scholarly journals Conserved fungal effector suppresses PAMP-triggered immunity by targeting plant immune kinases

2018 ◽  
Vol 116 (2) ◽  
pp. 496-505 ◽  
Author(s):  
Hiroki Irieda ◽  
Yoshihiro Inoue ◽  
Masashi Mori ◽  
Kohji Yamada ◽  
Yuu Oshikawa ◽  
...  
Keyword(s):  
Oxidative Burst ◽  
Nicotiana Benthamiana ◽  
Host Plants ◽  
Plant Pathogens ◽  
Defense Responses ◽  
Pathogen Virulence ◽  
The Core ◽  
Bacterial Effectors ◽  
Multiple Pathogens ◽  
Core Effectors

Plant pathogens have optimized their own effector sets to adapt to their hosts. However, certain effectors, regarded as core effectors, are conserved among various pathogens, and may therefore play an important and common role in pathogen virulence. We report here that the widely distributed fungal effector NIS1 targets host immune components that transmit signaling from pattern recognition receptors (PRRs) in plants. NIS1 from two Colletotrichum spp. suppressed the hypersensitive response and oxidative burst, both of which are induced by pathogen-derived molecules, in Nicotiana benthamiana. Magnaporthe oryzae NIS1 also suppressed the two defense responses, although this pathogen likely acquired the NIS1 gene via horizontal transfer from Basidiomycota. Interestingly, the root endophyte Colletotrichum tofieldiae also possesses a NIS1 homolog that can suppress the oxidative burst in N. benthamiana. We show that NIS1 of multiple pathogens commonly interacts with the PRR-associated kinases BAK1 and BIK1, thereby inhibiting their kinase activities and the BIK1-NADPH oxidase interaction. Furthermore, mutations in the NIS1-targeting proteins, i.e., BAK1 and BIK1, in Arabidopsis thaliana also resulted in reduced immunity to Colletotrichum fungi. Finally, M. oryzae lacking NIS1 displayed significantly reduced virulence on rice and barley, its hosts. Our study therefore reveals that a broad range of filamentous fungi maintain and utilize the core effector NIS1 to establish infection in their host plants and perhaps also beneficial interactions, by targeting conserved and central PRR-associated kinases that are also known to be targeted by bacterial effectors.

scholarly journals Simple and efficient heterologous expression of necrosis-inducing effectors using the model plant Nicotiana benthamiana

2021 ◽  
Author(s):  
Bayantes Dagvadorj ◽  
Peter Solomon
Keyword(s):  
Heterologous Expression ◽  
High Throughput ◽  
Posttranslational Modifications ◽  
Nicotiana Benthamiana ◽  
Fungal Pathogens ◽  
Host Plants ◽  
Plant Pathogens ◽  
Expression Systems ◽  
In Planta ◽  
Model Plant

Plant fungal pathogens cause devastating diseases on cereal plants and threaten global food security. During infection, these pathogens secrete proteinaceous effectors that promote disease. Some of these effectors from necrotrophic plant pathogens induce a cell death response (necrosis), which facilitates pathogen growth in planta. Characterisation of these effectors typically requires heterologous expression and microbial expression systems such as bacteria and yeast are the predominantly used. However, microbial expression systems often require optimization for any given effector and are, in general, not suitable for effectors involving cysteine bridges and posttranslational modifications for activity. Here, we describe a simple and efficient method for expressing such effectors in the model plant Nicotiana benthamiana. Briefly, an effector protein is transiently expressed and secreted into the apoplast of N. benthamiana by Agrobacterium-mediated infiltration. Two-to-three days subsequent to agroinfiltration, the apoplast from the infiltrated leaves is extracted and can be directly used for phenotyping on host plants. The efficacy of this approach was demonstrated by expressing the ToxA, Tox3 and Tox1 necrosis-inducing effectors from Parastagonospora nodorum. All three effectors produced in N. benthamiana were capable of inducing necrosis in wheat lines, and two of three showed visible bands on Coomassie-stained gel. These data suggest that N. benthamiana-agroinfiltration system is a feasible tool to obtain fungal effectors, especially those that require disulfide bonds and posttranslational modifications. Furthermore, due to the low number of proteins typically observed in the apoplast (compared to intracellular), this simple and high-throughput approach circumvents the requirement to lyse cells and further purify the target proteins that is required in other heterologous systems. Because of its simplicity and potential for high-throughput, this method is highly amenable to the phenotyping of candidate protein effectors on host plants.

