scholarly journals Nep1-like proteins as a target for plant pathogen control

2021 ◽  
Vol 17 (4) ◽  
pp. e1009477
Author(s):  
Katja Pirc ◽  
Vesna Hodnik ◽  
Tina Snoj ◽  
Tea Lenarčič ◽  
Simon Caserman ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Economic Losses ◽  
Ion Leakage ◽  
Tobacco Leaves ◽  
Global Food Security ◽  
Plant Infection ◽  
Promising Target ◽  
Pathogen Control ◽  
Global Food ◽  
Plant Plasma Membrane

The lack of efficient methods to control the major diseases of crops most important to agriculture leads to huge economic losses and seriously threatens global food security. Many of the most important microbial plant pathogens, including bacteria, fungi, and oomycetes, secrete necrosis- and ethylene-inducing peptide 1 (Nep1)-like proteins (NLPs), which critically contribute to the virulence and spread of the disease. NLPs are cytotoxic to eudicot plants, as they disturb the plant plasma membrane by binding to specific plant membrane sphingolipid receptors. Their pivotal role in plant infection and broad taxonomic distribution makes NLPs a promising target for the development of novel phytopharmaceutical compounds. To identify compounds that bind to NLPs from the oomycetes Pythium aphanidermatum and Phytophthora parasitica, a library of 587 small molecules, most of which are commercially unavailable, was screened by surface plasmon resonance. Importantly, compounds that exhibited the highest affinity to NLPs were also found to inhibit NLP-mediated necrosis in tobacco leaves and Phytophthora infestans growth on potato leaves. Saturation transfer difference-nuclear magnetic resonance and molecular modelling of the most promising compound, anthranilic acid derivative, confirmed stable binding to the NLP protein, which resulted in decreased necrotic activity and reduced ion leakage from tobacco leaves. We, therefore, confirmed that NLPs are an appealing target for the development of novel phytopharmaceutical agents and strategies, which aim to directly interfere with the function of these major microbial virulence factors. The compounds identified in this study represent lead structures for further optimization and antimicrobial product development.

scholarly journals Chp8, a Diguanylate Cyclase from Pseudomonas syringae pv. Tomato DC3000, Suppresses the Pathogen-Associated Molecular Pattern Flagellin, Increases Extracellular Polysaccharides, and Promotes Plant Immune Evasion

mBio ◽  
2014 ◽  
Vol 5 (3) ◽  
Author(s):  
Christoph Engl ◽  
Christopher J. Waite ◽  
Joseph F. McKenna ◽  
Mark H. Bennett ◽  
Thorsten Hamann ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Plant Pathogen ◽  
Crop Yields ◽  
Economic Losses ◽  
Extracellular Polysaccharides ◽  
Content Type ◽  
Global Food Security ◽  
Plant Infection ◽  
Molecular Pattern ◽  
Global Food

ABSTRACTThe bacterial plant pathogenPseudomonas syringaecauses disease in a wide range of plants. The associated decrease in crop yields results in economic losses and threatens global food security. Competition exists between the plant immune system and the pathogen, the basic principles of which can be applied to animal infection pathways.P. syringaeuses a type III secretion system (T3SS) to deliver virulence factors into the plant that promote survival of the bacterium. TheP. syringaeT3SS is a product of the hypersensitive response and pathogenicity (hrp) and hypersensitive response and conserved (hrc) gene cluster, which is strictly controlled by the codependent enhancer-binding proteins HrpR and HrpS. Through a combination of bacterial gene regulation and phenotypic studies, plant infection assays, and plant hormone quantifications, we now report that Chp8 (i) is embedded in the Hrp regulon and expressed in response to plant signals and HrpRS, (ii) is a functional diguanylate cyclase, (iii) decreases the expression of the major pathogen-associated molecular pattern (PAMP) flagellin and increases extracellular polysaccharides (EPS), and (iv) impacts the salicylic acid/jasmonic acid hormonal immune response and disease progression. We propose that Chp8 expression dampens PAMP-triggered immunity during early plant infection.IMPORTANCEThe global demand for food is projected to rise by 50% by 2030 and, as such, represents one of the major challenges of the 21st century, requiring improved crop management. Diseases caused by plant pathogens decrease crop yields, result in significant economic losses, and threaten global food security. Gaining mechanistic insights into the events at the plant-pathogen interface and employing this knowledge to make crops more resilient is one important strategy for improving crop management. Plant-pathogen interactions are characterized by the sophisticated interplay between plant immunity elicited upon pathogen recognition and immune evasion by the pathogen. Here, we identify Chp8 as a contributor to the major effort of the plant pathogenPseudomonas syringaepv. tomato DC3000 to evade immune responses of the plant.

