Histological comparison of Cladosporium fulvum race 1 on immune, resistant, and susceptible tomato varieties

1976 ◽  
Vol 54 (3-4) ◽  
pp. 224-234 ◽  
Author(s):  
George Lazarovits ◽  
Verna J. Higgins
Keyword(s):  
Cell Damage ◽  
Starch Content ◽  
Leaf Tissue ◽  
Aerial Mycelium ◽  
Host Cells ◽  
Cladosporium Fulvum ◽  
Lesion Area ◽  
Race 1 ◽  
Histochemical Tests ◽  
Susceptible Tomato

Histological comparisons were carried out on three varieties of tomato, Potentate (Cf0), V-121 (Cf3), and Vinequeen (Cf2, Cf4), inoculated with race 1 of Cladosporium fulvum. Examination of leaves harvested at regular intervals indicated that under optimal conditions for disease development, spore germination and penetration were similar on the leaves of the three varieties. The susceptible Potentate became extensively colonized by intercellular mycelium, but relatively little visible damage occurred in the affected cells until sporulation was abundant. In V-121, resistance was expressed by slightly slower growth of the mycelium in the leaf tissue, but colonization was still extensive. Host cell damage became prominent just before the formation of aerial mycelium. Cells in the lesion area on V-121 became necrotic or showed various changes, including reduced starch content in the chloroplasts and the association of extracellular material with the cell walls. Histochemical tests indicated that polyphenols were present in the lesions. The mycelia in V-121 became highly vacuolated and sporulation was absent or greatly reduced. In the highly resistant (immune) Vinequeen variety, fungal development was restricted to a few cells in the mesophyll region. Host cells adjacent to and some distance from the fungus showed extensive deposition of material that was at least partly composed of callose.

STUDIES ON THE PARASITISM OF CLADOSPORIUM FULVUM

1967 ◽  
Vol 45 (11) ◽  
pp. 2125-2135
Author(s):  
Thomas Curren
Keyword(s):  
Nitrogen Nutrition ◽  
Chromatographic Study ◽  
Cladosporium Fulvum ◽  
Tomato Plants ◽  
Carbon And Nitrogen ◽  
Amino Compounds ◽  
Race 1 ◽  
Partial Deficiency ◽  
Susceptible Tomato ◽  
Reduced Light

A study was made of the carbon and nitrogen nutrition of races 7, 8, and 10 of Cladosporium fulvum, and an attempt was made to relate the findings to the differential pathogenicity of the races.Cysteine was found to exert a differential effect on the growth of two races of the pathogen. Race 1 was stimulated by concentrations inhibitory to race 6. C. fulvum was found to have a partial deficiency for thiamine. The sporulation of race 10 on susceptible tomato plants was heavier with alanine-grown cultures than with any other nutritional treatment. Altering the nitrogen nutrition of varieties Potentate (S) and V-121 (R) did not affect their differential reactions to race 1. A reduction in nitrogen feeding to Stirling Castle (R) increased its resistance to race 1.A chromatographic study was made of the changes in amino compounds and sugars in Potentate and V-121 after infection by races 1 and 6. The relation of the findings to the resistance of V-121 to race 1 is discussed.The resistance of Stirling Castle was investigated by comparing the amino compounds and sugars in leaves of healthy plants and plants infected by race 1 under optimal conditions and under reduced light, where the resistance breaks down. Chromatographic analyses showed a noticeable depletion of certain metabolites in plants infected under reduced light as compared with the amount of depletion, if any, in the controls.