scholarly journals Bioactive Secondary Metabolites of the Genus Diaporthe and Anamorph Phomopsis from Terrestrial and Marine Habitats and Endophytes: 2010–2019

2021 ◽  
Vol 9 (2) ◽  
pp. 217
Author(s):  
Tang-Chang Xu ◽  
Yi-Han Lu ◽  
Jun-Fei Wang ◽  
Zhi-Qiang Song ◽  
Ya-Ge Hou ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Small Molecules ◽  
Host Plants ◽  
Plant Pathogens ◽  
Bioactive Metabolites ◽  
Drug Candidates ◽  
The Past ◽  
Marine Habitats ◽  
Bioactive Secondary Metabolites ◽  
Unidentified Species

The genus Diaporthe and its anamorph Phomopsis are distributed worldwide in many ecosystems. They are regarded as potential sources for producing diverse bioactive metabolites. Most species are attributed to plant pathogens, non-pathogenic endophytes, or saprobes in terrestrial host plants. They colonize in the early parasitic tissue of plants, provide a variety of nutrients in the cycle of parasitism and saprophytism, and participate in the basic metabolic process of plants. In the past ten years, many studies have been focused on the discovery of new species and biological secondary metabolites from this genus. In this review, we summarize a total of 335 bioactive secondary metabolites isolated from 26 known species and various unidentified species of Diaporthe and Phomopsis during 2010–2019. Overall, there are 106 bioactive compounds derived from Diaporthe and 246 from Phomopsis, while 17 compounds are found in both of them. They are classified into polyketides, terpenoids, steroids, macrolides, ten-membered lactones, alkaloids, flavonoids, and fatty acids. Polyketides constitute the main chemical population, accounting for 64%. Meanwhile, their bioactivities mainly involve cytotoxic, antifungal, antibacterial, antiviral, antioxidant, anti-inflammatory, anti-algae, phytotoxic, and enzyme inhibitory activities. Diaporthe and Phomopsis exhibit their potent talents in the discovery of small molecules for drug candidates.

scholarly journals Probability of infectious disease in humans during epidemic

2021 ◽  
Author(s):  
AM Karmishin ◽  
IV Borisevich ◽  
VI Skvortsova ◽  
AA Goryaev ◽  
SM Yudin
Keyword(s):  
Infectious Disease ◽  
Biological Object ◽  
Epidemiological Modeling ◽  
Pathogen Virulence ◽  
The Core ◽  
Special Cases ◽  
Quantitative Characteristics ◽  
Infective Dose ◽  
The Law ◽  
Generalized Time

Popular SIR models and their modifications used to generate predictions about epidemics and, specifically, the COVID-19 pandemic, are inadequate. The aim of this study was to find the laws describing the probability of infection in a biological object. Using theoretical methods of research based on the probability theory, we constructed the laws describing the probability of infection in a human depending on the infective dose and considering the temporal characteristics of a given infection. The so-called generalized time-factor law, which factors in the time of onset and the duration of an infectious disease, was found to be the most general. Among its special cases are the law describing the probability of infection developing by some point in time t, depending on the infective dose, and the law that does not factor in the time of onset. The study produced a full list of quantitative characteristics of pathogen virulence. The laws described in the study help to solve practical tasks and should lie at the core of mathematical epidemiological modeling.

scholarly journals Genetic Diversity of a Brazilian Strain Collection of Xanthomonas citri subsp. citri Based on the Type III Effector Protein Genes

