scholarly journals Multiple knockout mutants reveal a high redundancy of phytotoxic compounds that determine necrotrophic pathogenesis of Botrytis cinerea

2021 ◽  
Author(s):  
Thomas Leisen ◽  
Janina Werner ◽  
Patrick Pattar ◽  
Edita Ymeri ◽  
Frederik Sommer ◽  
...  
Keyword(s):  
Cell Death ◽  
Botrytis Cinerea ◽  
Plant Cell ◽  
Fungal Pathogen ◽  
Host Plants ◽  
Host Cells ◽  
Necrotic Tissue ◽  
Knockout Mutants ◽  
Marker Free ◽  
First Time

Botrytis cinerea is a major pathogen of more than 1400 plant species. During infection, the kills host cells during infection and spreads through necrotic tissue, which is believed to be supported by induction of programmed plant cell death. To comprehensively evaluate the contributions of most of the currently known plant cell death inducing proteins (CDIPs) and metabolites for necrotrophic infection, an optimized CRISPR/Cas protocol was established which allowed serial marker-free mutagenesis to generate Botrytis mutants lacking up to 12 different CDIPs. Infection analysis revealed a decrease in virulence with increasing numbers of knockouts, and differences in the effects of knockouts on different host plants. The on planta secretomes obtained from these mutants revealed substantial remaining necrotic activity after infiltration into leaves. Our study has addressed for the first time the functional redundancy of virulence factors of a fungal pathogen, and demonstrates that B. cinerea releases a highly redundant cocktail of proteins and metabolites to achieve necrotrophic infection of a wide variety of host plants.

scholarly journals Quantitative interactions drive Botrytis cinerea disease outcome across the plant kingdom

2018 ◽  
Author(s):  
Celine Caseys ◽  
Gongjun Shi ◽  
Nicole Soltis ◽  
Raoni Gwinner ◽  
Jason Corwin ◽  
...  
Keyword(s):  
Botrytis Cinerea ◽  
Host Species ◽  
Fungal Pathogen ◽  
Host Plants ◽  
Quantitative Resistance ◽  
Quantitative Model ◽  
Plant Kingdom ◽  
Host Diversity ◽  
Evolutionary Relatedness ◽  
Pathogen Strains

AbstractBotrytis cinerea is a polyphagous fungal pathogen that causes necrotic disease on more than a thousand known hosts widely spread across the plant kingdom. While it is known that quantitative resistance in the host and quantitative virulence in the pathogen largely mediate this pathosystem, how this pathogen interacts with the extensive host diversity is unknown. Does this pathogen have quantitative virulence efficiency on all hosts or individual solutions for each host? To address this question, we generated an infectivity matrix of 98 strains of Botrytis cinerea on 90 genotypes representing eight host plants. This experimental infectivity matrix showed that the predominant sources of quantitative variation are between host species and among pathogen strains. Furthermore, the eight eudicot hosts interacted individually with Botrytis cinerea strains independently of the evolutionary relatedness between hosts. An additive quantitative model can explain the complexity of these interactions in which Botrytis host specificity and general virulence have distinct polygenic architectures.

scholarly journals The secreted hypersensitive response inducing protein 1 fromBotrytis cinereadisplays non-canonical PAMP-activity

2020 ◽  
Author(s):  
Tanja Jeblick ◽  
Thomas Leisen ◽  
Christina E. Steidele ◽  
Jonas Müller ◽  
Florian Mahler ◽  
...  
Keyword(s):  
Cell Death ◽  
Plant Cell ◽  
Hypersensitive Response ◽  
Plant Pathogens ◽  
Infection Process ◽  
Host Cells ◽  
Plant Responses ◽  
Cell Wall Degrading Enzymes ◽  
Molecular Pattern ◽  
Biotrophic Pathogens

AbstractAccording to their lifestyle, plant pathogens are divided into biotrophic and necrotrophic organisms. While biotrophic pathogens establish a relationship with living host cells, necrotrophic pathogens rapidly kill host cells and feed on the cell debris. To this end, the necrotrophic ascomycete fungusBotrytis cinereasecretes large amounts of phytotoxic proteins and cell wall degrading enzymes. However, the precise role of these proteins during the infection process is unknown. Here we report on the identification and characterization of the previously unknown toxic protein hypersensitive response inducing protein 1 (Hip1), which induces plant cell death. We found the adoption of a folded protein structure to be a prerequisite for Hip1 to exert its necrosis-inducing activity inNicotiana benthamiana. Localization and the induction of specific plant responses by Hip1 indicate recognition as pathogen-associated molecular pattern at the plant plasma membrane. Our results demonstrate that recognition of Hip1, even in the absence of obvious enzymatic or poreforming activity, induces strong plant defense reactions eventually leading to plant cell death.

scholarly journals Botrytis cinerea BcPTP1 is a late infection phase, cysteine rich protein cytotoxic effector

