scholarly journals Screening for Alternaria brassicicola resistance in the Brassicaceae: Bio-assay optimization and confocal microscopy insights into the infection process

2015 ◽  
Author(s):  
Marzena Nowakowska ◽  
Małgorzata Wrzesińska ◽  
Piotr Kamiński ◽  
Marcin Nowicki ◽  
Małgorzata Lichocka ◽  
...  
Keyword(s):  
Confocal Microscopy ◽  
Incubation Temperature ◽  
Leaf Age ◽  
Genetic Resistance ◽  
Field Tests ◽  
Resistance Breeding ◽  
Infection Process ◽  
Host Cells ◽  
Alternaria Brassicicola ◽  
Assay Optimization

Heavy losses incited yearly by Alternaria brassicicola on the vegetable Brassicaceae – have prompted our search for sources of genetic resistance against the resultant disease, dark leaf spot. We optimized several parameters to test the performance of the plants under controlled conditions to this disease, including leaf age and position, inoculum concentration, and incubation temperature. Using these optimized conditions, we screened a collection of 38 Brassicaceae cultigens with two methods (detached leaf and seedlings). Our results show, that either method can be used for the A. brassicicola resistance breeding, while the plant’s genotype was crucial in determining its response to the pathogen. The bio-assays for Alternaria resistance were more effective than the field tests, and resulted in identification of two interspecific hybrids that might be used in breeding programs. Confocal microscopy analyses of the leaf samples provided novel insights into the pathogen mode of infection: Direct epidermal infection or stomatal attack were dependent on plants’ resistance against A. brassicicola. Further, the actin network of the host cells reorganized around the papillas deposited under the pathogen’s appressorium. Papilla composition is predicted to be important in determining the plant’s resistance.

scholarly journals Screening for Alternaria brassicicola resistance in the Brassicaceae: Bio-assay optimization and confocal microscopy insights into the infection process

2016 ◽  
Author(s):  
Marzena Nowakowska ◽  
Małgorzata Wrzesińska ◽  
Piotr Kamiński ◽  
Marcin Nowicki ◽  
Małgorzata Lichocka ◽  
...  
Keyword(s):  
Confocal Microscopy ◽  
Incubation Temperature ◽  
Leaf Age ◽  
Genetic Resistance ◽  
Field Tests ◽  
Resistance Breeding ◽  
Infection Process ◽  
Host Cells ◽  
Alternaria Brassicicola ◽  
Assay Optimization

Heavy losses incited yearly by Alternaria brassicicola on the vegetable Brassicaceae – have prompted our search for sources of genetic resistance against the pathogen and the resultant disease, dark leaf spot. We optimized several parameters to test the performance of the plants under controlled conditions to this disease, including leaf age and position, inoculum concentration, and incubation temperature. Using these optimized conditions, we screened a collection of 38 Brassicaceae cultigens with two methods (detached leaf and seedlings). Our results show, that either method can be used for the A. brassicicola resistance breeding, while the plant’s genotype was crucial in determining its response to the pathogen. The laboartory bio-assays for A. brassicicola resistance were run under more stringent conditions than the field tests, and resulted in identification of two interspecific hybrids that might be used in breeding programs. Confocal microscopy analyses of the leaf samples provided data into the pathogen mode of infection: Direct epidermal infection or stomatal attack were related to plants’ resistance against A. brassicicola among the cultigens tested. Further, the actin network of the host cells reorganized around the papillas deposited under the pathogen’s appressorium.

scholarly journals Screening for Alternaria brassicicola resistance in the Brassicaceae: Bio-assay optimization and confocal microscopy insights into the infection process

2016 ◽  
Author(s):  
Marzena Nowakowska ◽  
Małgorzata Wrzesińska ◽  
Piotr Kamiński ◽  
Marcin Nowicki ◽  
Małgorzata Lichocka ◽  
...  
Keyword(s):  
Confocal Microscopy ◽  
Incubation Temperature ◽  
Leaf Age ◽  
Genetic Resistance ◽  
Field Tests ◽  
Resistance Breeding ◽  
Infection Process ◽  
Host Cells ◽  
Alternaria Brassicicola ◽  
Assay Optimization