The Role of Purinergic Signaling in Trichomonas vaginalis Infection

2020 ◽  
Vol 20 ◽  
Author(s):  
Micheli Ferla ◽  
Tiana Tasca
Keyword(s):  
Drug Targets ◽  
Trichomonas Vaginalis ◽  
Hiv Transmission ◽  
Cell Damage ◽  
Purinergic Signaling ◽  
Host Cells ◽  
Purine Nucleotides ◽  
Cellular Effects ◽  
Adverse Pregnancy ◽  
Purine Salvage Pathways

: Trichomoniasis, one of the most common non-viral sexually transmitted infections worldwide, is caused by the parasite Trichomonas vaginalis. The pathogen colonizes the human urogenital tract and the infection is associated with complications such as adverse pregnancy outcomes, cervical cancer, and an increase in HIV transmission. The mecha-nisms of pathogenicity are multifactorial, and controlling immune responses is essential for infection maintenance. Extra-cellular purine nucleotides are released by cells in physiological and pathological conditions, and they are hydrolyzed by enzymes called ecto-nucleotidases. The cellular effects of nucleotides and nucleosides occur via binding to purinoceptors, or throughthe uptake by nucleoside transporters. Altogether, enzymes, receptors and transporters constitute the purinergic signaling, a cellular network that regulates several effects in practically all systems including mammals, helminths, proto-zoa, bacteria, and fungi. In this context, this review updates the data on purinergic signaling involved in T. vaginalis biol-ogy and interaction with host cells, focusing on the characterization of ecto-nucleotidases and on purine salvage pathways. The implications of the final products, the nucleosides adenosine and guanosine, for human neutrophil response and vagi-nal epithelial cell damage reveal the purinergic signaling as a potential new mechanism for alternative drug targets.

EFFECTS OF NITROGEN, PHOSPHORUS, POTASSIUM, AND MANURE FACTORIALLY APPLIED TO POTATOES IN A LONG-TERM STUDY

1973 ◽  
Vol 53 (2) ◽  
pp. 205-211 ◽  
Author(s):  
W. N. BLACK ◽  
R. P. WHITE
Keyword(s):  
Solanum Tuberosum L ◽  
Starch Content ◽  
Leaf Tissue ◽  
Soil Test ◽  
Term Study ◽  
Long Term Study ◽  
Soil Test P ◽  
Yield Responses ◽  
Nitrogen Phosphorus

The effects of N, P, K, and manure factorially applied to potato (Solanum tuberosum L.) yields, starch content, and soil and tissue nutrient levels were evaluated on continuous plots over 12 yr in a 4-yr potato, grain, hay, hay rotation. Although yield responses were observed with N, P, and K applications, manure application substantially increased yields above yield levels due to applied N, P, and K. Increasing rates of KCl strongly depressed tuber starch contents. Soil test P and K levels increased with repeated fertility applications, and leaf tissue levels were increased with N, P, and K treatments.

Scanning electron microscopy of Fusarium oxysporum f.sp. lycopersici in xylem vessels of wilt-resistant and susceptible tomato plants

1980 ◽  
Vol 58 (22) ◽  
pp. 2360-2366 ◽  
Author(s):  
Erik L. Stromberg ◽  
Malcolm E. Corden
Keyword(s):  
Electron Microscopy ◽  
Hyphal Growth ◽  
Susceptible Host ◽  
Vessel Elements ◽  
Host Pathogen ◽  
Race 1 ◽  
Perforation Plates ◽  
Susceptible Tomato ◽  
Scanning Electron ◽  
Pathogen Combinations

Vessels in stems of 'Jefferson' (race 1 resistant and race 2 susceptible) and 'Bonny Best' (race 1 and 2 susceptible) tomato cultivars inoculated with Fusarium oxysporum f.sp. lycopersici race 1 or 2 were examined by scanning electron microscopy. Four days after inoculation of Jefferson with conidia of race 1, the inoculum conidia and resultant hyphae generally were collapsed, whereas in the susceptible host–pathogen combinations the inoculum conidia and hyphae appeared normal. Neither the plants of the resistant nor the susceptible host-pathogen combinations had perforation plates or tyloses within vessel elements capable of trapping conidia or effectively blocking hyphal growth. The perforation plates of all vessel elements are reduced to slightly lipped rims and thus provide unrestricted apertures for hyphal growth and conidial movement in the transpiration stream. In the susceptible host–pathogen combinations, mycelial growth often filled the vessels, but no sporulation was noted. Frequent lateral spread of the pathogen occurred between adjacent vessels through the bordered pit-pairs. Infrequent occurrence of tyloses and a lack of occlusions by tyloses in the resistant host–pathogen combination suggest that vascular wilt resistance within the stem is not due primarily to physical containment of the pathogen in the vessels. Collapsed conidia and hyphae in the resistant host–pathogen combination suggests that fungitoxic materials in the vessels suppress the pathogen and contribute to resistance.

