scholarly journals Tissue Dependence and Differential Cordycepin Sensitivity of Race-Specific Resistance Responses in the Barley—Powdery Mildew Interaction

1997 ◽  
Vol 10 (7) ◽  
pp. 830-839 ◽  
Author(s):  
Ruth Schiffer ◽  
Regina Görg ◽  
Birgit Jarosch ◽  
Uli Beckhove ◽  
Gregor Bahrenberg ◽  
...  
Keyword(s):  
Cell Death ◽  
Powdery Mildew ◽  
Host Cell ◽  
Specific Resistance ◽  
Leaf Tissue ◽  
Primary Leaf ◽  
Hypersensitive Cell Death ◽  
Fungal Development ◽  
Interaction Sites ◽  
Host Cell Death

Epidermal cell monolayers prepared from partially dissected barley (Hordeum vulgare) coleoptiles were used for in vivo analysis of race-specific resistance to powdery mildew (Erysiphe graminis f. sp. hordei) specified by host genes Mla-1, Mla-12, and Mlg. Complete resistance governed by each of these genes is closely associated with hypersensitive cell death (hypersensitive response, HR) in primary leaf tissue. In contrast, Mla-12 coleoptile tissue reveals a fully compatible, Mla-1 coleoptile tissue a partially compatible, and Mlg coleoptile tissue an incompatible interaction upon challenge with pathogen races carrying corresponding avirulence functions. Quantitative recording of single plant-fungus interaction sites showed arrest of fungal development in papillae on Mlg coleoptiles. On Mla-1 and Mla-12 coleoptiles, attacked cells become predominantly penetrated by the fungus. Approximately one third of penetrated cells on Mla-1 coleoptiles subsequently undergo an HR. These sites reveal no further fungal development. Both Mlg and Mla-12 coleoptiles fail to mount an HR. The effect of cordycepin (3′-deoxyadenosine), an inhibitor of mRNA synthesis, was studied in planta on primary leaf tissue of Mla-12 and Mlg genotypes. Host cell death triggered by either gene is reduced to background levels observed in the near-isogenic compatible interaction and exhibits the same dose-dependent cordycepin sensitivity. Inhibition of Mlg-triggered, single-cell HR is not accompanied by release of fungal growth arrest, indicating cordycepin insensitivity of a papillae-associated resistance component. The data suggest that host cell death is a requisite component for expression of Mla-type but not Mlg-type resistance.

scholarly journals Tissue-Specific Superoxide Generation at Interaction Sites in Resistant and Susceptible Near-Isogenic Barley Lines Attacked by the Powdery Mildew Fungus (Erysiphe graminis f. sp. hordei)

1998 ◽  
Vol 11 (4) ◽  
pp. 292-300 ◽  
Author(s):  
Ralph Hückelhoven ◽  
Karl-Heinz Kogel
Keyword(s):  
Cell Death ◽  
Powdery Mildew ◽  
Mesophyll Cell ◽  
Epidermal Cells ◽  
Erysiphe Graminis ◽  
Time Range ◽  
Powdery Mildew Fungus ◽  
Hypersensitive Cell Death ◽  
Interaction Sites ◽  
Nbt Reduction