Heavy losses incited yearly by Alternaria brassicicola on the vegetable Brassicaceae – have prompted our search for sources of genetic resistance against the pathogen and the resultant disease, dark leaf spot. We optimized several parameters to test the performance of the plants under controlled conditions to this disease, including leaf age and position, inoculum concentration, and incubation temperature. Using these optimized conditions, we screened a collection of 38 Brassicaceae cultigens with two methods (detached leaf and seedlings). Our results show, that either method can be used for the A. brassicicola resistance breeding, while the plant’s genotype was crucial in determining its response to the pathogen. The laboartory bio-assays for A. brassicicola resistance were run under more stringent conditions than the field tests, and resulted in identification of two interspecific hybrids that might be used in breeding programs. Confocal microscopy analyses of the leaf samples provided data into the pathogen mode of infection: Direct epidermal infection or stomatal attack were related to plants’ resistance against A. brassicicola among the cultigens tested. Further, the actin network of the host cells reorganized around the papillas deposited under the pathogen’s appressorium.

scholarly journals Greenhouse, Detached-leaf, and Field Testing Methods to Determine Cucumber Resistance to Gummy Stem Blight

1995 ◽  
Vol 120 (4) ◽  
pp. 673-680 ◽  
Author(s):  
Paul C. St. Amand ◽  
Todd C. Wehner
Keyword(s):  
Screening Method ◽  
Leaf Age ◽  
Free Water ◽  
Field Tests ◽  
Infection Process ◽  
Didymella Bryoniae ◽  
Stem Blight ◽  
Gummy Stem Blight ◽  
Detached Leaf ◽  
Highly Correlated

The effects of leaf age, guttation, stomata and hydathode characteristics, and wounding on the symptom development of gummy stem blight [Didymella bryoniae (Auersw.) Rehm] of cucumber (Cucumis sativus L.) were studied to develop a useful germplasm screening method. Older cucumber leaves were more susceptible than younger leaves in field, greenhouse, and detached-leaf tests. Compared to seedlings with true leaves, seedlings at the cotyledon stage were less susceptible, had a smaller variance for ratings, and were more likely to escape infection. Stomata density and hydathode counts were not correlated with field ratings; but, stomata length on older leaves was highly correlated with susceptibility y. In greenhouse and field tests, susceptibility y increased as guttation increased and actively guttating plants were more susceptible than nonguttating plants. Phylloplane moisture and/or nutrition were more important in the infection process than was stomata] opening. Although important, guttation was not necessary for infection. Dawn inoculation of field or greenhouse tests increased leaf symptoms compared with dusk inoculation. The increase was likely due to the free water and nutrients provided by guttation. Genotype ranks and ratings for detached-leaf tests were not correlated with field results. A useful method, highly correlated (r = 0.82 to 0.96) with field ratings. for screening germplasm in the greenhouse was developed.

scholarly journals A leaf disc assay for determining resistance of taro to Phytophthora colocasiae

2015 ◽  
Vol 68 ◽  
pp. 415-419
Author(s):  
J.L. Tyson ◽  
R.A. Fullerton
Keyword(s):  
Incubation Temperature ◽  
Leaf Age ◽  
Leaf Disc ◽  
Resistance Breeding ◽  
Leaf Blight ◽  
Phytophthora Colocasiae ◽  
Food Shortages ◽  
Taro Leaf Blight ◽  
Leaf Disc Assay ◽  
Disc Assay

Phytophthora colocasiae is a destructive fungal pathogen of taro (Colocasia esculenta) which causes taro leaf blight This disease destroyed Samoas taro export industry and led to local food shortages following introduction of the pathogen in 1993 In support of a Pacific regional taro resistance breeding programme laboratory studies in New Zealand aimed to develop a leaf disc bioassay for identifying taro genotypes with disease tolerance A medium has been developed that will retard senescence of the leaf discs for over 14 days The rate of leaf disc infection and subsequent lesion development varied with incubation temperature leaf age and taro cultivar An understanding of these factors and the variation they cause has resulted in a laboratory leaf disc assay for testing resistance of different taro cultivars to taro leaf blight

scholarly journals Identification of Lettuce (Lactuca sativa L.) Germplasm with Genetic Resistance to Drop Caused by Sclerotinia minor

2004 ◽  
Vol 129 (1) ◽  
pp. 70-76 ◽  
Author(s):  
Rebecca Grube ◽  
Edward Ryder
Keyword(s):  
Partial Resistance ◽  
Disease Incidence ◽  
Genetic Resistance ◽  
Geographic Origin ◽  
Field Tests ◽  
Field Performance ◽  
Resistance Breeding ◽  
Plant Introduction ◽  
Sclerotinia Minor ◽  
Naturally Occurring

