scholarly journals Arabidopsis PAD4 lipase-like domain is a minimal functional unit in resistance to green peach aphid

2019 ◽  
Author(s):  
Joram A. Dongus ◽  
Deepak D. Bhandari ◽  
Monika Patel ◽  
Lani Archer ◽  
Lucas Dijkgraaf ◽  
...  
Keyword(s):  
Plant Defense ◽  
Functional Unit ◽  
Green Peach Aphid ◽  
Molecular Evidence ◽  
Immune Functions ◽  
Transgenic Expression ◽  
Beneficial Microbes ◽  
Domain Specific ◽  
Pathogenic Microbes

AbstractPlants have evolved mechanisms to attract beneficial microbes and insects while protecting themselves against pathogenic microbes and pests. In Arabidopsis, the immune regulator PAD4 functions with its cognate partner EDS1 to limit pathogen growth. PAD4, independently of EDS1, reduces infestation by Green Peach Aphid (GPA). How PAD4 regulates these defense outputs is unclear. By expressing the N-terminal PAD4-lipase-like domain (LLD) without its C-terminal ‘EDS1-PAD4’ (EP) domain, we interrogated PAD4 functions in plant defense. Here we show that transgenic expression of PAD4LLD in Arabidopsis is sufficient for limiting GPA infestation, but not for conferring basal and effector-triggered pathogen immunity. This suggests that the C-terminal PAD4-EP domain is necessary for EDS1-dependent immune functions. Moreover, PAD4LLD is not sufficient to interact with EDS1, indicating the PAD4-EP domain is required for heterodimerisation. These data provide molecular evidence that PAD4 has domain specific functions.

scholarly journals The Arabidopsis PAD4 Lipase-Like Domain Is Sufficient for Resistance to Green Peach Aphid

2020 ◽  
Vol 33 (2) ◽  
pp. 328-335 ◽  
Author(s):  
Joram A. Dongus ◽  
Deepak D. Bhandari ◽  
Monika Patel ◽  
Lani Archer ◽  
Lucas Dijkgraaf ◽  
...  
Keyword(s):  
Plant Defense ◽  
Insect Pests ◽  
Green Peach Aphid ◽  
Aphid Resistance ◽  
Molecular Evidence ◽  
Immune Functions ◽  
Transgenic Expression ◽  
Domain Specific ◽  
Pathogenic Microbes

Plants have evolved mechanisms to protect themselves against pathogenic microbes and insect pests. In Arabidopsis, the immune regulator PAD4 functions with its cognate partner EDS1 to limit pathogen growth. PAD4, independently of EDS1, reduces infestation by green peach aphid (GPA). How PAD4 regulates these defense outputs is unclear. By expressing the N-terminal PAD4 lipase-like domain (PAD4LLD) without its C-terminal EDS1-PAD4 (EP) domain, we interrogated PAD4 functions in plant defense. Here, we show that transgenic expression of PAD4LLD in Arabidopsis is sufficient for limiting GPA infestation but not for conferring basal and effector-triggered pathogen immunity. This suggests that the C-terminal PAD4 EP domain is necessary for EDS1-dependent immune functions but is dispensable for aphid resistance. Moreover, PAD4LLD is not sufficient to interact with EDS1, indicating the PAD4-EP domain is required for stable heterodimerization. These data provide molecular evidence that PAD4 has domain-specific functions.

scholarly journals Microbial Toxins in Insect and Nematode Pest Biocontrol

2021 ◽  
Vol 22 (14) ◽  
pp. 7657
Author(s):  
Subbaiah Chalivendra
Keyword(s):  
Environmental Safety ◽  
Control Measures ◽  
Biocidal Activity ◽  
Transgenic Expression ◽  
Direct Injury ◽  
Pathogenic Microbes ◽  
Synthetic Pesticides ◽  
Invertebrate Pests ◽  
Livestock Diseases ◽  
Microbial Toxins