The pathogenesis-related, azide-insensitive generation of superoxide anions (O2 -) was comparatively analyzed in near-isogenic barley (Hordeum vulgare cv. Pallas) lines carrying the powdery mildew (Erysiphe graminis f. sp. hordei) resistance genes Mla12, Mlg, and mlo5, respectively, by the microscopic detection of nitroblue tetra-zolium (NBT) reduction to dark blue formazan dyes. These genes govern fungal arrest at different stages of the interaction: (i) at the penetration stage within cell wall appositions (papillae) leaving the attacked cell alive (mlo); (ii) within papillae of cells that subsequently undergo a hypersensitive cell death (HR) (Mlg); or (iii) after penetration by a subsequent HR (Mla12). The susceptible parent line Pallas showed a transient O2 - generation in penetrated epidermal cells at 18 h after inoculation (hai), whereas epidermal cells of the resistant BCPMla12 produced O2 - over a longer time range (by 18 to 36 hai) preceding cell death. No oxidative burst was detected in association with penetration resistance due to effective papillae (BCPMlg and BCPmlo5) although Mlg specified an HR subsequent to fungal arrest. Hence, O2 - generation in attacked epidermal cells was a result of fungal penetration of the host cell walls and subsequent contact with the host plasma membrane, and not a requirement for HR elicitation. O2 - generation in the mesophyll tissue beneath attacked cells was associated with the response mediated by the genes Mla12 and Mlg. However, only BCPMla12 showed mesophyll cell death. The data indicate that, in barley, O2 - accumulation is not a single key determinant of HR in response to a powdery mildew attack.

scholarly journals Broadly Conserved Fungal Effector BEC1019 Suppresses Host Cell Death and Enhances Pathogen Virulence in Powdery Mildew of Barley (Hordeum vulgare L.) (Retracted)

2015 ◽  
Vol 28 (9) ◽  
pp. 968-983 ◽  
Author(s):  
Ehren Whigham ◽  
Shan Qi ◽  
Divya Mistry ◽  
Priyanka Surana ◽  
Ruo Xu ◽  
...  
Keyword(s):  
Cell Death ◽  
Hordeum Vulgare ◽  
Powdery Mildew ◽  
Host Cell ◽  
Type Iii Secretion ◽  
Hordeum Vulgare L ◽  
Confounding Effect ◽  
Pathogen Virulence ◽  
Host Cell Death ◽  
Bacterial Type

The authors have retracted ‘Broadly Conserved Fungal Effector BEC1019 Suppresses Host Cell Death and Enhances Pathogen Virulence in Powdery Mildew of Barley (Hordeum vulgare L.)’ by Ehren Whigham, Shan Qi, Divya Mistry, Priyanka Surana, Ruo Xu, Gregory Fuerst, Clara Pliego, Laurence V. Bindschedler, Pietro D. Spanu, Julie A. Dickerson, Roger W. Innes, Dan Nettleton, Adam J. Bogdanove, and Roger P. Wise published in Mol. Plant-Microbe Interact. Vol. 28, pages 968–983, doi: 10.1094/MPMI-02-15-0027-FI. In a re-examination of some of the results of the bacterial type III secretion–based assays, the authors discovered a confounding effect of the titer of the bacterium used that had not been controlled for, rendering some of the experimental results presented in the paper inconclusive. For details, please see their letter to the editor [Carter et al. 2018]. This article was retracted on 24 May 2018.

scholarly journals Pathogen induced subversion of NAD+ metabolism mediating host cell death: a target for development of chemotherapeutics

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Ayushi Chaurasiya ◽  
Swati Garg ◽  
Ashish Khanna ◽  
Chintam Narayana ◽  
Ved Prakash Dwivedi ◽  
...  
Keyword(s):  
Cell Death ◽  
Host Cell ◽  
Nicotinamide Adenine Dinucleotide ◽  
Malaria Parasite ◽  
Host Cells ◽  
Nicotinamide Adenine ◽  
Targeted Therapeutics ◽  
Nad Metabolism ◽  
Host Cell Death ◽  
Nanomolar Range