Association of epidermal lignification with nonhost resistance of cucurbits to fungi

1985 ◽  
Vol 63 (12) ◽  
pp. 2393-2398 ◽  
Author(s):  
Raymond Hammerschmidt ◽  
Alice M. Bonnen ◽  
Gary C. Bergstrom ◽  
Karen K. Baker
Keyword(s):  
Epidermal Cell ◽  
Cell Walls ◽  
Cupric Oxide ◽  
Histochemical Staining ◽  
The Other ◽  
Host Cells ◽  
Nonhost Resistance ◽  
Resistance Response ◽  
Etiolated Seedlings ◽  
Race 1

Etiolated seedlings of cucumber, muskmelon, watermelon, pumpkin, and squash were inoculated with Colletotrichum lagenarium (Pass.) Ell. & Halst. race 1, Colletotrichum atramentarium (Berk. & Br.) Taub., or Helminthosporium carbonum Ull. The fungi germinated and produced appressoria equally well on all hosts. Penetrations into host cells, however, were routinely observed only in the interactions of C. lagenarium with cucumber, muskmelon, and watermelon. Histochemical staining of the other host–pathogen interactions (nonhost interactions) revealed that the lack of penetration by fungi into nonhost tissue was associated with the deposition of lignin in the upper and lateral host epidermal cell walls around appressoria. Treatment of the lignified tissues with 0.5 M NaOH or hot ethanol did not alter staining reactions. Treatment with hot aminoethanol, a delignifying agent, did eliminate stainings. Cupric oxide oxidation of lignified epidermal cell walls from each host revealed that each host produced a p-coumaryl-rich, guaiacyl-poor ligninlike material. These results suggest that lignification may be a general nonhost resistance response in the Cucurbitaceae.

scholarly journals Biological and Molecular Characterization of Fusarium oxysporum f. sp. lycopersici Divides Race 1 Isolates into Separate Virulence Groups

1999 ◽  
Vol 89 (2) ◽  
pp. 156-160 ◽  
Author(s):  
Jurriaan J. Mes ◽  
Emma A. Weststeijn ◽  
Frits Herlaar ◽  
Joep J. M. Lambalk ◽  
Jelle Wijbrandi ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Random Amplified Polymorphic Dna ◽  
Vegetative Compatibility ◽  
Avirulence Gene ◽  
Resistance Response ◽  
Vegetative Compatibility Groups ◽  
Small Set ◽  
Race 1 ◽  
Race 2 ◽  
Susceptible Tomato

A collection of race 1 and race 2 isolates of Fusarium oxysporum f. sp. lycopersici was screened for vegetative compatibility and characterized by random amplified polymorphic DNA (RAPD) analysis to establish the identity and genetic diversity of the isolates. Comparison of RAPD profiles revealed two main groups that coincide with vegetative compatibility groups (VCGs). In addition, several single-member VCGs were identified that could not be grouped in one of the two main RAPD clusters. This suggests that F. oxysporum f. sp. lycopersici is a polyphyletic taxon. To assign avirulence genotypes to race 1 isolates, they were tested for their virulence on a small set of tomato lines (Lycopersicon esculentum), including line OT364. This line was selected because it shows resistance to race 2 isolates but, unlike most other race 2-resistant lines, susceptibility to race 1 isolates. To exclude the influence of other components than those related to the race-specific resistance response, we tested the virulence of race 1 isolates on a susceptible tomato that has become race 2 resistant by introduction of an I-2 transgene. The results show that both line OT364 and the transgenic line were significantly affected by four race 1 isolates, but not by seven other race 1 isolates nor by any race 2 isolates. This allowed a subdivision of race 1 isolates based on the presence or absence of an avirulence gene corresponding to the I-2 resistance gene. The data presented here support a gene-for-gene relationship for the interaction between F. oxysporum f. sp. lycopersici and its host tomato.

