scholarly journals Two structurally different oomycete MAMPs induce distinctive plant immune responses.

2021 ◽  
Author(s):  
Mohammad Shahjahan Monjil ◽  
Hiroaki Kato ◽  
Kentaro Matsuda ◽  
Natsumi Suzuki ◽  
Shiho Tenhiro ◽  
...  
Keyword(s):  
Immune Responses ◽  
Cumulative Effect ◽  
Resistance Mechanisms ◽  
Ros Production ◽  
Oxygen Species ◽  
Biotic And Abiotic Stresses ◽  
Simultaneous Treatment ◽  
Oomycete Pathogen ◽  
Molecular Patterns ◽  
External Signals

Plants recognize a variety of external signals and induce appropriate mechanisms to increase their tolerance to biotic and abiotic stresses. Precise recognition of attacking pathogens and induction of effective resistance mechanisms are critical functions for plant survival. Some molecular patterns unique to a certain group of microbes (MAMPs, microbe-associated molecular patterns) are sensed by plant cells as non-self molecules via pattern recognition receptors. While a variety of MAMPs of bacterial and fungal origin have been identified, reports on MAMPs of oomycete pathogens are relatively limited. This study aimed to identify unique MAMP elicitors from the oomycete pathogen Phytophthora infestans, the causal agent of potato late blight. Using reactive oxygen species (ROS) production and phytoalexin production in potato as markers for the purification of oomycete elicitors, we identified two structurally different groups of elicitors, namely ceramides and diacylglycerols. P. infestans ceramide (Pi-Cer) elicitors induced ROS production, while diacylglycerol (Pi-DAG) elicitors, containing eicosapentaenoic acid (EPA) as a substructure, induced the formation of phytoalexins in potato. Pi-Cer and Pi-DAG are also contained in the mycelia of another oomycete pathogen Pythium aphanidermatum, indicating that they are MAMPs of oomycetes. When Arabidopsis was treated with Pi-Cer and EPA, partially overlapping but different sets of genes were induced. Furthermore, simultaneous treatment with Pi-Cer and EPA did not have a cumulative effect on induced genes, but rather the expression of some genes induced by EPA was attenuated by the co-treatment with Pi-Cer. These results indicate that plants may combine the signals from simultaneously recognized MAMP elicitors to specifically adapt the defense response to a particular pathogen.

scholarly journals Guarding the Green: Pathways to Stomatal Immunity

2013 ◽  
Vol 26 (6) ◽  
pp. 626-632 ◽  
Author(s):  
Katja Sawinski ◽  
Sophia Mersmann ◽  
Silke Robatzek ◽  
Maik Böhmer
Keyword(s):  
Water Availability ◽  
Abiotic Stresses ◽  
Stomatal Closure ◽  
Guard Cells ◽  
Oxygen Species ◽  
Biotic And Abiotic Stresses ◽  
Entry Site ◽  
Microbial Invasion ◽  
Active Immunity ◽  
Molecular Patterns

Guard cells regulate plant gas exchange and transpiration by modulation of stomatal aperture upon integrating external cues like photosynthetic effective illumination, CO2 levels and water availability and internal signals like abscisic acid (ABA). Being pores, stomata constitute a natural entry site for potentially harmful microbes. To prevent microbial invasion, stomata close upon perception of microbe-associated molecular patterns (MAMPs), and this represents an important layer of active immunity at the preinvasive level. The signaling pathways leading to stomatal closure triggered by biotic and abiotic stresses employ several common components, such as reactive oxygen species, calcium, kinases, and hormones, suggesting considerable intersection between MAMP- and ABA-induced stomatal closures, which we will discuss in this review.

scholarly journals Reactive Oxygen Species in Host Plant Are Required for an Early Defense Response against Attack of Stagonospora nodorum Berk. Necrotrophic Effectors SnTox