Incidence of the disease lettuce drop caused by Sclerotinia minor is often high in California lettuce fields despite the use of cultural and chemical controls. Development of resistant lettuce cultivars has been hindered by the difficulty of evaluating resistance in field tests and the lack of a screening procedure that reliably predicts field performance. Several lettuce genotypes of diverse geographic origin and plant architecture including modern and heirloom cultivars, plant introduction accessions, and breeding lines, were evaluated for resistance to S. minor using several methods. Resistance was evaluated in fields that contained naturally occurring S. minor, in a field that contained both naturally occurring and manually incorporated S. minor inoculum, and in the greenhouse using two types of inocula. Many genotypes exhibited partial resistance to S. minor, with significantly reduced disease incidence relative to susceptible controls. The similarity of disease ratings observed in replicated field tests supports the conclusion that partial resistance is under genetic control. Ratings obtained in some greenhouse tests were highly correlated with field ratings, but this was not true for all tests. Therefore, although greenhouse evaluation with adequate replication and repetition can be used as a selection tool, field testing remains an essential component of S. minor resistance breeding programs.

Research Advances in Potyviruses: From the Laboratory Bench to the Field

2021 ◽  
Vol 59 (1) ◽  
Author(s):  
Xiuling Yang ◽  
Yinzi Li ◽  
Aiming Wang
Keyword(s):  
Control Strategies ◽  
Genetic Resistance ◽  
Plant Viruses ◽  
Infection Process ◽  
Future Research ◽  
Annual Review ◽  
Publication Date ◽  
Viral Pathogens ◽  
Genome Expression ◽  
Amount Of Knowledge

Potyviruses (viruses in the genus Potyvirus, family Potyviridae) constitute the largest group of known plant-infecting RNA viruses and include many agriculturally important viruses that cause devastating epidemics and significant yield losses in many crops worldwide. Several potyviruses are recognized as the most economically important viral pathogens. Therefore, potyviruses are more studied than other groups of plant viruses. In the past decade, a large amount of knowledge has been generated to better understand potyviruses and their infection process. In this review, we list the top 10 economically important potyviruses and present a brief profile of each. We highlight recent exciting findings on the novel genome expression strategy and the biological functions of potyviral proteins and discuss recent advances in molecular plant–potyvirus interactions, particularly regarding the coevolutionary arms race. Finally, we summarize current disease control strategies, with a focus on biotechnology-based genetic resistance, and point out future research directions. Expected final online publication date for the Annual Review of Phytopathology, Volume 59 is August 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

The illustrated life cycle of Microbotryum on the host plant Silene latifolia

Botany ◽  
2010 ◽  
Vol 88 (10) ◽  
pp. 875-885 ◽  
Author(s):  
Angela Maria Schäfer ◽  
Martin Kemler ◽  
Robert Bauer ◽  
Dominik Begerow
Keyword(s):  
Life Cycle ◽  
Light And Electron Microscopy ◽  
Laboratory Data ◽  
Infection Process ◽  
Host Cells ◽  
Silene Latifolia ◽  
Long Distance ◽  
Biological Studies ◽  
Plant Parasitic

The plant-parasitic genus Microbotryum (Pucciniomycotina) has been used as a model for various biological studies, but fundamental aspects of its life history have not been documented in detail. The smut fungus is characterized by a dimorphic life cycle with a haploid saprophytic yeast-like stage and a dikaryotic plant-parasitic stage, which bears the teliospores as dispersal agents. In this study, seedlings and flowers of Silene latifolia Poir. (Caryophyllaceae) were inoculated with teliospores or sporidial cells of Microbotryum lychnidis-dioicae (DC. ex Liro) G. Deml & Oberw. and the germination of teliospores, the infection process, and the proliferation in the host tissue were documented in vivo using light and electron microscopy. Although germination of the teliospore is crucial for the establishment of Microbotryum, basidium development is variable under natural conditions. In flowers, where the amount of nutrients is thought to be high, the fungus propagates as sporidia, and mating of compatible cells takes place only when flowers are withering and nutrients are decreasing. On cotyledons (i.e., nutrient-depleted conditions), conjugation occurs shortly after teliospore germination, often via intrapromycelial mating. After formation of an infectious hypha with an appressorium, the invasion of the host occurs by direct penetration of the epidermis. While the growth in the plant is typically intercellular, long distance proliferation seems mediated through xylem tracheary elements. At the beginning of the vegetation period, fungal cells were found between meristematic shoot host cells, indicating a dormant phase inside the plant. By using different microscopy techniques, many life stages of Microbotryum are illustrated for the first time, thereby allowing new interpretations of laboratory data.

scholarly journals An endometrial organoid model of Chlamydia-epithelial and immune cell interactions