Plant Disease ◽  
2012 ◽  
Vol 96 (2) ◽  
pp. 193-203 ◽  
Author(s):  
F. J. Jaciani ◽  
J. A. Ferro ◽  
M. I. T. Ferro ◽  
C. Vernière ◽  
O. Pruvost ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Plant Pathogens ◽  
Citrus Canker ◽  
Integrated Approach ◽  
Pcr Analysis ◽  
Type Iii Effector ◽  
Type Iii ◽  
Strain Collection ◽  
Bacterial Effectors ◽  
Dna Primers

Exclusion and eradication or management based on an integrated approach with less susceptible varieties, copper-based bactericides, and windbreaks are the two main strategies used to prevent or control citrus canker. Field tolerance or resistance to citrus canker is not found in the most important commercial sweet orange cultivars, and pathogen-derived resistance has been developed and applied in different crops to obtain resistant genotypes to plant pathogens. We describe the development of DNA primers and probes based on the type III effector genes avrXacE1, avrXacE2, avrXacE3, avrBs2, pthA4, hpaF, and XAC3090 (leucine rich protein), and their application in the evaluation of the genetic diversity of the pathogen. A total of 49 haplotypes were identified in 157 strains by Southern blot analysis. No genetic polymorphism was detected by BOX elements - and enterobacterial repetitive intergenic consensus–polymerase chain reaction (ERIC-PCR) analysis, nor with the genes avrBs2, XAC3090, and hpaF. Nei's genetic diversity indexes varied from 0.65 to 0.96 for subcollections of the pathogen. One or few haplotypes were most frequent in the strain collection, but several haplotypes were represented by solely one or few strains. The PthA4 probe resulted in the higher number of haplotypes identified in the Brazilian subcollections. Greater variation in the frequency of haplotypes occurred within subcollections (93.7%) than among subcollections. Only some haplotypes were genetically distant from all others, especially those originated from Rio Grande do Sul and Santa Catarina states. These bacterial effectors are widely spread in the collections and are useful for a better understanding of the host–pathogen interaction and the search for resistance genes in host and nonhost plants.

scholarly journals The Effect of Transcription Factor MYB14 on Defense Mechanisms in Vitis quinquangularis-Pingyi

2020 ◽  
Vol 21 (3) ◽  
pp. 706 ◽  
Author(s):  
Yangyang Luo ◽  
Qingyang Wang ◽  
Ru Bai ◽  
Ruixiang Li ◽  
Lu Chen ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Nicotiana Benthamiana ◽  
Defense Mechanisms ◽  
Qualitative Difference ◽  
Defense Responses ◽  
Molecular Pattern ◽  
Effector Triggered Immunity ◽  
Pathogen Associated Molecular Pattern ◽  
Basal Immunity ◽  
Stilbene Biosynthesis

In the current study, we identified a transcription factor, MYB14, from Chinese wild grape, Vitis quinquangularis-Pingyi (V. quinquangularis-PY), which could enhance the main stilbene contents and expression of stilbene biosynthesis genes (StSy/RS) by overexpression of VqMYB14. The promoter of VqMYB14 (pVqMYB14) was shown to be induced as part of both basal immunity (also called pathogen-associated molecular pattern (PAMP)-triggered immunity, PTI) and effector-triggered immunity (ETI), triggered by the elicitors flg22 and harpin, respectively. This was demonstrated by expression of pVqMYB14 in Nicotiana benthamiana and Vitis. We identified sequence differences, notably an 11 bp segment in pVqMYB14 that is important for the PTI/ETI, and particularly for the harpin-induced ETI response. In addition, we showed that activation of the MYB14 promoter correlates with differences in the expression of MYB14 and stilbene pattern induced by flg22 and harpin. An experimental model of upstream signaling in V. quinquangularis-PY is presented, where early defense responses triggered by flg22 and harpin partially overlap, but where the timing and levels differ. This translates into a qualitative difference with respect to patterns of stilbene accumulation.

