scholarly journals Priming of Plant Defenses against Ophiostoma novo-ulmi by Elm (Ulmus minor Mill.) Fungal Endophytes

2021 ◽  
Vol 7 (9) ◽  
pp. 687
Author(s):  
Clara Martínez-Arias ◽  
Juan Sobrino-Plata ◽  
Luis Gil ◽  
Jesús Rodríguez-Calcerrada ◽  
Juan Antonio Martín
Keyword(s):  
Host Resistance ◽  
Current Knowledge ◽  
Fungal Endophytes ◽  
Antioxidant Response ◽  
Plant Diseases ◽  
Dutch Elm Disease ◽  
Forest Trees ◽  
Variable Intensity ◽  
Defense Priming ◽  
Ulmus Minor

Some fungal endophytes of forest trees are recognized as beneficial symbionts against stresses. In previous works, two elm endophytes from the classes Cystobasidiomycetes and Eurotiomycetes promoted host resistance to abiotic stress, and another elm endophyte from Dothideomycetes enhanced host resistance to Dutch elm disease (DED). Here, we hypothesize that the combined effect of these endophytes activate the plant immune and/or antioxidant system, leading to a defense priming and/or increased oxidative protection when exposed to the DED pathogen Ophiostoma novo-ulmi. To test this hypothesis, the short-term defense gene activation and antioxidant response were evaluated in DED-susceptible (MDV1) and DED-resistant (VAD2 and MDV2.3) Ulmus minor genotypes inoculated with O. novo-ulmi, as well as two weeks earlier with a mixture of the above-mentioned endophytes. Endophyte inoculation induced a generalized transient defense activation mediated primarily by salicylic acid (SA). Subsequent pathogen inoculation resulted in a primed defense response of variable intensity among genotypes. Genotypes MDV1 and VAD2 displayed a defense priming driven by SA, jasmonic acid (JA), and ethylene (ET), causing a reduced pathogen spread in MDV1. Meanwhile, the genotype MDV2.3 showed lower defense priming but a stronger and earlier antioxidant response. The defense priming stimulated by elm fungal endophytes broadens our current knowledge of the ecological functions of endophytic fungi in forest trees and opens new prospects for their use in the biocontrol of plant diseases.

scholarly journals Endophyte inoculation enhances Ulmus minor resistance to Dutch elm disease

2020 ◽  
Author(s):  
C Martínez-Arias ◽  
J Sobrino-Plata ◽  
S Ormeño-Moncalvillo ◽  
L Gil ◽  
J Rodríguez-Calcerrada ◽  
...  
Keyword(s):  
Fungal Endophytes ◽  
Nutrient Utilization ◽  
Dutch Elm Disease ◽  
Total Phenolic ◽  
Phenotypic Traits ◽  
Total Phenolic Compounds ◽  
Biotic Stresses ◽  
Ulmus Minor ◽  
Utilization Patterns

AbstractCertain fungal endophytes are known to improve plant resistance to biotic stresses in forest trees. In this study, three stem fungal endophytes belonging to classes Cystobasidiomycetes, Eurotiomycetes and Dothideomycetes were selected from 210 isolates for their potential as enhancers of Ulmus minor resistance to Ophiostoma novo-ulmi. We evaluated phenotypic traits of these endophytes that could be beneficial for inhibiting O. novo-ulmi in the host plant. Under in vitro conditions, the Dothideomycetous isolate YCB36 strongly inhibited O. novo-ulmi growth, released antipathogenic VOCs, chitinases and siderophores, and overlapped with the pathogen in nutrient utilization patterns. These functional traits could explain the 40% reduction in leaf wilting due to O. novo-ulmi in elm trees pre-inoculated with this endophyte. Ulmus minor trees inoculated with this endophyte showed increased leaf stomatal conductance and higher concentrations of flavonoids and total phenolic compounds in xylem tissues, suggesting induction of defence metabolism.

scholarly journals Modulation of Nrf2 and NF-κB Signaling Pathways by Naturally Occurring Compounds in Relation to Cancer Prevention and Therapy. Are Combinations Better Than Single Compounds?