2020 ◽  
Author(s):  
Lee Dolat ◽  
Raphael H. Valdivia
Keyword(s):  
Epithelial Cell ◽  
Cell Biology ◽  
Immune Cell ◽  
Three Dimensional ◽  
Time Lapse ◽  
Cell Types ◽  
Infection Process ◽  
Host Cells ◽  
Cell Diversity ◽  
Intracellular Organelles

ABSTRACTOur understanding of how the obligate intracellular bacterium Chlamydia trachomatis reprograms the cell biology of host cells in the upper genital tract is largely based on observations made in cell culture with transformed epithelial cell lines. Here we describe a primary spherical organoid system derived from endometrial tissue to recapitulate epithelial cell diversity, polarity, and ensuing responses to Chlamydia infection. Using high-resolution and time-lapse microscopy, we catalogue the infection process in organoids from invasion to egress, including the reorganization of the cytoskeleton and positioning of intracellular organelles. We show this model is amenable to screening C. trachomatis mutants for defects in the fusion of pathogenic vacuoles, the recruitment of intracellular organelles, and inhibition of cell death. Moreover, we reconstructed a primary immune cell response by co-culturing infected organoids with neutrophils, and determined that the effector TepP limits the recruitment of neutrophils to infected organoids. Collectively, our model details a system to study the cell biology of Chlamydia infections in three dimensional structures that better reflect the diversity of cell types and polarity encountered by Chlamydia upon infection of their animal hosts.Summary statement3D endometrial organoids to model Chlamydia infection and the role of secreted virulence factors in reprogramming host epithelial cells and immune cell recruitment

scholarly journals Labeling of Monilinia fructicola with GFP and Its Validation for Studies on Host-Pathogen Interactions in Stone and Pome Fruit

Genes ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1033
Author(s):  
Silvia Rodríguez-Pires ◽  
Eduardo Antonio Espeso ◽  
Nuria Baró-Montel ◽  
Rosario Torres ◽  
Paloma Melgarejo ◽  
...  
Keyword(s):  
Confocal Microscopy ◽  
Constitutive Expression ◽  
Infection Process ◽  
Monilinia Fructicola ◽  
Pome Fruit ◽  
Specific Primers ◽  
Genomic Location ◽  
Morphological Defects ◽  
Microscopy Analysis

To compare in vivo the infection process of Monilinia fructicola on nectarines and apples using confocal microscopy it is necessary to transform a pathogenic strain with a construct expressing a fluorescent chromophore such as GFP. Thus, germinated conidia of the pathogen were transformed with Agrobacterium tumefaciens carrying the plasmid pPK2-hphgfp that allowed the expression of a fluorescent Hph-GFP chimera. The transformants were selected according to their resistance to hygromycin B, provided by the constitutive expression of the hph-gfp gene driven by the glyceraldehyde 3P dehydrogenase promoter of Aspergillus nidulans. The presence of T-DNA construct in the genomic DNA was confirmed by PCR using a range of specific primers. Subsequent PCR-mediated analyses proved integration of the transgene at a different genomic location in each transformant and the existence of structural reorganizations at these insertion points. The expression of Hph-GFP in three independent M. fructicola transformants was monitored by immunodetection and epifluorescence and confocal microscopy. The Atd9-M. fructicola transformant displayed no morphological defects and showed growth and pathogenic characteristics similar to the wild type. Microscopy analysis of the Atd9 transformant evidenced that nectarine infection by M. fructicola was at least three times faster than on apples.

scholarly journals Targeting adhesion in fungal pathogen Candida albicans

2020 ◽  
Author(s):  
Harlei Martin ◽  
Kevin Kavanagh ◽  
Trinidad Velasco-Torrijos
Keyword(s):  
Candida Albicans ◽  
Fungal Infections ◽  
Initial Step ◽  
Infection Process ◽  
Host Cells ◽  
Fungal Cell ◽  
Receptor Interactions ◽  
Genes Encoding ◽  
Invasive Infections ◽  
Wall Components

Fungal infections with increasing resistance to conventional therapies are a growing concern. Candida albicans is a major opportunistic yeast responsible for mucosal and invasive infections. Targeting the initial step of the infection process (i.e., C. albicans adhesion to the host cell) is a promising strategy. A wide variety of molecules can interfere with adhesion processes via an assortment of mechanisms. Herein, we focus on how small molecules disrupt biosynthesis of fungal cell wall components and membrane structure, prevent the localization of GPI-anchor proteins, inhibit production of enzymes involved in adhesion, downregulate genes encoding adhesins and competitively inhibit receptor interactions. As a result, adhesion of C. albicans to host cells is reduced, paving the way to new classes of antifungal agents.

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