Extracellular proteolytic cascade in tomato activates immune protease Rcr3

Proteolytic cascades regulate immunity and development in animals, but these cascades in plants have not yet been reported. Here we report that the extracellular immune protease Rcr3 of tomato is activated by P69B and other subtilases (SBTs), revealing a proteolytic cascade regulating extracellular immunity in solanaceous plants. Rcr3 is a secreted papain-like Cys protease (PLCP) of tomato that acts both in basal resistance against late blight disease (Phytophthora infestans) and in gene-for-gene resistance against the fungal pathogenCladosporium fulvum (syn.Passalora fulva). Despite the prevalent model that Rcr3-like proteases can activate themselves at low pH, we found that catalytically inactive proRcr3 mutant precursors are still processed into mature mRcr3 isoforms. ProRcr3 is processed by secreted P69B and other Asp-selective SBTs in solanaceous plants, providing robust immunity through SBT redundancy. The apoplastic effector EPI1 ofP. infestanscan block Rcr3 activation by inhibiting SBTs, suggesting that this effector promotes virulence indirectly by preventing the activation of Rcr3(-like) immune proteases. Rcr3 activation inNicotiana benthamianarequires a SBT from a different subfamily, indicating that extracellular proteolytic cascades have evolved convergently in solanaceous plants or are very ancient in the plant kingdom. The frequent incidence of Asp residues in the cleavage region of Rcr3-like proteases in solanaceous plants indicates that activation of immune proteases by SBTs is a general mechanism, illuminating a proteolytic cascade that provides robust apoplastic immunity.

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Evaluation of bio-agents and neem based products against late blight disease (Phytophthora infestans) of potato

Indian Phytopathology ◽

10.1007/s42360-021-00330-6 ◽

2021 ◽

Vol 74 (1) ◽

pp. 181-187

Author(s):

Mehi Lal ◽

Sorabh Chaudhary ◽

Sanjay Rawal ◽

Sanjeev Sharma ◽

Manoj Kumar ◽

...

Keyword(s):

Late Blight ◽

Phytophthora Infestans ◽

Late Blight Disease ◽

Blight Disease

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Two new defensive constituents from potato tubers (Solanum tuberosum)

Zeitschrift für Naturforschung B ◽

10.1515/znb-2016-0234 ◽

2017 ◽

Vol 72 (6) ◽

pp. 393-396

Author(s):

Liangyan Liu ◽

Jun Han ◽

Yong Shen

Keyword(s):

Solanum Tuberosum ◽

Late Blight ◽

Quantum Chemical ◽

Spectroscopic Analysis ◽

2D Nmr ◽

Moderate Activity ◽

Potato Tubers ◽

Mycelia Growth ◽

Late Blight Disease ◽

Blight Disease

AbstractTwo new defensive constituents, solatuberenol A (1) and 3-O-β-d-glucopyranosyl stigmasta-5(6),24(28)-diene (2), were isolated from the potato tubers (Solanum tuberosum) infected with late blight disease. Their structures were identified by extensive spectroscopic analysis, including HRMS, IR, UV, 1D/2D NMR, ECD and quantum chemical calculations. Compounds 1 and 2 showed moderate activity against Phytophthora infestans with mycelia-growth inhibition of 30.1% and 52.4%, respectively, at the concentration of 500 ppm.

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CfT-I: an LTR-retrotransposon in Cladosporium fulvum, a fungal pathogen of tomato

MGG Molecular & General Genetics ◽

10.1007/bf00265429 ◽

1992 ◽

Vol 233 (3) ◽

pp. 337-347 ◽

Cited By ~ 58

Author(s):

Mark T. McHale ◽

Ian N. Roberts ◽

Stuart M. Noble ◽

Christine Beaumont ◽

Michael P. Whitehead ◽

...

Keyword(s):

Fungal Pathogen ◽

Ltr Retrotransposon ◽

Cladosporium Fulvum

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Phenotypic Characterization of Recent Clonal Lineages of Phytophthora infestans in the United States

Plant Disease ◽

10.1094/pdis-07-12-0682-re ◽

2013 ◽

Vol 97 (7) ◽

pp. 873-881 ◽

Cited By ~ 48

Author(s):

G. Danies ◽

I. M. Small ◽

K. Myers ◽

R. Childers ◽

W. E. Fry

Keyword(s):

