scholarly journals Syringolin Reprograms Wheat to Undergo Hypersensitive Cell Death in a Compatible Interaction with Powdery Mildew

2001 ◽  
Vol 13 (1) ◽  
pp. 153-161 ◽  
Author(s):  
Urs Wäspi ◽  
Patrick Schweizer ◽  
Robert Dudler
Keyword(s):  
Cell Death ◽  
Powdery Mildew ◽  
Compatible Interaction ◽  
Hypersensitive Cell Death

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 ShNPSN11, a vesicle-transport-related gene, confers disease resistance in tomato to Oidium neolycopersici

2020 ◽  
Vol 477 (19) ◽  
pp. 3851-3866
Author(s):  
Qinggui Lian ◽  
Yanan Meng ◽  
Xinbei Zhao ◽  
Yuanliu Xu ◽  
Yang Wang ◽  
...  
Keyword(s):  
Cell Death ◽  
Powdery Mildew ◽  
Cell Biology ◽  
Induced Defense ◽  
Vesicle Transport ◽  
Pcr Analysis ◽  
Oidium Neolycopersici ◽  
Mrna Accumulation ◽  
Hypersensitive Cell Death ◽  
Defense Signaling

Tomato powdery mildew, caused by Oidium neolycopersici, is a fungal disease that results in severe yield loss in infected plants. Herein, we describe the function of a class of proteins, soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs), which play a role in vesicle transport during defense signaling. To date, there have been no reports describing the function of tomato SNAREs during resistance signaling to powdery mildew. Using a combination of classical plant pathology-, genetics-, and cell biology-based approaches, we evaluate the role of ShNPSN11 in resistance to the powdery mildew pathogen O. neolycopersici. Quantitative RT-PCR analysis of tomato SNAREs revealed that ShNPSN11 mRNA accumulation in disease-resistant varieties was significantly increased following pathogen, compared with susceptible varieties, suggesting a role during induced defense signaling. Using in planta subcellular localization, we demonstrate that ShNPSN11 was primarily localized at the plasma membrane, consistent with the localization of SNARE proteins and their role in defense signaling and trafficking. Silencing of ShNPSN11 resulted in increased susceptibility to O. neolycopersici, with pathogen-induced levels of H2O2 and cell death elicitation in ShNPSN11-silenced lines showing a marked reduction. Transient expression of ShNPSN11 did not result in the induction of a hypersensitive cell death response or suppress cell death induced by BAX. Taken together, these data demonstrate that ShNPSNl11 plays an important role in defense activation and host resistance to O. neolycopersici in tomato LA1777.

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