2021 ◽  
Author(s):  
Wenjun Zhu ◽  
Mengxue Yu ◽  
Ran Xu ◽  
Kai Bi ◽  
Chao Xiong ◽  
...  
Keyword(s):  
Cell Death ◽  
Botrytis Cinerea ◽  
Point Mutations ◽  
Host Cells ◽  
Broad Host Range ◽  
Late Infection ◽  
Toxic Activity ◽  
Cysteine Rich Protein ◽  
Phytotoxic Effect ◽  
Infection Stage

Botrytis cinerea is a broad-host-range necrotrophic phytopathogen responsible for serious crops diseases. To facilitate infection, B. cinerea secretes a large number of effectors that induce plant cell death. In screening secretome data of B. cinerea during infection stage, we identified a phytotoxic protein (BcPTP1) that can also induce immune resistance in plants. BcPTP1 is a small (90 aa), cysteine rich protein without any known domains. Transiently expression of BcPTP1 in leaves caused chlorosis that intensifies with time and eventually lead to cell death. Point mutations in eight of the 10 cysteine residues of BcPTP1 abolished the toxic effect, however residual toxic activity remained after heating the peptide, suggesting contribution of unknown epitopes to protein phytotoxic effect. The transcript level of the bcptp1 gene was low during the first 36 h after inoculation and increased sharply upon transition to the late infection stage, suggesting a role of BcPTP1 in lesion spreading. While statistically insignificant, deletion of the bcptp1 gene led to slightly smaller lesions on bean leaves. Further analyses indicated that BcPTP1 is internalized into plant cells after secreting into the apoplast and its phytotoxic effect is negatively regulated by the receptor-like kinases BAK1 and SOBIR1. Collectively, our findings show that BcPTP1 is a virulence factor that toxifies the host cells and facilitates lesion spreading during the late infection stage.

scholarly journals Biology of Maize Kernel Infection by Fusarium verticillioides

2010 ◽  
Vol 23 (1) ◽  
pp. 6-16 ◽  
Author(s):  
Keith E. Duncan ◽  
Richard J. Howard
Keyword(s):  
Fungal Pathogen ◽  
Fluorescent Protein ◽  
Fusarium Verticillioides ◽  
Passive Movement ◽  
Host Cells ◽  
Conidial Suspension ◽  
Symptom Development ◽  
Kernel Infection ◽  
Rot Disease ◽  
First Time

Fusarium kernel rot disease starburst symptomatology was characterized fully for the first time. Two maize lines were hand pollinated and inoculated, using a fluorescent protein-expressing transformant of the fungal pathogen Fusarium verticillioides, by introduction of a conidial suspension through the silk channel of intact ears. Microscopy was used to identify the infection court and document initial stages of kernel colonization and subsequent manifestation of macroscopic symptoms. The fungus entered kernels of susceptible line AD38 via an open stylar canal and spread extracellularly and over the kernel through the nucellus region, sporadically entering pericarp and filling the long thick-walled mesocarp cells. Hyphae spread within pericarp from cell to cell via pits, colonizing files of host cells by growing both up and down the kernel in a radial pattern that preceded macroscopic symptom development. The starburst symptom developed subsequently, and mirrored colonization exactly, when there was extensive dissolution of the thick walls of pericarp cells. Line HT1 exhibited a closed stylar canal phenotype and was not susceptible—except when the pericarp surface was breached mechanically. We hypothesize the passive movement of conidia along the surface of silks, perhaps via capillarity, as a possible mechanism for pathogen access to the infection court.

scholarly journals The Botrytis cinerea Crh1 transglycosylase is a cytoplasmic effector triggering plant cell death and defense response

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kai Bi ◽  
Loredana Scalschi ◽  
Namrata Jaiswal ◽  
Tesfaye Mengiste ◽  
Renana Fried ◽  
...  
Keyword(s):  
Cell Death ◽  
Botrytis Cinerea ◽  
Plant Cell ◽  
Defense Responses ◽  
Phytopathogenic Fungus ◽  
Necrotrophic Pathogen ◽  
Fungal Cell ◽  
Protein Uptake ◽  
Transglycosylation Activity ◽  
Plant Infection

AbstractCrh proteins catalyze crosslinking of chitin and glucan polymers in fungal cell walls. Here, we show that the BcCrh1 protein from the phytopathogenic fungus Botrytis cinerea acts as a cytoplasmic effector and elicitor of plant defense. BcCrh1 is localized in vacuoles and the endoplasmic reticulum during saprophytic growth. However, upon plant infection, the protein accumulates in infection cushions; it is then secreted to the apoplast and translocated into plant cells, where it induces cell death and defense responses. Two regions of 53 and 35 amino acids are sufficient for protein uptake and cell death induction, respectively. BcCrh1 mutant variants that are unable to dimerize lack transglycosylation activity, but are still able to induce plant cell death. Furthermore, Arabidopsis lines expressing the bccrh1 gene exhibit reduced sensitivity to B. cinerea, suggesting a potential use of the BcCrh1 protein in plant immunization against this necrotrophic pathogen.

