in a timely way so that subsequent infection can be assured. For fungi which cause rust diseases of plants, positioning the appressorium is the most critical stage because invasion of the host can occur only via the stomata. Uredospores of these fungi (e.g.,Uromyces appendiculatus) germinate and grow, directed by the leaf (bean) surface topography toward stomata where they cease growth and develop appressoria directly over the stomatal openings. Development of the appressorium is accompanied by ameboid-like migration of the cytoplasm into the ballooning hyphal tip, DNA synthesis and nuclear division, synthesis of several “differentiation” proteins, and a rearrangement of the cytoskeleton. An orderly succession of subsequent infection structures (e.g., infection pegs, vesicles) follow in a preprogrammed sequence once the initial developmental process has been started.My research goals have been to determine what feature(s) of the host plant signals infection structure formation and how the fungus perceives these signals.

Effectors of biotrophic fungal plant pathogens

2010 ◽  
Vol 37 (10) ◽  
pp. 913 ◽  
Author(s):  
Pamela H. P. Gan ◽  
Maryam Rafiqi ◽  
Adrienne R. Hardham ◽  
Peter N. Dodds
Keyword(s):  
Plant Tissue ◽  
Fungal Pathogen ◽  
Plant Pathogens ◽  
Plant Cells ◽  
Host Cells ◽  
Plant Proteins ◽  
Living Plant ◽  
Host Cytoplasm ◽  
Fungal Plant Pathogens ◽  
Biotrophic Fungi

Plant pathogenic biotrophic fungi are able to grow within living plant tissue due to the action of secreted pathogen proteins known as effectors that alter the response of plant cells to pathogens. The discovery and identification of these proteins has greatly expanded with the sequencing and annotation of fungal pathogen genomes. Studies to characterise effector function have revealed that a subset of these secreted pathogen proteins interact with plant proteins within the host cytoplasm. This review focuses on the effectors of intracellular biotrophic and hemibiotrophic fungal plant pathogens and summarises advances in understanding the roles of these proteins in disease and in elucidating the mechanism of fungal effector uptake into host cells.

Infection structures of biotrophic and hemibiotrophic fungal plant pathogens

2001 ◽  
Vol 2 (2) ◽  
pp. 101-108 ◽  
Author(s):  
Sarah E. Perfect ◽  
Jonathan R. Green
Keyword(s):  
Plant Pathogens ◽  
Infection Structures ◽  
Fungal Plant Pathogens

Analysis of differentiation and development of the specialized infection structures formed by biotrophic fungal plant pathogens using monoclonal antibodies

1995 ◽  
Vol 73 (S1) ◽  
pp. 408-417 ◽  
Author(s):  
Jonathan R. Green ◽  
Naomi A. Pain ◽  
Martin E. Cannell ◽  
Calum P. Leckie ◽  
Sharon McCready ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Plasma Membrane ◽  
Powdery Mildew ◽  
Plant Pathogens ◽  
Colletotrichum Lindemuthianum ◽  
Cdna Expression Library ◽  
Erysiphe Pisi ◽  
Infection Structures ◽  
Fungal Plant Pathogens

Monoclonal antibodies have been used to study the differentiation and development of the specialized infection structures formed in the Colletotrichum–bean and powdery mildew – pea interactions. In the Colletotrichum lindemuthianum – bean interaction, monoclonal antibodies have been used to show that the extracellular matrices associated with conidia, germ tubes, and appressoria differ in composition and that the extracellular glycoproteins are organized into specific regions of the fungal cell surface. Monoclonal antibody UB27 has been used to show that the plasma membrane of appressoria is differentiated into distinct domains, with the integral membrane glycoprotein identified by UB27 being excluded from the pore region. UB25 recognizes a glycoprotein located specifically in the cell wall/matrix of intracellular hyphae and is expressed only during the biotrophic phase of development. In the Erysiphe pisi – pea interaction, UB8 and UB10 identify glycoproteins specific to the haustorial plasma membrane within the haustorial complex. Monoclonal antibodies that recognize the extrahaustorial membrane have shown that this membrane contains specific components, as well as glycoproteins in common with the host plasma membrane. UB8 has been successfully used to isolate a gene sequence coding for the protein antigen, by immunoscreening a cDNA expression library prepared from infected epidermis. An antibody that recognizes the plant endoplasmic reticulum has been used to show that this structure reorganizes around the developing haustorial complex in pea epidermal cells. Key words: appressorium, biotrophy, Colletotrichum lindemuthianum, Erysiphe pisi, haustorium, monoclonal antibody, powdery mildew.

scholarly journals MoCpa1-mediated arginine biosynthesis is crucial for fungal growth, conidiation, and plant infection of Magnaporthe oryzae