Invertebrate pests, such as insects and nematodes, not only cause or transmit human and livestock diseases but also impose serious crop losses by direct injury as well as vectoring pathogenic microbes. The damage is global but greater in developing countries, where human health and food security are more at risk. Although synthetic pesticides have been in use, biological control measures offer advantages via their biodegradability, environmental safety and precise targeting. This is amply demonstrated by the successful and widespread use of Bacillusthuringiensis to control mosquitos and many plant pests, the latter by the transgenic expression of insecticidal proteins from B. thuringiensis in crop plants. Here, I discuss the prospects of using bacterial and fungal toxins for pest control, including the molecular basis of their biocidal activity.

scholarly journals Root exudates mediate plant defense against foliar pathogens by recruiting beneficial microbes

2020 ◽  
Author(s):  
Tao Wen ◽  
Mengli Zhao ◽  
Jun Yuan ◽  
George A. Kowalchuk ◽  
Qirong Shen
Keyword(s):  
Plant Defense ◽  
Root Exudates ◽  
Beneficial Microbes ◽  
Foliar Pathogens

scholarly journals Broken Connections: The Evidence for Neuroglial Failure in ME/CFS

2021 ◽  
Author(s):  
Herbert Renz-Polster
Keyword(s):  
Functional Unit ◽  
Clinical Manifestations ◽  
Chronic Fatigue ◽  
Causal Chain ◽  
Immune Functions ◽  
Cellular Compartment ◽  
Fatigue Syndrome ◽  
Brain Connectome ◽  
The One ◽  
Regulatory Functions

In spite of decades of research, the pathobiology of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is still poorly understood. Several pathomechanisms have been identified, yet, it remains unclear how they are related and which of them may be upstream or downstream.. In this paper, we present a theoretical strategy that may help clarify the causal chain of pathophysiological events in ME/CFS. We propose to focus on the common final histological pathway of ME/CFS and suggest to ask: Which cellular compartment may explain the pathological processes and clinical manifestations observed in ME/CFS? Any functional unit consistently identified through this search may then be a plausible candidate for further exploration.For this "histological" approach we have compiled a list of 22 undisputed clinical and pathophysiological features of ME/CFS that need to be plausibly and most directly explained by the dysfunctional cellular unit in question. For each feature we have searched the literature for pathophysiological explanations and analyzed if they may point to the same functional cellular unit.Through this search we have identified the CNS neuroglia - microglia and astroglia - as the one functional unit in the human body which may best explain all and any of the clinical and pathological features, dysfunctions and observations described for ME/CFS. While this points to neuroinflammation as the central hub in ME/CFS, it also points to a novel understanding of the neuroimmune basis of ME/CFS. After all, the neuroglial cells are now understood as the functional matrix of the human brain connectome which operates beyond and above specific brain centers, receptor units or neurotransmitter systems and integrates innate immune functions with CNS regulatory functions pertaining to autonomous regulation, cellular metabolism and the stress response.

scholarly journals Disentangling cause and consequence: Genetic dissection of the DANGEROUS MIX2 risk locus, and activation of the DM2h NLR in autoimmunity

2020 ◽  
Author(s):  
Jana Ordon ◽  
Patrick Martin ◽  
Jessica Lee Erickson ◽  
Filiz Ferik ◽  
Gerd Balcke ◽  
...  
Keyword(s):  
Single Gene ◽  
Gene Clusters ◽  
Pathogen Resistance ◽  
Effector Proteins ◽  
Genetic Dissection ◽  
Immune Functions ◽  
Pathogenic Microbes ◽  
Risk Locus ◽  
Necessary And Sufficient ◽  
Intracellular Detection