2021 ◽  
Vol 22 (15) ◽  
pp. 8223
Author(s):  
Violetta Krajka-Kuźniak ◽  
Wanda Baer-Dubowska
Keyword(s):  
Cancer Prevention ◽  
Signaling Pathways ◽  
Current Knowledge ◽  
Cancer Chemoprevention ◽  
Antioxidant Response ◽  
Natural Food ◽  
Related Factor ◽  
Nuclear Factor ◽  
Edible Plant ◽  
Prevention And Therapy

Nrf2 (nuclear factor erythroid 2-related factor 2) and NF-κB (nuclear factor–kappa B) signaling pathways play a central role in suppressing or inducing inflammation and angiogenesis processes. Therefore, they are involved in many steps of carcinogenesis through cooperation with multiple signaling molecules and pathways. Targeting both transcription factors simultaneously may be considered an equally important strategy for cancer chemoprevention and therapy. Several hundreds of phytochemicals, mainly edible plant and vegetable components, were shown to activate Nrf2 and mediate antioxidant response. A similar number of phytochemicals was revealed to affect NF-κB. While activation of Nrf2 and inhibition of NF-κB may protect normal cells against cancer initiation and promotion, enhanced expression and activation in cancer cells may lead to resistance to conventional chemo- or radiotherapy. Most phytochemicals, through different mechanisms, activate Nrf2, but others, such as luteolin, can act as inhibitors of both Nrf2 and NF-κB. Despite many experimental data confirming the above mechanisms currently, limited evidence exists demonstrating such activity in humans. Combinations of phytochemicals resembling that in a natural food matrix but allowing higher concentrations may improve their modulating effect on Nrf2 and NF-κB and ultimately cancer prevention and therapy. This review presents the current knowledge on the effect of selected phytochemicals and their combinations on Nrf2 and NF-κB activities in the above context.

scholarly journals Alive and kicking, or, living on borrowed time? – Microsatellite diversity in natural populations of the endangered Ulmus minor Mill. sensu latissimo from Croatia

2016 ◽  
Vol 75 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Marko Zebec ◽  
Marilena Idžojtić ◽  
Zlatko Šatović ◽  
Igor Poljak ◽  
Zlatko Liber
Keyword(s):  
Genetic Diversity ◽  
Natural Populations ◽  
Genetic Bottleneck ◽  
Dutch Elm Disease ◽  
Significant Excess ◽  
Mediterranean Populations ◽  
Ulmus Minor ◽  
Study Results ◽  
The Impact ◽  
Microsatellite Diversity

AbstractThe main objective of this research was to assess the genetic diversity of 5 natural field elm populations in Croatia. The study results suggest that the observed populations are characterized by a satisfactory amount of heterozygosity, and that the impact of the Dutch elm disease on the amount of genetic diversity in the sampled populations is currently negligible. However, one population displayed a significant excess of heterozygosity, implying a genetic bottleneck. The existence of a very clear genetic differentiation between the continental and the Mediterranean populations of Ulmus minor in Croatia was noticed.

scholarly journals Optimizing Plant Disease Management in Agricultural Ecosystems Through Rational In-Crop Diversification

2021 ◽  
Vol 12 ◽  
Author(s):  
Yan-Ping Wang ◽  
Zhe-Chao Pan ◽  
Li-Na Yang ◽  
Jeremy J. Burdon ◽  
Hanna Friberg ◽  
...  
Keyword(s):  
Late Blight ◽  
Host Resistance ◽  
Control Plant ◽  
Late Blight Resistance ◽  
Plant Diseases ◽  
Crop Diversification ◽  
Agricultural Ecosystems ◽  
Potato Varieties ◽  
Plant Disease Management ◽  
Disease Epidemics

Biodiversity plays multifaceted roles in societal development and ecological sustainability. In agricultural ecosystems, using biodiversity to mitigate plant diseases has received renewed attention in recent years but our knowledge of the best ways of using biodiversity to control plant diseases is still incomplete. In term of in-crop diversification, it is not clear how genetic diversity per se in host populations interacts with identifiable resistance and other functional traits of component genotypes to mitigate disease epidemics and what is the best way of structuring mixture populations. In this study, we created a series of host populations by mixing different numbers of potato varieties showing different late blight resistance levels in different proportions. The amount of naturally occurring late blight disease in the mixture populations was recorded weekly during the potato growing seasons. The percentage of disease reduction (PDR) in the mixture populations was calculated by comparing their observed late blight levels relative to that expected when they were planted in pure stands. We found that PDR in the mixtures increased as the number of varieties and the difference in host resistance (DHR) between the component varieties increased. However, the level of host resistance in the potato varieties had little impact on PDR. In mixtures involving two varieties, the optimum proportion of component varieties for the best PDR depended on their DHR, with an increasing skewness to one of the component varieties as the DHR between the component varieties increased. These results indicate that mixing crop varieties can significantly reduce disease epidemics in the field. To achieve the best disease mitigation, growers should include as many varieties as possible in mixtures or, if only two component mixtures are possible, increase DHR among the component varieties.

scholarly journals Overexpression of mqsR in Xylella fastidiosa Leads to a Priming Effect of Cells to Copper Stress Tolerance