2020 ◽  
Author(s):  
Osakina Aron ◽  
Min Wang ◽  
Anjago Wilfred Mabeche ◽  
Batool Wajjiha ◽  
Shuai Yang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Magnaporthe Oryzae ◽  
Plant Pathogens ◽  
De Novo ◽  
Pathogenic Fungi ◽  
Host Cells ◽  
Arginine Biosynthesis ◽  
Carbamoyl Phosphate ◽  
Genome Database ◽  
Fungal Plant Pathogens

AbstractArginine is an important amino acid involved in processes such as cell signal transduction, protein synthesis, and sexual reproduction. To understand the biological roles of arginine biosynthesis in pathogenic fungi, we used Cpa1, the carbamoyl phosphate synthase arginine-specific small chain subunit in Saccharomyces cerevisiae as a query to identify its ortholog in Magnaporthe oryzae genome database and named it MoCpa1. MoCpa1 is a 471-amino acid protein containing the CPSase_sm_chain domain and the GATase domain. MoCpa1 transcripts were highly expressed at the conidiation, early-infection, and late-infection stages of the fungus. Targeted deletion of MoCPA1 gene resulted in the ΔMocpa1 mutant exhibiting arginine auxotrophy on MM, confirming its role in de novo arginine biosynthesis. The ΔMocpa1 mutant presented significantly decreased sporulation with some of its conidia being defective in morphology. Furthermore, the ΔMocpa1 mutant was nonpathogenic on rice and barley leaves, which was a result of defects in appressorium-mediated penetration and restricted invasive hyphal growth within host cells. Addition of exogenous arginine partially rescued conidiation and pathogenicity defects on the barley and rice leaves, while introduction of MoCPA1 gene in ΔMocpa1 mutant fully complemented the lost phenotype. Further confocal microscopy examination revealed that MoCpa1 is localized in the mitochondria. In summary, our results demonstrate that MoCpa1-mediated arginine biosynthesis is crucial for fungal development, conidiation, appressorium formation and infection-related morphogenesis in M. oryzae, thus serving as an attractive target for mitigating obstinate fungal plant pathogens.

scholarly journals The polyphagous plant pathogenic fungus Botrytis cinerea encompasses host-specialized and generalist populations

2019 ◽  
Author(s):  
Alex Mercier ◽  
Florence Carpentier ◽  
Clémentine Duplaix ◽  
Annie Auger ◽  
Jean-Marc Pradier ◽  
...  
Keyword(s):  
Genetic Analysis ◽  
Botrytis Cinerea ◽  
Population Genetic ◽  
Plant Pathogens ◽  
Pathogenic Fungus ◽  
Spatial Optimization ◽  
Agricultural Landscapes ◽  
Host Specialization ◽  
Population Genetic Analysis ◽  
Fungal Plant Pathogens

AbstractThe host plant is often the main variable explaining population structure in fungal plant pathogens, because specialization contributes to reduce gene flow between populations associated with different hosts. Previous population genetic analysis revealed that French populations of the grey mould pathogen Botrytis cinerea were structured by hosts tomato and grapevine, suggesting host specialization in this highly polyphagous pathogen. However, these findings raised questions about the magnitude of this specialization and the possibility of specialization to other hosts. Here we report specialization of B. cinerea populations to tomato and grapevine hosts but not to other tested plants. Population genetic analysis revealed two pathogen clusters associated with tomato and grapevine, while the other clusters co-occurred on hydrangea, strawberry and bramble. Measurements of quantitative pathogenicity were consistent with host specialization of populations found on tomato, and to a lesser extent, populations found on grapevine. Pathogen populations from hydrangea and strawberry appeared to be generalist, while populations from bramble may be weakly specialized. Our results suggest that the polyphagous B. cinerea is more accurately described as a collection of generalist and specialist individuals in populations. This work opens new perspectives for grey mold management, while suggesting spatial optimization of crop organization within agricultural landscapes.

scholarly journals Peroxisomes Implicated in the Biosynthesis of Siderophores and Biotin, Cell Wall Integrity, Autophagy, and Response to Hydrogen Peroxide in the Citrus Pathogenic Fungus Alternaria alternata

2021 ◽  
Vol 12 ◽  
Author(s):  
Pei-Ching Wu ◽  
Yu-Kun Chen ◽  
Jonar I. Yago ◽  
Kuang-Ren Chung
Keyword(s):  
Cell Wall ◽  
Alternaria Alternata ◽  
Plant Pathogens ◽  
Protein Import ◽  
Fluorescent Protein ◽  
Pathogenic Fungus ◽  
Cell Wall Integrity ◽  
Eosin Y ◽  
Peroxisomal Biogenesis ◽  
Fungal Plant Pathogens