AbstractHijacking of host metabolic status by a pathogen for its regulated dissemination from the host is prerequisite for the propagation of infection. M. tuberculosis secretes an NAD+-glycohydrolase, TNT, to induce host necroptosis by hydrolyzing Nicotinamide adenine dinucleotide (NAD+). Herein, we expressed TNT in macrophages and erythrocytes; the host cells for M. tuberculosis and the malaria parasite respectively, and found that it reduced the NAD+ levels and thereby induced necroptosis and eryptosis resulting in premature dissemination of pathogen. Targeting TNT in M. tuberculosis or induced eryptosis in malaria parasite interferes with pathogen dissemination and reduction in the propagation of infection. Building upon our discovery that inhibition of pathogen-mediated host NAD+ modulation is a way forward for regulation of infection, we synthesized and screened some novel compounds that showed inhibition of NAD+-glycohydrolase activity and pathogen infection in the nanomolar range. Overall this study highlights the fundamental importance of pathogen-mediated modulation of host NAD+ homeostasis for its infection propagation and novel inhibitors as leads for host-targeted therapeutics.

scholarly journals TolC-Dependent Modulation of Host Cell Death by the Francisella tularensis Live Vaccine Strain

2014 ◽  
Vol 82 (5) ◽  
pp. 2068-2078 ◽  
Author(s):  
Christopher R. Doyle ◽  
Ji-An Pan ◽  
Patricio Mena ◽  
Wei-Xing Zong ◽  
David G. Thanassi
Keyword(s):  
Cell Death ◽  
Immune Responses ◽  
Host Cell ◽  
Francisella Tularensis ◽  
Vaccine Strain ◽  
Live Vaccine ◽  
Live Vaccine Strain ◽  
Type I ◽  
Content Type ◽  
Host Cell Death

ABSTRACTFrancisella tularensisis a facultative intracellular, Gram-negative pathogen and the causative agent of tularemia. We previously identified TolC as a virulence factor of theF. tularensislive vaccine strain (LVS) and demonstrated that a ΔtolCmutant exhibits increased cytotoxicity toward host cells and elicits increased proinflammatory responses compared to those of the wild-type (WT) strain. TolC is the outer membrane channel component used by the type I secretion pathway to export toxins and other bacterial virulence factors. Here, we show that the LVS delays activation of the intrinsic apoptotic pathway in a TolC-dependent manner, both during infection of primary macrophages and during organ colonization in mice. The TolC-dependent delay in host cell death is required forF. tularensisto preserve its intracellular replicative niche. We demonstrate that TolC-mediated inhibition of apoptosis is an active process and not due to defects in the structural integrity of the ΔtolCmutant. These findings support a model wherein the immunomodulatory capacity ofF. tularensisrelies, at least in part, on TolC-secreted effectors. Finally, mice vaccinated with the ΔtolCLVS are protected from lethal challenge and clear challenge doses faster than WT-vaccinated mice, demonstrating that the altered host responses to primary infection with the ΔtolCmutant led to altered adaptive immune responses. Taken together, our data demonstrate that TolC is required for temporal modulation of host cell death during infection byF. tularensisand highlight how shifts in the magnitude and timing of host innate immune responses may lead to dramatic changes in the outcome of infection.

Fusarium graminearum produces different xylanases causing host cell death that is prevented by the xylanase inhibitors XIP-I and TAXI-III in wheat

Plant Science ◽  
2015 ◽  
Vol 240 ◽  
pp. 161-169 ◽  
Author(s):  
Silvio Tundo ◽  
Ilaria Moscetti ◽  
Franco Faoro ◽  
Mickaël Lafond ◽  
Thierry Giardina ◽  
...  
Keyword(s):  
Cell Death ◽  
Host Cell ◽  
Fusarium Graminearum ◽  
Host Cell Death

scholarly journals Pattern Recognition Receptors and the Host Cell Death Molecular Machinery

2018 ◽  
Vol 9 ◽  
Author(s):  
Gustavo P. Amarante-Mendes ◽  
Sandy Adjemian ◽  
Laura Migliari Branco ◽  
Larissa C. Zanetti ◽  
Ricardo Weinlich ◽  
...  
Keyword(s):  
Pattern Recognition ◽  
Cell Death ◽  
Host Cell ◽  
Pattern Recognition Receptors ◽  
Host Cell Death ◽  
Molecular Machinery
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