2021 ◽  
Vol 12 ◽  
Author(s):  
Isis Gabriela Barbosa Carvalho ◽  
Marcus Vinicius Merfa ◽  
Natália Sousa Teixeira-Silva ◽  
Paula Maria Moreira Martins ◽  
Marco Aurélio Takita ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Current Knowledge ◽  
Xylella Fastidiosa ◽  
Cell Formation ◽  
Cell Aggregation ◽  
Plant Diseases ◽  
Copper Tolerance ◽  
Copper Stress ◽  
Economic Damage ◽  
Environmental Damage

Copper-based compounds are widely used in agriculture as a chemical strategy to limit the spread of multiple plant diseases; however, the continuous use of this heavy metal has caused environmental damage as well as the development of copper-resistant strains. Thus, it is important to understand how the bacterial phytopathogens evolve to manage with this metal in the field. The MqsRA Toxin–Antitoxin system has been recently described for its function in biofilm formation and copper tolerance in Xylella fastidiosa, a plant-pathogen bacterium responsible for economic damage in several crops worldwide. Here we identified differentially regulated genes by X. fastidiosa MqsRA by assessing changes in global gene expression with and without copper. Results show that mqsR overexpression led to changes in the pattern of cell aggregation, culminating in a global phenotypic heterogeneity, indicative of persister cell formation. This phenotype was also observed in wild-type cells but only in the presence of copper. This suggests that MqsR regulates genes that alter cell behavior in order to prime them to respond to copper stress, which is supported by RNA-Seq analysis. To increase cellular tolerance, proteolysis and efflux pumps and regulator related to multidrug resistance are induced in the presence of copper, in an MqsR-independent response. In this study we show a network of genes modulated by MqsR that is associated with induction of persistence in X. fastidiosa. Persistence in plant-pathogenic bacteria is an important genetic tolerance mechanism still neglected for management of phytopathogens in agriculture, for which this work expands the current knowledge and opens new perspectives for studies aiming for a more efficient control in the field.

scholarly journals Effects of Deoxynivalenol and Fumonisins on Broiler Gut Cytoprotective Capacity

Toxins ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 729
Author(s):  
Vasileios Paraskeuas ◽  
Eirini Griela ◽  
Dimitrios Bouziotis ◽  
Konstantinos Fegeros ◽  
Gunther Antonissen ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Antioxidant Response ◽  
Cytochrome P450 Enzyme ◽  
Poultry Production ◽  
Gut Health ◽  
Bioactive Components ◽  
Site Specific ◽  
Aryl Hydrocarbon ◽  
Crucial Problem ◽  
P450 Enzyme

Mycotoxins are a crucial problem for poultry production worldwide. Two of the most frequently found mycotoxins in feedstuffs are deoxynivalenol (DON) and fumonisins (FUM) which adversely affect gut health and poultry performance. The current knowledge on DON and FUM effects on broiler responses relevant for gut detoxification, antioxidant capacity, and health is still unclear. The aim of this study was to assess a range of selected molecular intestinal biomarkers for their responsiveness to the maximum allowable European Union dietary levels for DON (5 mg/kg) and FUM (20 mg/kg) in broilers. For the experimental purpose, a challenge diet was formulated, and biomarkers relevant for detoxification, antioxidant response, stress, inflammation, and integrity were profiled across the broiler intestine. The results reveal that DON significantly (p < 0.05) induced aryl hydrocarbon receptor (AhR) and cytochrome P450 enzyme (CYP) expression mainly at the duodenum. Moreover, DON and FUM had specific significant (p < 0.05) effects on the antioxidant response, stress, inflammation, and integrity depending on the intestinal segment. Consequently, broiler molecular responses to DON and FUM assessed via a powerful palette of biomarkers were shown to be mycotoxin and intestinal site specific. The study findings could be highly relevant for assessing various dietary bioactive components for protection against mycotoxins.

scholarly journals Preventing Oxidative Stress in the Liver: An Opportunity for GLP-1 and/or PASK

Antioxidants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2028
Author(s):  
Verónica Hurtado-Carneiro ◽  
Pilar Dongil ◽  
Ana Pérez-García ◽  
Elvira Álvarez ◽  
Carmen Sanz
Keyword(s):  
Oxidative Stress ◽  
Histone Deacetylases ◽  
Current Knowledge ◽  
Mammalian Target Of Rapamycin ◽  
Antioxidant Response ◽  
Antioxidant Mechanism ◽  
Obesity And Diabetes ◽  
Pas Kinase ◽  
Glucagon Like Peptide 1 ◽  
Functional Inactivation