FURTHER STUDIES ON THE PHYSIOLOGY OF CLADOSPORIUM FULVUM CKE. AND RESISTANCE IN TOMATO

1964 ◽  
Vol 42 (10) ◽  
pp. 1365-1386 ◽  
Author(s):  
Ruth L. Lowther
Keyword(s):  
Culture Media ◽  
Carbon Sources ◽  
Amino Nitrogen ◽  
Cladosporium Fulvum ◽  
Host Parasite Interactions ◽  
Race 1 ◽  
Species Characteristics ◽  
Pathogenic Races ◽  
Host Parasite

Some host–parasite interactions of the C. fulvum – tomato leaf complex have been correlated with degrees of utilization in vitro by races of the pathogen of metabolites which have been shown to occur in different amounts in some tomato hosts which react differentially to them. Similarities and differences in the behavior of three pathogenic races were noted when the plants were grown in a number of amino nitrogen and sugar carbon sources. Similarities are interpreted as representing species characteristics; on the other hand, differences, including colony colors in glutamine and γ-aminobutyric acid, appear to be racial characteristics. Further evidence suggesting that certain host metabolites modify or condition the pathogenic expression was obtained from studies of the effect on pathogenicity of culture media differing in amino nitrogen content. From a comparison of the metabolites of host–pathogen complexes of differing reaction types, some insight was gained into probable nutritional requirements for a race 1 susceptible response. Conversely, where these differed in other reaction-type complexes, clues were obtained regarding possible reasons for resistance to this race.

scholarly journals First Report of Fusarium oxysporum f. sp. lactucae Race 1 Causing Fusarium Wilt of Lettuce in Norway

Plant Disease ◽  
2021 ◽  
Author(s):  
Maria Luz Herrero ◽  
Nina Elisabeth Nagy ◽  
Halvor Solheim
Keyword(s):  
Costa Rica ◽  
Fusarium Oxysporum ◽  
Vascular Tissue ◽  
Uv Light ◽  
Elongation Factor ◽  
Aerial Mycelium ◽  
Light Cycle ◽  
Single Spore ◽  
Fungal Isolates ◽  
Race 1