Little is known about the roles of peroxisomes in the necrotrophic fungal plant pathogens. In the present study, a Pex6 gene encoding an ATPase-associated protein was characterized by analysis of functional mutations in the tangerine pathotype of Alternaria alternata, which produces a host-selective toxin. Peroxisomes were observed in fungal cells by expressing a mCherry fluorescent protein tagging with conserved tripeptides serine-lysing-leucine and transmission electron microscopy. The results indicated that Pex6 plays no roles in peroxisomal biogenesis but impacts protein import into peroxisomes. The number of peroxisomes was affected by nutritional conditions and H2O2, and their degradation was mediated by an autophagy-related machinery termed pexophagy. Pex6 was shown to be required for the formation of Woronin bodies, the biosynthesis of biotin, siderophores, and toxin, the uptake and accumulation of H2O2, growth, and virulence, as well as the Slt2 MAP kinase-mediated maintenance of cell wall integrity. Adding biotin, oleate, and iron in combination fully restored the growth of the pex6-deficient mutant (Δpex6), but failed to restore Δpex6 virulence to citrus. Adding purified toxin could only partially restore Δpex6 virulence even in the presence of biotin, oleate, and iron. Sensitivity assays revealed that Pex6 plays no roles in resistance to H2O2 and superoxide, but plays a negative role in resistance to 2-chloro-5-hydroxypyridine (a hydroxyl radical-generating compound), eosin Y and rose Bengal (singlet oxygen-generating compounds), and 2,3,5-triiodobenzoic acid (an auxin transport inhibitor). The diverse functions of Pex6 underscore the importance of peroxisomes in physiology, pathogenesis, and development in A. alternata.

scholarly journals Changes in Peptaibol Production of Trichoderma Species during In Vitro Antagonistic Interactions with Fungal Plant Pathogens

Biomolecules ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 730
Author(s):  
Parisa Rahimi Tamandegani ◽  
Tamás Marik ◽  
Doustmorad Zafari ◽  
Dóra Balázs ◽  
Csaba Vágvölgyi ◽  
...  
Keyword(s):  
High Performance ◽  
Plant Pathogens ◽  
Pathogenic Fungus ◽  
Alternaria Solani ◽  
Pathogenic Fungi ◽  
Isobutyric Acid ◽  
Reversed Phase ◽  
Trichoderma Species ◽  
Fungal Plant Pathogens

Trichoderma species are widely used as biofungicides for the control of fungal plant pathogens. Several studies have been performed to identify the main genes and compounds involved in Trichoderma–plant–microbial pathogen cross-talks. However, there is not much information about the exact mechanism of this profitable interaction. Peptaibols secreted mainly by Trichoderma species are linear, 5–20 amino acid residue long, non-ribosomally synthesized peptides rich in α-amino isobutyric acid, which seem to be effective in Trichoderma–plant pathogenic fungus interactions. In the present study, reversed phase (RP) high-performance liquid chromatography (HPLC) coupled with electrospray ionization (ESI) mass spectrometry (MS) was used to detect peptaibol profiles of Trichoderma strains during interactions with fungal plant pathogens. MS investigations of the crude extracts deriving from in vitro confrontations of Trichoderma asperellum and T. longibrachiatum with different plant pathogenic fungi (Fusarium moniliforme, F. culmorum, F. graminearum, F. oxysporum species complex, Alternaria solani and Rhizoctonia solani) were performed to get a better insight into the role of these non-ribosomal antimicrobial peptides. The results revealed an increase in the total amount of peptaibols produced during the interactions, as well as some differences in the peptaibol profiles between the confrontational and control tests. Detection of the expression level of the peptaibol synthetase tex1 by qRT-PCR showed a significant increase in T. asperellum/R. solani interaction in comparison to the control. In conclusion, the interaction with plant pathogens highly influenced the peptaibol production of the examined Trichoderma strains.

scholarly journals The potential of silver nanoparticles to control Rhizoctonia solani (AG3-PT) growth in vitro

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
HARTATI OKTARINA ◽  
JAMES WOODHALL ◽  
IAN SINGLETON
Keyword(s):  
Silver Nanoparticles ◽  
Rhizoctonia Solani ◽  
Plant Pathogens ◽  
Pathogenic Fungus ◽  
Subsequent Development ◽  
Hyphal Growth ◽  
Disease Symptoms ◽  
Fungal Plant Pathogens ◽  
Sclerotium Production

Silver nanoparticles (AgNPs) have known anti-microbial properties and therefore have the potential to be used to control fungal plant pathogens. In this study we investigated the growth of a plant pathogenic fungus, Rhizoctonia solani (AG3-PT) in the presence of AgNPs. The effect of AgNPs at two different levels (20 and 50 mg L-1) on hyphal growth and sclerotium production and viability in R. solani was investigated. The results showed that at 20 mg AgNPs L-1 R. solani hyphal growth was reduced along with the production of sclerotia. The results indicate that AgNPs have the potential to control R. solani growth and subsequent development of plant disease symptoms.

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