scholarly journals Lipopeptides as the Antifungal and Antibacterial Agents: Applications in Food Safety and Therapeutics

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Khem Raj Meena ◽  
Shamsher S. Kanwar
Keyword(s):  
Antimicrobial Agents ◽  
Antibacterial Activities ◽  
Plant Diseases ◽  
Biologically Active ◽  
Economic Losses ◽  
Biological Origin ◽  
Global Food Security ◽  
Wide Range ◽  
Potential Inhibitors ◽  
Global Food

A lot of crops are destroyed by the phytopathogens such as fungi, bacteria, and yeast leading to economic losses to the farmers. Members of theBacillusgenus are considered as the factories for the production of biologically active molecules that are potential inhibitors of growth of phytopathogens. Plant diseases constitute an emerging threat to global food security. Many of the currently available antimicrobial agents for agriculture are highly toxic and nonbiodegradable and thus cause extended environmental pollution. Moreover, an increasing number of phytopathogens have developed resistance to antimicrobial agents. The lipopeptides have been tried as potent versatile weapons to deal with a variety of phytopathogens. All the three families ofBacilluslipopeptides, namely, Surfactins, Iturins and Fengycins, have been explored for their antagonistic activities towards a wide range of phytopathogens including bacteria, fungi, and oomycetes. Iturin and Fengycin have antifungal activities, while Surfactin has broad range of potent antibacterial activities and this has also been used as larvicidal agent. Interestingly, lipopeptides being the molecules of biological origin are environmentally acceptable.

scholarly journals Microbial threat– a growing challenge for plant biosecurity

2012 ◽  
Vol 33 (1) ◽  
pp. 12 ◽  
Author(s):  
Simon McKirdy ◽  
Brendan Rodoni ◽  
Jane Moran ◽  
Shashi Sharma
Keyword(s):  
Plant Pathogens ◽  
Market Access ◽  
Health And Safety ◽  
Production Costs ◽  
Microbial Pathogens ◽  
Global Food Security ◽  
Travel And Tourism ◽  
Increasing Risk ◽  
Global Food ◽  
Lower Production

Australia is relatively free from many of the plant pathogens that seriously impact on agricultural production and natural environment in other countries. This provides a valuable competitive advantage for Australia?s plant industries in terms of securing market access and maintaining lower production costs. The increasing growth in global trade, travel and tourism is exposing Australia?s plant industries and environment to ever-increasing risk of exotic microbial pathogens. At risk are approximately $14 billion per annum in crop exports, the environment and its associated tourism, the sustainability of regional communities with plant industries contributing approximately $25 billion annually, and indirectly animal and human health and safety. In addition, biosecurity threats are recognised as a serious risk to global food security.

scholarly journals Enzymatic degradation is an effective means to reduce aflatoxin contamination in maize

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Monica A. Schmidt ◽  
Yizhou Mao ◽  
Joseph Opoku ◽  
Hillary L. Mehl
Keyword(s):  
Post Infection ◽  
Effective Means ◽  
Aflatoxin Contamination ◽  
Economic Losses ◽  
Degrading Enzyme ◽  
Global Food Security ◽  
Embryo Tissue ◽  
Cellular Compartmentalization ◽  
Maize Kernels ◽  
Global Food