Herbivore Oral Secreted Bacteria Trigger Distinct Defense Responses in Preferred and Non-Preferred Host Plants

2016 ◽  
Vol 42 (6) ◽  
pp. 463-474 ◽  
Author(s):  
Jie Wang ◽  
Seung Ho Chung ◽  
Michelle Peiffer ◽  
Cristina Rosa ◽  
Kelli Hoover ◽  
...  
Keyword(s):  
Host Plants ◽  
Defense Responses

scholarly journals Hop stunt viroid: Effect on Host (Humulus lupulus) Transcriptome and Its Interactions With Hop Powdery Mildew (Podospheara macularis)

2017 ◽  
Vol 30 (10) ◽  
pp. 842-851 ◽  
Author(s):  
Madhu Kappagantu ◽  
Jeff M. Bullock ◽  
Mark E. Nelson ◽  
Kenneth C. Eastwell
Keyword(s):  
Powdery Mildew ◽  
Transcriptome Analysis ◽  
Plant Pathogens ◽  
Polymerase Chain Reaction Analysis ◽  
Defense Responses ◽  
Pr Genes ◽  
Stunt Viroid ◽  
Hop Stunt Viroid ◽  
Pathogenesis Related ◽  
Host Metabolism

Viroids are the smallest known plant pathogens that exploit host systems for their replication and cause diseases in many hosts. In this study, the host response of hop plants to Hop stunt viroid (HSVd) infection was studied through transcriptome analysis. RNA sequence analysis of hop leaves infected with HSVd revealed dynamic changes in hop gene expression. Defense-related genes and genes involved in lipid and terpenoid metabolism are the major categories that showed differential expression due to HSVd infection. Additionally, the effect of HSVd on development of hop powdery mildew (Podospheara macularis) (HPM) was studied. Transcriptome analysis followed by quantitative reverse transcription-polymerase chain reaction analysis showed that transcript levels of pathogenesis-related (PR) genes such as PR protein 1, chitinase, and thaumatin-like protein genes are induced in leaves infected with HPM alone. The response in these genes to HPM is significantly down-regulated in leaves with HSVd-HPM mixed infection. These results confirm that HSVd alters host metabolism, physiology, and plant defense responses. Nevertheless, in detached leaf assays, HPM consistently expanded faster on HSVd-negative leaves relative to HSVd-positive leaves. Although HSVd infection suppresses elements associated with the host immunity response, infection by HSVd is antagonistic to HPM infection of hops.

scholarly journals Inducing Fungus-Resistance into Plants through Biotechnology

2010 ◽  
Vol 2 (2) ◽  
pp. 14-21 ◽  
Author(s):  
Shabir Hussain WANI
Keyword(s):  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Hydrolytic Enzymes ◽  
Defense Responses ◽  
Stilbene Synthase ◽  
Fungal Disease ◽  
Plant Diseases ◽  
Fungal Cell ◽  
Oxidase Gene ◽  
Enhanced Resistance

Plant diseases are caused by a variety of plant pathogens including fungi, and their management requires the use of techniques like transgenic technology, molecular biology, and genetics. There have been attempts to use gene technology as an alternative method to protect plants from microbial diseases, in addition to the development of novel agrochemicals and the conventional breeding of resistant cultivars. Various genes have been introduced into plants, and the enhanced resistance against fungi has been demonstrated. These include: genes that express proteins, peptides, or antimicrobial compounds that are directly toxic to pathogens or that reduce their growth in situ; gene products that directly inhibit pathogen virulence products or enhance plant structural defense genes, that directly or indirectly activate general plant defense responses; and resistance genes involved in the hypersensitive response and in the interactions with virulence factors. The introduction of the tabtoxin acetyltransferase gene, the stilbene synthase gene, the ribosome-inactivation protein gene and the glucose oxidase gene brought enhanced resistance in different plants. Genes encoding hydrolytic enzymes such as chitinase and glucanase, which can deteriorate fungal cell-wall components, are attractive candidates for this approach and are preferentially used for the production of fungal disease-resistant plants. In addition to this, RNA-mediated gene silencing is being tried as a reverse tool for gene targeting in plant diseases caused by fungal pathogens. In this review, different mechanisms of fungal disease resistance through biotechnological approaches are discussed and the recent advances in fungal disease management through transgenic approach are reviewed.

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