Lettuce (Lactuca sativa L.) is produced in Norway both in field and greenhouses. In Norway, greenhouse lettuce is one of the most important vegetables grown year-round. In winter 2018, wilting symptoms were observed on soil-grown lettuce of the cultivar Frillice in a greenhouse in south east Norway (Buskerud county). Affected plants showed stunted growth, wilting of outer leaves, and brownish discoloration of vascular tissues of taproots and crowns. According to the producer, the disease led to an estimated 10% of yield losses. Fungal isolates were obtained from crowns and roots of diseased plants collected from the greenhouse in 2018 and 2019. Two single spore isolates, 231274 from 2018 and 231725 from 2019, were used in further studies. The isolates were incubated on synthetic nutrient-poor agar (SNA) at 18-20 ⁰C, and a 12 hours dark, 12 hours UV light cycle. Isolate 231274 produced abundant macro- and microconidia characteristics of Fusarium oxysporum while macroconidia were never observed in isolate 231725. On potato dextrose agar (PDA), colonies of isolate 231274 were purple in color and colonies of isolate 231725 were pinkish with abundant aerial mycelium. For PCR-assay, DNA from mycelia was extracted using Easy-DNA kit (Invitrogen). A portion of the translation elongation factor 1-α (EF1-α) gene was amplified using primers F-728F (Carbone and Kohn. 1999) and EF2 (O'Donnell et al. 1998) as described by Aas et al. 2018. Blast analysis of both sequences (accession no. MW316853 for 231274 and MW316854 for 231275) obtained a 99% homology with the sequence of Fusarium oxysporum f.sp. lactucae (FOL) race 1 strain S1 (accession no. DQ837657)(Mbofung et al. 2007). Both isolates were identified as race 1 by using specific primers Hani3’ and Hanilatt3rev (Pasquali et al. 2007) as described by Cabral et al. 2014. To complete Koch’s postulate, lettuce plants of the cultivar Frillice were used. Race identity was confirmed using the differential lettuce cultivars Costa Rica No.4 (resistant to FOL race 1), Banchu Red Fire (resistant to FOL races 2 and 4) and Romana Romabella (resistant to FOL races 1 and 2) (Gilardi et al. 2017) provided by the breeding company Rijk Zwaan (De Lier, The Netherlands). For inoculation, roots of six 2-weeks old seedlings per cultivar were dipped in a spore suspension (1 x 106 CFU/ml) for 1 min, while controls were dipped in distilled water. Seedlings were planted in 250 ml pots containing fertilized potting substrate, and were placed in a greenhouse with temperature ranging from 15 to 35 ⁰C and an average of 23 ⁰C. After 10 days reduced growth was observed in cultivars Frillice and Banchu Red Fire for both fungal isolates. After 25 days wilting was observed in both cultivars. Affected plants presented discoloration of vascular tissue. No difference in growth was observed between cultivars Romana Romabella and Costa Rica No. 4 and their respective controls. FOL was re-isolated from all inoculated cultivars but not from controls. The colony patterns of the recovered isolates were the same than those of the isolates used for inoculation. These results confirm that the isolate belongs to race 1. Greenhouse lettuce in Norway is mainly produced in hydroponics. FOL is here reported to cause damages in soil- grown lettuce. Nevertheless FOL in hydroponic systems has been reported in Japan (Fujinaga et al. 2003) and Thailand (Thongkamngam and Jaenaksorn 2017). Thus, the possibility of infections in hydroponics remain a big concern for lettuce production in Norway.

scholarly journals First Report of a Chaetomella sp. Causing a Leaf Spot on Sansevieria trifasciata in China

Plant Disease ◽  
2013 ◽  
Vol 97 (7) ◽  
pp. 992-992 ◽  
Author(s):  
Y. L. Li ◽  
Z. Zhou ◽  
W. Lu ◽  
J. R. Ye
Keyword(s):  
Leaf Spot ◽  
Disease Incidence ◽  
Morphological Characteristics ◽  
Leaf Tissue ◽  
Aerial Mycelium ◽  
Control Treatment ◽  
Distilled Water ◽  
First Report ◽  
Potted Plants ◽  
Fungal Isolates