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1586
Author(s):  
Svetlana Veselova ◽  
Tatyana Nuzhnaya ◽  
Guzel Burkhanova ◽  
Sergey Rumyantsev ◽  
Igor Maksimov
Keyword(s):  
Reactive Oxygen Species ◽  
Early Stage ◽  
Reactive Oxygen ◽  
Triticum Aestivum L ◽  
Redox Status ◽  
Stagonospora Nodorum ◽  
Ros Generation ◽  
Ros Production ◽  
Oxygen Species ◽  
Necrotrophic Effectors

Reactive oxygen species (ROS) play a central role in plant immune responses. The most important virulence factors of the Stagonospora nodorum Berk. are multiple fungal necrotrophic effectors (NEs) (SnTox) that affect the redox-status and cause necrosis and/or chlorosis in wheat lines possessing dominant susceptibility genes (Snn). However, the effect of NEs on ROS generation at the early stages of infection has not been studied. We studied the early stage of infection of various wheat genotypes with S nodorum isolates -Sn4VD, SnB, and Sn9MN, carrying a different set of NE genes. Our results indicate that all three NEs of SnToxA, SnTox1, SnTox3 significantly contributed to cause disease, and the virulence of the isolates depended on their differential expression in plants (Triticum aestivum L.). The Tsn1–SnToxA, Snn1–SnTox1and Snn3–SnTox3 interactions played an important role in inhibition ROS production at the initial stage of infection. The Snn3–SnTox3 inhibited ROS production in wheat by affecting NADPH-oxidases, peroxidases, superoxide dismutase and catalase. The Tsn1–SnToxA inhibited ROS production in wheat by affecting peroxidases and catalase. The Snn1–SnTox1 inhibited the production of ROS in wheat by mainly affecting a peroxidase. Collectively, these results show that the inverse gene-for gene interactions between effector of pathogen and product of host sensitivity gene suppress the host’s own PAMP-triggered immunity pathway, resulting in NE-triggered susceptibility (NETS). These results are fundamentally changing our understanding of the development of this economical important wheat disease.

scholarly journals Production and scavenging of reactive oxygen species both affect reproductive success in male and female Drosophila melanogaster

2021 ◽  
Author(s):  
Biz R. Turnell ◽  
Luisa Kumpitsch ◽  
Klaus Reinhardt
Keyword(s):  
Reactive Oxygen Species ◽  
Drosophila Melanogaster ◽  
Reactive Oxygen ◽  
Cellular Aging ◽  
Ros Production ◽  
Oxygen Species ◽  
Wild Type ◽  
Ros Scavenging ◽  
Respiratory Pathway ◽  
Male And Female

AbstractSperm aging is accelerated by the buildup of reactive oxygen species (ROS), which cause oxidative damage to various cellular components. Aging can be slowed by limiting the production of mitochondrial ROS and by increasing the production of antioxidants, both of which can be generated in the sperm cell itself or in the surrounding somatic tissues of the male and female reproductive tracts. However, few studies have compared the separate contributions of ROS production and ROS scavenging to sperm aging, or to cellular aging in general. We measured reproductive fitness in two lines of Drosophila melanogaster genetically engineered to (1) produce fewer ROS via expression of alternative oxidase (AOX), an alternative respiratory pathway; or (2) scavenge fewer ROS due to a loss-of-function mutation in the antioxidant gene dj-1β. Wild-type females mated to AOX males had increased fecundity and longer fertility durations, consistent with slower aging in AOX sperm. Contrary to expectations, fitness was not reduced in wild-type females mated to dj-1β males. Fecundity and fertility duration were increased in AOX and decreased in dj-1β females, indicating that female ROS levels may affect aging rates in stored sperm and/or eggs. Finally, we found evidence that accelerated aging in dj-1β sperm may have selected for more frequent mating. Our results help to clarify the relative roles of ROS production and ROS scavenging in the male and female reproductive systems.

scholarly journals Multifunctional Role of Chitosan Edible Coatings on Antioxidant Systems in Fruit Crops: A Review