United States ◽

Late Blight ◽

Phytophthora Infestans ◽

The United States ◽

Phenotypic Characterization ◽

Phenotypic Traits ◽

Mating Types ◽

Late Blight Disease ◽

Blight Disease

Phytophthora infestans, the causal agent of late blight disease, has been reported in the United States and Canada since the mid-nineteenth century. Due to the lack of or very limited sexual reproduction, the populations of P. infestans in the United States are primarily reproducing asexually and, thus, show a simple genetic structure. The emergence of new clonal lineages of P. infestans (US-22, US-23, and US-24) responsible for the late blight epidemics in the northeastern region of the United States in the summers of 2009 and 2010 stimulated an investigation into phenotypic traits associated with these genotypes. Mating type, differences in sensitivity to mefenoxam, differences in pathogenicity on potato and tomato, and differences in rate of germination were studied for clonal lineages US-8, US-22, US-23, and US-24. Both A1 and A2 mating types were detected. Lineages US-22, US-23, and US-24 were generally sensitive to mefenoxam while US-8 was resistant. US-8 and US-24 were primarily pathogenic on potato while US-22 and US-23 were pathogenic on both potato and tomato. Indirect germination was favored at lower temperatures (5 and 10°C) whereas direct germination, though uncommon, was favored at higher temperatures (20 and 25°C). Sporangia of US-24 released zoospores more rapidly than did sporangia of US-22 and US-23. The association of characteristic phenotypic traits with genotype enables the prediction of phenotypic traits from rapid genotypic analyses for improved disease management.

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The Assessment of Potato Late Blight Disease in Western Amhara Region, Ethiopia

SSRN Electronic Journal ◽

10.2139/ssrn.3882375 ◽

2021 ◽

Author(s):

Gebremariam Asaye Emrie ◽

Merkuz Abera Admassu ◽

Adane Tesfaye Lema

Keyword(s):

Late Blight ◽

Potato Late Blight ◽

Amhara Region ◽

Late Blight Disease ◽

Blight Disease

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Activation of the Promoter of the Tnt1 Retrotransposon in Tomato After Inoculation with the Fungal Pathogen Cladosporium fulvum

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.1999.12.7.592 ◽

1999 ◽

Vol 12 (7) ◽

pp. 592-603 ◽

Cited By ~ 18

Author(s):

Corinne Mhiri ◽

Pierre J. G. M. De Wit ◽

Marie-Angèle Grandbastien

Keyword(s):

Transcriptional Activation ◽

Fungal Pathogen ◽

Defense Responses ◽

Stress Factors ◽

Cladosporium Fulvum ◽

Biotic And Abiotic Stress ◽

Abiotic Stress Factors ◽

Biological Responses ◽

Leaf Tissues ◽

Specific Factors

The copia-like Tnt1 element of tobacco is one of the few active plant retrotransposons and is transcriptionally activated, in tobacco and in heterologous species, by biotic and abiotic stress factors. In order to establish more precisely the link between Tnt1 activation and plant defense responses, the expression of the Tnt1 promoter was studied in a gene-for-gene pathosystem, the interaction between tomato and the fungal pathogen Cladosporium fulvum. In compatible interactions, Tnt1 expression is highly induced throughout the leaf regions colonized by the fungus, while in incompatible interactions Tnt1 induction is transient and localized in distinct foci. Tnt1 expression after fungal inoculation parallels the differential activation of tomato defense genes. Tnt1 expression is induced by nonspecific factors of plant or fungal origin present in apoplastic fluids of leaf tissues infected by virulent races of C. fulvum, but is also activated by specific factors resulting from the interaction between fungal avirulence peptides and plant resistance genes. Tnt1 activation by apoplastic fluids containing avirulence peptides of C. fulvum is detected soon after elicitation. These results demonstrate that Tnt1 transcriptional activation correlates with biological responses of tomato to infection by C. fulvum and is mediated through signals originating from both race-specific and non-race-specific perception pathways.

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Fungicidal management of Alternaria alternata (Fr.) Keissler causing blight of gerbera (Gerbera jamesonii H. Bolus ex J.D. Hook)

Journal of Applied and Natural Science ◽

10.31018/jans.v4i2.253 ◽

2012 ◽

Vol 4 (2) ◽

pp. 220-227 ◽

Cited By ~ 6

Author(s):

Dipak T. Nagrale ◽

Anil P. Gaikwad ◽

Sanjay Goswami ◽

Lalan Sharma

Keyword(s):