Abstract Background Aflatoxins are carcinogenic compounds produced by certain species of Aspergillus fungi. The consumption of crops contaminated with this toxin cause serious detrimental health effects, including death, in both livestock and humans. As a consequence, both the detection and quantification of this toxin in food/feed items is tightly regulated with crops exceeding the allowed limits eliminated from food chains. Globally, this toxin causes massive agricultural and economic losses each year. Results In this paper we investigate the feasibility of using an aflatoxin-degrading enzyme strategy to reduce/eliminate aflatoxin loads in developing maize kernels. We used an endoplasmic reticulum (ER) targeted sub-cellular compartmentalization stabilizing strategy to accumulate an aflatoxin-degrading enzyme isolated from the edible Honey mushroom Armillariella tabescens and expressed it in embryo tissue in developing maize kernels. Three transgenic maize lines that were determined to be expressing the aflatoxin-degrading enzyme both at the RNA and protein level, were challenged with the aflatoxin-producing strain Aspergillus flavus AF13 and shown to accumulate non-detectable levels of aflatoxin at 14-days post-infection and significantly reduced levels of aflatoxin at 30-days post-infection compared to nontransgenic control Aspergillus-challenged samples. Conclusions The expression of an aflatoxin-degrading enzyme in developing maize kernels was shown to be an effective means to control aflatoxin in maize in pre-harvest conditions. This aflatoxin-degradation strategy could play a significant role in the enhancement of both US and global food security and sustainability.

scholarly journals NLR immune receptor-nanobody fusions confer plant disease resistance

2021 ◽  
Author(s):  
Jiorgos Kourelis ◽  
Clemence Marchal ◽  
Sophien Kamoun
Keyword(s):  
Plant Disease Resistance ◽  
Plant Disease ◽  
Plant Pathogens ◽  
Fluorescent Proteins ◽  
Plant Viruses ◽  
Immune Receptor ◽  
Global Food Security ◽  
Immune Receptors ◽  
Natural Components ◽  
Global Food

Plant pathogens cause recurrent epidemics that threaten crop yield and global food security. Efforts to retool the plant immune system have been limited to modifying natural components and can be nullified by the emergence of new pathogen races. Therefore, there is a need to develop made-to-order synthetic plant immune receptors with resistance tailored to the pathogen genotypes present in the field. Here we show that plant immune receptors can be used as scaffolds for VHH nanobody fusions that bind fluorescent proteins (FPs). The receptor-nanobody fusions signal in the presence of the corresponding FP and confer resistance against plant viruses expressing FPs. Given that nanobodies can be raised against virtually any molecule, immune receptor-nanobody fusions have the potential to generate resistance against all major plant pathogens and pests.

The Genome Biology of Effector Gene Evolution in Filamentous Plant Pathogens

2018 ◽  
Vol 56 (1) ◽  
pp. 21-40 ◽  
Author(s):  
Andrea Sánchez-Vallet ◽  
Simone Fouché ◽  
Isabelle Fudal ◽  
Fanny E. Hartmann ◽  
Jessica L. Soyer ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Population Genomics ◽  
Gene Evolution ◽  
Point Mutations ◽  
Repetitive Elements ◽  
Genome Biology ◽  
Global Food Security ◽  
Effector Genes ◽  
Genes Encoding ◽  
Global Food

Filamentous pathogens, including fungi and oomycetes, pose major threats to global food security. Crop pathogens cause damage by secreting effectors that manipulate the host to the pathogen's advantage. Genes encoding such effectors are among the most rapidly evolving genes in pathogen genomes. Here, we review how the major characteristics of the emergence, function, and regulation of effector genes are tightly linked to the genomic compartments where these genes are located in pathogen genomes. The presence of repetitive elements in these compartments is associated with elevated rates of point mutations and sequence rearrangements with a major impact on effector diversification. The expression of many effectors converges on an epigenetic control mediated by the presence of repetitive elements. Population genomics analyses showed that rapidly evolving pathogens show high rates of turnover at effector loci and display a mosaic in effector presence-absence polymorphism among strains. We conclude that effective pathogen containment strategies require a thorough understanding of the effector genome biology and the pathogen's potential for rapid adaptation.