2021 ◽  
Vol 22 (5) ◽  
pp. 2633
Author(s):  
Giuseppina Adiletta ◽  
Marisa Di Matteo ◽  
Milena Petriccione
Keyword(s):  
State Of The Art ◽  
Antioxidant Systems ◽  
Edible Coatings ◽  
Ros Production ◽  
Oxygen Species ◽  
Fruit Crops ◽  
Oxidative Damages ◽  
Film Forming ◽  
Anti Oxidant

Chitosan-based edible coatings represent an eco-friendly and biologically safe preservative tool to reduce qualitative decay of fresh and ready-to-eat fruits during post-harvest life due to their lack of toxicity, biodegradability, film-forming properties, and antimicrobial actions. Chitosan-based coatings modulate or control oxidative stress maintaining in different manner the appropriate balance of reactive oxygen species (ROS) in fruit cells, by the interplay of pathways and enzymes involved in ROS production and the scavenging mechanisms which essentially constitute the basic ROS cycle. This review is carried out with the aim to provide comprehensive and updated over-view of the state of the art related to the effects of chitosan-based edible coatings on anti-oxidant systems, enzymatic and non-enzymatic, evaluating the induced oxidative damages during storage in whole and ready-to-eat fruits. All these aspects are broadly reviewed in this review, with particular emphasis on the literature published during the last five years.

scholarly journals Reactive oxygen species rescue regeneration after silencing the MAPK–ERK signaling pathway in Schmidtea mediterranea

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
V. Jaenen ◽  
S. Fraguas ◽  
K. Bijnens ◽  
M. Heleven ◽  
T. Artois ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Signaling Pathway ◽  
Reactive Oxygen ◽  
Light Therapy ◽  
Erk Signaling ◽  
Model Organisms ◽  
Ros Production ◽  
Oxygen Species ◽  
Planarian Regeneration ◽  
Egfr Signaling Pathway

AbstractDespite extensive research on molecular pathways controlling the process of regeneration in model organisms, little is known about the actual initiation signals necessary to induce regeneration. Recently, the activation of ERK signaling has been shown to be required to initiate regeneration in planarians. However, how ERK signaling is activated remains unknown. Reactive Oxygen Species (ROS) are well-known early signals necessary for regeneration in several models, including planarians. Still, the probable interplay between ROS and MAPK/ERK has not yet been described. Here, by interfering with major mediators (ROS, EGFR and MAPK/ERK), we were able to identify wound-induced ROS, and specifically H2O2, as upstream cues in the activation of regeneration. Our data demonstrate new relationships between regeneration-related ROS production and MAPK/ERK activation at the earliest regeneration stages, as well as the involvement of the EGFR-signaling pathway. Our results suggest that (1) ROS and/or H2O2 have the potential to rescue regeneration after MEK-inhibition, either by H2O2-treatment or light therapy, (2) ROS and/or H2O2 are required for the activation of MAPK/ERK signaling pathway, (3) the EGFR pathway can mediate ROS production and the activation of MAPK/ERK during planarian regeneration.

scholarly journals Somatic production of reactive oxygen species does not predict its production in sperm cells across Drosophila melanogaster lines

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Biz R. Turnell ◽  
Luisa Kumpitsch ◽  
Anne-Cécile Ribou ◽  
Klaus Reinhardt
Keyword(s):  
Reactive Oxygen Species ◽  
Drosophila Melanogaster ◽  
Reactive Oxygen ◽  
Future Research ◽  
Ros Production ◽  
Oxygen Species ◽  
Loss Of Function ◽  
Wild Type ◽  
Ros Scavenging ◽  
Transport Chain