scholarly journals Characterization of Virulence Function of Pseudomonas cichorii Avirulence Protein E1 (AvrE1) during Host Plant Infection

2021 ◽  
Vol 37 (5) ◽  
pp. 494-501
Author(s):  
Duyen Do Tran Huong ◽  
Nagendran Rajalingam ◽  
Yong Hoon Lee
Keyword(s):  
Cell Death ◽  
Disease Severity ◽  
Pseudomonas Syringae ◽  
Defense Mechanisms ◽  
Host Plants ◽  
Early Infection ◽  
Host Cells ◽  
Deficient Mutant ◽  
Pseudomonas Cichorii ◽  
Plant Infection

<i>Pseudomonas cichorii</i> secretes effectors that suppress defense mechanisms in host plants. However, the function of these effectors, including avirulence protein E1 (AvrE1), in the pathogenicity of <i>P. cichorii</i>, remains unexplored. In this study, to investigate the function of <i>avrE1</i> in <i>P. cichorii</i> JBC1 (PcJBC1), we created an <i>avrE1</i>-deficient mutant (JBC1<sup>ΔavrE1</sup>) using CRISPR/Cas9. The disease severity caused by JBC1<sup>ΔavrE1</sup> in tomato plants significantly decreased by reducing water soaking during early infection stage, as evidenced by the electrolyte leakage in infected leaves. The disease symptoms caused by JBC1<sup>ΔavrE1</sup> in the cabbage midrib were light-brown spots compared to the dark-colored ones caused by PcJBC1, which indicates the role of AvrE1 in cell lysis. The <i>avrE1</i>-deficient mutant failed to elicit cell death in non-host tobacco plants. Disease severity and cell death caused by JBC1<sup>ΔavrE1</sup> in host and non-host plants were restored through heterologous complementation with <i>avrE1</i> from <i>Pseudomonas syringae</i> pv. <i>tomato</i> DC3000 (PstDC3000). Overall, our results indicate that <i>avrE1</i> contributes to cell death during early infection, which consequently increases disease development in host plants. The roles of PcJBC1 AvrE1 in host cells remain to be elucidated.

scholarly journals An Elicitor from Botrytis cinerea Induces the Hypersensitive Response in Arabidopsis thaliana and Other Plants and Promotes the Gray Mold Disease

2006 ◽  
Vol 96 (3) ◽  
pp. 299-307 ◽  
Author(s):  
Eri M. Govrin ◽  
Shimon Rachmilevitch ◽  
Budhi Sagar Tiwari ◽  
Mazal Solomon ◽  
Alex Levine
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Death ◽  
Botrytis Cinerea ◽  
Hypersensitive Response ◽  
Specific Inhibitor ◽  
Gray Mold ◽  
Host Cells ◽  
Host Responses ◽  
Pr Genes ◽  
Intercellular Fluid

Botrytis cinerea is a necrotrophic fungus that infects over 200 plant species. Previous studies showed that host cells collapse in advance of the hyphae, suggesting secretion of toxins or elicitors. We have partially characterized elicitor activity from intercellular fluid extracted from Arabidopsis thaliana leaves infected with B. cinerea. Treatment of intact leaves or cell cultures with either intercellular fluid from infected leaves or medium from inoculated A. thaliana cell culture induced generation of reactive oxygen species, resulting in reduced photosynthesis, electrolyte leakage, and necrotic lesions that resembled the hypersensitive response (HR). The necrosis was inhibited by diphenyleneiodonium, a specific inhibitor of NADPH oxidase, and by chelating free iron, suggesting the involvement of hydroxyl radicals. The necrosis was also suppressed in dnd1 mutants that are compromised in HR. In contrast, increased cell death was observed in acd2 mutants, indicating the involvement of the host defense signaling pathways. Treatment with the intercellular fluid from infected leaves also induced transcription of pathogenesis-related (PR) genes, such as PR-1, PR-5, HSR203J, and of senescence-associated gene SAG-13. Moreover, rapid transcription of the ethylene-dependent AtEBP gene was detected, indicating induction of ethylene production. The inter-cellular fluid from infected A. thaliana induced cell death in other plants, in line with the lack of B. cinerea specificity. In summary, the intercellular fluid mimicked a range of molecular and physiological host responses that are observed during infection with a live fungus. Moreover, it accelerated the B. cinerea infection, suggesting that the elicitor may act as a pathogenicity factor in the progression of gray mold disease.

Toxoplasma Gondii Bradyzoites Elicit Transcriptional Changes in Host Cells to Prevent IFNγ-Mediated Cell Death

2019 ◽  
Author(s):  
Simona Seizova ◽  
Alexandra L Garnham ◽  
Michael J Coffey ◽  
Lachlan W Whitehead ◽  
Kelly L Rogers ◽  
...  
Keyword(s):  
Cell Death ◽  
Toxoplasma Gondii ◽  
Host Cells ◽  
Transcriptional Changes

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.

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