scholarly journals Rice Blast: A Disease with Implications for Global Food Security

Agronomy ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 451 ◽  
Author(s):  
Aziiba Emmanuel Asibi ◽  
Qiang Chai ◽  
Jeffrey A. Coulter
Keyword(s):  
Food Security ◽  
Environmental Conditions ◽  
Rice Blast ◽  
Crop Residues ◽  
Oryza Sativa L ◽  
Rice Production ◽  
Limiting Factors ◽  
Economic Losses ◽  
Global Food Security ◽  
Global Food

Rice blast is a serious fungal disease of rice (Oryza sativa L.) that is threatening global food security. It has been extensively studied due to the importance of rice production and consumption, and because of its vast distribution and destructiveness across the world. Rice blast, caused by Pyricularia oryzae Cavara 1892 (A), can infect aboveground tissues of rice plants at any growth stage and cause total crop failure. The pathogen produces lesions on leaves (leaf blast), leaf collars (collar blast), culms, culm nodes, panicle neck nodes (neck rot), and panicles (panicle blast), which vary in color and shape depending on varietal resistance, environmental conditions, and age. Understanding how rice blast is affected by environmental conditions at the cellular and genetic level will provide critical insight into incidence of the disease in future climates for effective decision-making and management. Integrative strategies are required for successful control of rice blast, including chemical use, biocontrol, selection of advanced breeding lines and cultivars with resistance genes, investigating genetic diversity and virulence of the pathogen, forecasting and mapping distribution of the disease and pathogen races, and examining the role of wild rice and weeds in rice blast epidemics. These tactics should be integrated with agronomic practices including the removal of crop residues to decrease pathogen survival, crop and land rotations, avoiding broadcast planting and double cropping, water management, and removal of yield-limiting factors for rice production. Such an approach, where chemical use is based on crop injury and estimated yield and economic losses, is fundamental for the sustainable control of rice blast to improve rice production for global food security.

scholarly journals Divergent abiotic spectral pathways unravel pathogen stress signals across species

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
P. J. Zarco-Tejada ◽  
T. Poblete ◽  
C. Camino ◽  
V. Gonzalez-Dugo ◽  
R. Calderon ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Socioeconomic Impact ◽  
Screening Methods ◽  
Yield Losses ◽  
Global Food Security ◽  
Plant Pest ◽  
Physiological Alterations ◽  
Food Deficit ◽  
Stress Signals ◽  
Global Food

AbstractPlant pathogens pose increasing threats to global food security, causing yield losses that exceed 30% in food-deficit regions. Xylella fastidiosa (Xf) represents the major transboundary plant pest and one of the world’s most damaging pathogens in terms of socioeconomic impact. Spectral screening methods are critical to detect non-visual symptoms of early infection and prevent spread. However, the subtle pathogen-induced physiological alterations that are spectrally detectable are entangled with the dynamics of abiotic stresses. Here, using airborne spectroscopy and thermal scanning of areas covering more than one million trees of different species, infections and water stress levels, we reveal the existence of divergent pathogen- and host-specific spectral pathways that can disentangle biotic-induced symptoms. We demonstrate that uncoupling this biotic–abiotic spectral dynamics diminishes the uncertainty in the Xf detection to below 6% across different hosts. Assessing these deviating pathways against another harmful vascular pathogen that produces analogous symptoms, Verticillium dahliae, the divergent routes remained pathogen- and host-specific, revealing detection accuracies exceeding 92% across pathosystems. These urgently needed hyperspectral methods advance early detection of devastating pathogens to reduce the billions in crop losses worldwide.

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