Abstract Objective Sperm ageing has major evolutionary implications but has received comparatively little attention. Ageing in sperm and other cells is driven largely by oxidative damage from reactive oxygen species (ROS) generated by the mitochondria. Rates of organismal ageing differ across species and are theorized to be linked to somatic ROS levels. However, it is unknown whether sperm ageing rates are correlated with organismal ageing rates. Here, we investigate this question by comparing sperm ROS production in four lines of Drosophila melanogaster that have previously been shown to differ in somatic mitochondrial ROS production, including two commonly used wild-type lines and two lines with genetic modifications standardly used in ageing research. Results Somatic ROS production was previously shown to be lower in wild-type Oregon-R than in wild-type Dahomey flies; decreased by the expression of alternative oxidase (AOX), a protein that shortens the electron transport chain; and increased by a loss-of-function mutation in dj-1β, a gene involved in ROS scavenging. Contrary to predictions, we found no differences among these four lines in the rate of sperm ROS production. We discuss the implications of our results, the limitations of our study, and possible directions for future research.

scholarly journals The Role of Macrophages in the Host’s Defense against Sporothrix schenckii

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 905
Author(s):  
Estela Ruiz-Baca ◽  
Armando Pérez-Torres ◽  
Yolanda Romo-Lozano ◽  
Daniel Cervantes-García ◽  
Carlos A. Alba-Fierro ◽  
...  
Keyword(s):  
Immune Responses ◽  
Macrophage Polarization ◽  
Sporothrix Schenckii ◽  
Macrophage Cell ◽  
Cell Recruitment ◽  
Host Pathogen Interaction ◽  
Interaction Processes ◽  
Host Pathogen ◽  
Molecular Patterns

The role of immune cells associated with sporotrichosis caused by Sporothrix schenckii is not yet fully clarified. Macrophages through pattern recognition receptors (PRRs) can recognize pathogen-associated molecular patterns (PAMPs) of Sporothrix, engulf it, activate respiratory burst, and secrete pro-inflammatory or anti-inflammatory biological mediators to control infection. It is important to consider that the characteristics associated with S. schenckii and/or the host may influence macrophage polarization (M1/M2), cell recruitment, and the type of immune response (1, 2, and 17). Currently, with the use of new monocyte-macrophage cell lines, it is possible to evaluate different host–pathogen interaction processes, which allows for the proposal of new mechanisms in human sporotrichosis. Therefore, in order to contribute to the understanding of these host–pathogen interactions, the aim of this review is to summarize and discuss the immune responses induced by macrophage-S. schenckii interactions, as well as the PRRs and PAMPs involved during the recognition of S. schenckii that favor the immune evasion by the fungus.

scholarly journals Biomarkers of Radiotherapy-Induced Immunogenic Cell Death

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 930
Author(s):  
Rianne D. W. Vaes ◽  
Lizza E. L. Hendriks ◽  
Marc Vooijs ◽  
Dirk De Ruysscher
Keyword(s):  
Cell Death ◽  
Immune Responses ◽  
Tumor Cells ◽  
Immunogenic Cell Death ◽  
Type I ◽  
Future Studies ◽  
Regulated Cell Death ◽  
Molecular Patterns ◽  
Damage Associated Molecular Patterns ◽  
Potential Biomarkers

Radiation therapy (RT) can induce an immunogenic variant of regulated cell death that can initiate clinically relevant tumor-targeting immune responses. Immunogenic cell death (ICD) is accompanied by the exposure and release of damage-associated molecular patterns (DAMPs), chemokine release, and stimulation of type I interferon (IFN-I) responses. In recent years, intensive research has unraveled major mechanistic aspects of RT-induced ICD and has resulted in the identification of immunogenic factors that are released by irradiated tumor cells. However, so far, only a limited number of studies have searched for potential biomarkers that can be used to predict if irradiated tumor cells undergo ICD that can elicit an effective immunogenic anti-tumor response. In this article, we summarize the available literature on potential biomarkers of RT-induced ICD that have been evaluated in cancer patients. Additionally, we discuss the clinical relevance of these findings and important aspects that should be considered in future studies.

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