The liver’s high metabolic activity and detoxification functions generate reactive oxygen species, mainly through oxidative phosphorylation in the mitochondria of hepatocytes. In contrast, it also has a potent antioxidant mechanism for counterbalancing the oxidant’s effect and relieving oxidative stress. PAS kinase (PASK) is a serine/threonine kinase containing an N-terminal Per-Arnt-Sim (PAS) domain, able to detect redox state. During fasting/feeding changes, PASK regulates the expression and activation of critical liver proteins involved in carbohydrate and lipid metabolism and mitochondrial biogenesis. Interestingly, the functional inactivation of PASK prevents the development of a high-fat diet (HFD)-induced obesity and diabetes. In addition, PASK deficiency alters the activity of other nutrient sensors, such as the AMP-activated protein kinase (AMPK) and the mammalian target of rapamycin (mTOR). In addition to the expression and subcellular localization of nicotinamide-dependent histone deacetylases (SIRTs). This review focuses on the relationship between oxidative stress, PASK, and other nutrient sensors, updating the limited knowledge on the role of PASK in the antioxidant response. We also comment on glucagon-like peptide 1 (GLP-1) and its collaboration with PASK in preventing the damage associated with hepatic oxidative stress. The current knowledge would suggest that PASK inhibition and/or exendin-4 treatment, especially under fasting conditions, could ameliorate disorders associated with excess oxidative stress.

scholarly journals Cellulose Nanofibers from a Dutch Elm Disease-Resistant Ulmus minor Clone

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2450 ◽  
Author(s):  
Laura Jiménez-López ◽  
María E. Eugenio ◽  
David Ibarra ◽  
Margarita Darder ◽  
Juan A. Martín ◽  
...  
Keyword(s):  
Cellulose Nanofibers ◽  
Barrier Properties ◽  
Dutch Elm Disease ◽  
Ulmus Minor ◽  
Mechanical Pretreatment ◽  
Pfi Refining ◽  
First Time ◽  
Mediated Oxidation ◽  
Potential Use ◽  
Selection Of

The potential use of elm wood in lignocellulosic industries has been hindered by the Dutch elm disease (DED) pandemics, which have ravaged European and North American elm groves in the last century. However, the selection of DED-resistant cultivars paves the way for their use as feedstock in lignocellulosic biorefineries. Here, the production of cellulose nanofibers from the resistant Ulmus minor clone Ademuz was evaluated for the first time. Both mechanical (PFI refining) and chemical (TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidation) pretreatments were assessed prior to microfluidization, observing not only easier fibrillation but also better optical and barrier properties for elm nanopapers compared to eucalyptus ones (used as reference). Furthermore, mechanically pretreated samples showed higher strength for elm nanopapers. Although lower nanofibrillation yields were obtained by mechanical pretreatment, nanofibers showed higher thermal, mechanical and barrier properties, compared to TEMPO-oxidized nanofibers. Furthermore, lignin-containing elm nanofibers presented the most promising characteristics, with slightly lower transparencies.

scholarly journals Innovation and Application of the Type III Secretion System Inhibitors in Plant Pathogenic Bacteria

2020 ◽  
Vol 8 (12) ◽  
pp. 1956
Author(s):  
Xiaochen Yuan ◽  
Manda Yu ◽  
Ching-Hong Yang
Keyword(s):  
Type Iii Secretion ◽  
Pathogenic Bacteria ◽  
Plant Pathogens ◽  
Current Knowledge ◽  
Type Iii Secretion System ◽  
Transcriptional Regulators ◽  
Secretion System ◽  
Plant Diseases ◽  
Host Cells ◽  
Type Iii

Many Gram-negative pathogenic bacteria rely on a functional type III secretion system (T3SS), which injects multiple effector proteins into eukaryotic host cells, for their pathogenicity. Genetic studies conducted in different host-microbe pathosystems often revealed a sophisticated regulatory mechanism of their T3SSs, suggesting that the expression of T3SS is tightly controlled and constantly monitored by bacteria in response to the ever-changing host environment. Therefore, it is critical to understand the regulation of T3SS in pathogenic bacteria for successful disease management. This review focuses on a model plant pathogen, Dickeyadadantii, and summarizes the current knowledge of its T3SS regulation. We highlight the roles of several T3SS regulators that were recently discovered, including the transcriptional regulators: FlhDC, RpoS, and SlyA; the post-transcriptional regulators: PNPase, Hfq with its dependent sRNA ArcZ, and the RsmA/B system; and the bacterial second messenger cyclic-di-GMP (c-di-GMP). Homologs of these regulatory components have also been characterized in almost all major bacterial plant pathogens like Erwiniaamylovora, Pseudomonassyringae, Pectobacterium spp., Xanthomonas spp., and Ralstonia spp. The second half of this review shifts focus to an in-depth discussion of the innovation and development of T3SS inhibitors, small molecules that inhibit T3SSs, in the field of plant pathology. This includes T3SS inhibitors that are derived from plant phenolic compounds, plant coumarins, and salicylidene acylhydrazides. We also discuss their modes of action in bacteria and application for controlling plant diseases.

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