Disease Management ◽

Disease Control ◽

Alternaria Alternata ◽

Fungal Pathogen ◽

Management Practices ◽

Bordeaux Mixture ◽

Gerbera Jamesonii ◽

Leaf Spots ◽

Aerial Parts ◽

Blight Disease

Alternaria, the fungal pathogen has wide host range generally attacks the aerial parts of plants causing leaf spots and blights. Gerbera is a genus of ornamental flower plants. Gerbera plants are infected by many diseases. Different disease management practices are adopted in gerbera cultivation. The fungicidal management of Alternaria blight is one of the important strategies for the disease management in gerbera in polyhouse condition. In this study, preventive and curative fungicidal sprays were adopted for the management of blight disease in polyhouse. This study revealed that preventive fungicidal sprays were significant over curative fungicidal sprays for the management of Alternaria alternata blight of gerbera (Gerbera jamesonii H. Bolus ex J.D. Hook) in polyhouse. The preventive sprays made of Bordeaux mixture (0.6 %), tricyclazole (0.1%) and iprodione + carbendazim (0.1%) fungicides were found effective with 95.85 %, 96.59 % and 95.88 % disease control respectively, under polyhouse condition.

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Filament formation by metabolic enzymes is a specific adaptation to an advanced state of cellular starvation

10.1101/003277 ◽

2014 ◽

Cited By ~ 2

Author(s):

Ivana Petrovska ◽

Elisabeth Nüske ◽

Matthias C Munder ◽

Gayathrie Kulasegaran ◽

Liliana Malinovska ◽

...

Keyword(s):

Metabolic Enzymes ◽

Low Ph ◽

General Mechanism ◽

Filament Formation ◽

Ph Change ◽

Cooperative Process ◽

A Cell ◽

Enzymatic Inactivation ◽

Physical Organization

One of the key questions in biology is how the metabolism of a cell responds to changes in the environment. In budding yeast, starvation causes a drop in intracellular pH, but the functional role of this pH change is not well understood. Here, we show that the enzyme glutamine synthetase (Gln1) forms filaments at low pH and that filament formation leads to enzymatic inactivation. Filament formation by Gln1 is a highly cooperative process, strongly dependent on macromolecular crowding, and involves back-to-back stacking of cylindrical homo-decamers into filaments that associate laterally to form higher order fibrils. Other metabolic enzymes also assemble into filaments at low pH. Hence, we propose that filament formation is a general mechanism to inactivate and store key metabolic enzymes during a state of advanced cellular starvation. These findings have broad implications for understanding the interplay between nutritional stress, the metabolism and the physical organization of a cell.

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Plant pathogen effector utilizes host susceptibility factor NRL1 to degrade the immune regulator SWAP70

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1808585115 ◽

2018 ◽

Vol 115 (33) ◽

pp. E7834-E7843 ◽

Cited By ~ 20

Author(s):

Qin He ◽

Shaista Naqvi ◽

Hazel McLellan ◽

Petra C. Boevink ◽

Nicolas Champouret ◽

...

Keyword(s):

Late Blight ◽

Plant Pathogens ◽

Dominant Negative ◽

Host Protein ◽

Host Susceptibility ◽

Dominant Negative Mutant ◽

Virus Induced Gene Silencing ◽

Pathogen Effector ◽

Late Blight Disease ◽

Blight Disease

Plant pathogens deliver effectors into plant cells to suppress immunity. Whereas many effectors inactivate positive immune regulators, other effectors associate with negative regulators of immunity: so-called susceptibility (S) factors. Little is known about how pathogens exploit S factors to suppress immunity. Phytophthora infestans RXLR effector Pi02860 interacts with host protein NRL1, which is an S factor whose activity suppresses INF1-triggered cell death (ICD) and is required for late blight disease. We show that NRL1 interacts in yeast and in planta with a guanine nucleotide exchange factor called SWAP70. SWAP70 associates with endosomes and is a positive regulator of immunity. Virus-induced gene silencing of SWAP70 in Nicotiana benthamiana enhances P. infestans colonization and compromises ICD. In contrast, transient overexpression of SWAP70 reduces P. infestans infection and accelerates ICD. Expression of Pi02860 and NRL1, singly or in combination, results in proteasome-mediated degradation of SWAP70. Degradation of SWAP70 is prevented by silencing NRL1, or by mutation of Pi02860 to abolish its interaction with NRL1. NRL1 is a BTB-domain protein predicted to form the substrate adaptor component of a CULLIN3 ubiquitin E3 ligase. A dimerization-deficient mutant, NRL1NQ, fails to interact with SWAP70 but maintains its interaction with Pi02860. NRL1NQ acts as a dominant-negative mutant, preventing SWAP70 degradation in the presence of effector Pi02860, and reducing P. infestans infection. Critically, Pi02860 enhances the association between NRL1 and SWAP70 to promote proteasome-mediated degradation of the latter and, thus, suppress immunity. Preventing degradation of SWAP70 represents a strategy to combat late blight disease.

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