Sansevieria trifasciata originates from tropical West Africa. It is widely planted as a potted ornamental in China for improving indoor air quality (1). In February 2011, leaves of S. trifasciata plants in an ornamental market of Anle, Luoyang City, China, were observed with sunken brown lesions up to 20 mm in diameter, and with black pycnidia present in the lesions. One hundred potted plants were examined, with disease incidence at 20%. The symptomatic leaves affected the ornamental value of the plants. A section of leaf tissue from the periphery of two lesions from a plant was cut into 1 cm2 pieces, soaked in 70% ethanol for 30 s, sterilized with 0.1% HgCl2 for 2 min, then washed five times in sterilized distilled water. The pieces were incubated at 28°C on potato dextrose agar (PDA). Colonies of two isolates were brown with submerged hyphae, and aerial mycelium was rare. Abundant and scattered pycnidia were reniform, dark brown, and 200 to 350 × 100 to 250 μm. There were two types of setae on the pycnidia: 1) dark brown setae with inward curved tops, and 2) straight, brown setae. Conidia were hyaline, unicellular, cylindrical, and 3.75 to 6.25 × 1.25 to 2.50 μm. Morphological characteristics suggested the two fungal isolates were a Chaetomella sp. To confirm pathogenicity, six mature leaves of a potted S. trifasciata plant were wounded with a sterile pin after wiping each leaf surface with 70% ethanol and washing each leaf with sterilized distilled water three times. A 0.5 cm mycelial disk cut from the margin of a 5-day-old colony on a PDA plate was placed on each pin-wounded leaf, ensuring that the mycelium was in contact with the wound. Non-colonized PDA discs were placed on pin-wounded leaves as the control treatment. Each of two fungal isolates was inoculated on two leaves, and the control treatment was done similarly on two leaves. The inoculated plant was placed in a growth chamber at 28°C with 80% relative humidity. After 7 days, inoculated leaves produced brown lesions with black pycnidia, but no symptoms developed on the control leaves. A Chaetomella sp. was reisolated from the lesions of inoculated leaves, but not from the control leaves. An additional two potted plants were inoculated using the same methods as replications of the experiment, with identical results. To confirm the fungal identification, the internal transcribed spacer (ITS) region of rDNA of the two isolates was amplified using primers ITS1 and ITS4 (2) and sequenced. The sequences were identical (GenBank Accession No. KC515097) and exhibited 99% nucleotide identity to the ITS sequence of an isolate of Chaetomella sp. in GenBank (AJ301961). To our knowledge, this is the first report of a leaf spot of S. trifasciata caused by Chaetomella sp. in China as well as anywhere in the world. References: (1) X. Z. Guo et al. Subtropical Crops Commun. Zhejiang 27:9, 2005. (2) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, CA, 1990.

scholarly journals Complement-mediated tumor cell damage induced by antibodies against membrane cofactor protein (MCP, CD46).

1990 ◽  
Vol 172 (6) ◽  
pp. 1673-1680 ◽  
Author(s):  
T Seya ◽  
T Hara ◽  
M Matsumoto ◽  
Y Sugita ◽  
H Akedo
Keyword(s):  
Monoclonal Antibodies ◽  
T Cell ◽  
Cell Lines ◽  
Cell Damage ◽  
Human Cells ◽  
Host Cells ◽  
Membrane Cofactor Protein ◽  
Minimal Cell ◽  
Human T Cell ◽  
T Cell Lines

We have developed polyclonal and monoclonal antibodies against human membrane cofactor protein (MCP) to use as tools to investigate the functions of MCP on intact nucleated cells. Two human T cell lines, CEM and TALL, are CR1- and DAF-. Pretreatment of these cell lines with M177 and polyclonal anti-MCP, which inhibit cofactor activity almost completely, resulted in effective C3 deposition immediately following addition of these cells to Mg2+/EGTA/human sera. The deposited C3 remained expressed partly on the cell surface and most of them were gradually converted to C3bi. Some of the deposited C3 were complexed with membrane proteins, since 140- and 250-kD bands became significantly accumulated on SDS-PAGE by treatment with the antibodies. We next tested whether these C3-coated cells were damaged by complement-mediated cytolysis. p18, an inhibitor of membrane attack complex (MAC) formation, was negative in TALL but positive in CEM. TALL was lysed efficiently only by treatment with the polyclonal anti-MCP, while CEM showed only slight lysis with the same treatment. Monoclonal antibodies to MCP, including M177, caused only minimal cell destruction. Based on these results, together with the fact that decay-accelerating factor (DAF) serves as a factor for preventing C3 attack on human cells, we conclude that MCP and DAF cooperatively protect host cells from C3 targeting and, in these T cell lines, MCP is sufficient for preventing C3 deposition even without DAF. After all, human cells undergo almost no autologous complement-mediated cytolysis if they express at least one of the functionally active inhibitors, MCP, DAF, or p18.

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