AbstractNucleotide-binding domain–leucine-rich repeat-type immune receptors (NLRs) protect plants against pathogenic microbes through intracellular detection of effector proteins. However, this comes at a cost, as NLRs can also induce detrimental autoimmunity in genetic interactions with foreign alleles. This may occur when independently evolved genomes are combined in inter- or intraspecific crosses, or when foreign alleles are introduced by mutagenesis or transgenesis. Most autoimmunity-inducing NLRs are encoded within highly variable NLR gene clusters with no known immune functions, which were termed autoimmune risk loci. Whether risk NLRs differ from sensor NLRs operating in natural pathogen resistance and how risk NLRs are activated in autoimmunity is unknown. Here, we analyzed the DANGEROUS MIX2 risk locus, a major autoimmunity hotspot in Arabidopsis thaliana. By gene editing and heterologous expression, we show that a single gene, DM2h, is necessary and sufficient for autoimmune induction in three independent cases of autoimmunity in accession Landsberg erecta. We focus on autoimmunity provoked by an EDS1-YFPNLS fusion protein to functionally characterize DM2h and determine features of EDS1-YFPNLS activating the immune receptor. Our data suggest that risk NLRs function reminiscent of sensor NLRs, while autoimmunity-inducing properties of EDS1-YFPNLS are in this context unrelated to the protein’s functions as immune regulator. We propose that autoimmunity may, at least in some cases, be caused by spurious, stochastic interactions of foreign alleles with co-incidentally matching risk NLRs.

scholarly journals Disruption of Ethylene Responses by Turnip mosaic virus Mediates Suppression of Plant Defense against the Green Peach Aphid Vector

2015 ◽  
Vol 169 (1) ◽  
pp. 209-218 ◽  
Author(s):  
Clare L. Casteel ◽  
Manori De Alwis ◽  
Aurélie Bak ◽  
Haili Dong ◽  
Steven A. Whitham ◽  
...  
Keyword(s):  
Plant Defense ◽  
Mosaic Virus ◽  
Green Peach Aphid ◽  
Turnip Mosaic Virus ◽  
Aphid Vector

scholarly journals Vertically transmitted microbiome protects eggs from fungal infection and egg failure

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
M. E. Bunker ◽  
G. Elliott ◽  
H. Heyer-Gray ◽  
M. O. Martin ◽  
A. E. Arnold ◽  
...  
Keyword(s):  
Parental Care ◽  
Fungal Colonization ◽  
Vertical Transfer ◽  
Beneficial Microbes ◽  
Pathogenic Microbes ◽  
Hatch Success ◽  
Egg Failure ◽  
Pass Through ◽  
Sceloporus Virgatus ◽  
Behavioral Mechanisms

Abstract Background Beneficial microbes can be vertically transmitted from mother to offspring in many organisms. In oviparous animals, bacterial transfer to eggs may improve egg success by inhibiting fungal attachment and infection from pathogenic microbes in the nest environment. Vertical transfer of these egg-protective bacteria may be facilitated through behavioral mechanisms such as egg-tending, but many species do not provide parental care. Thus, an important mechanism of vertical transfer may be the passage of the egg through the maternal cloaca during oviposition itself. In this study, we examined how oviposition affects eggshell microbial communities, fungal attachment, hatch success, and offspring phenotype in the striped plateau lizard, Sceloporus virgatus, a species with no post-oviposition parental care. Results Relative to dissected eggs that did not pass through the cloaca, oviposited eggs had more bacteria and fewer fungal hyphae when examined with a scanning electron microscope. Using high throughput Illumina sequencing, we also found a difference in the bacterial communities of eggshells that did and did not pass through the cloaca, and the diversity of eggshell communities tended to correlate with maternal cloacal diversity only for oviposited eggs, and not for dissected eggs, indicating that vertical transmission of microbes is occurring. Further, we found that oviposited eggs had greater hatch success and led to larger offspring than those that were dissected. Conclusions Overall, our results indicate that female S. virgatus lizards transfer beneficial microbes from their cloaca onto their eggs during oviposition, and that these microbes reduce fungal colonization and infection of eggs during incubation and increase female fitness. Cloacal transfer of egg-protective bacteria may be common among oviparous species, and may be especially advantageous to species that lack parental care.

scholarly journals Even viruses can be beneficial microbes

2012 ◽  
Vol 33 (3) ◽  
pp. 111 ◽  
Author(s):  
Marilyn J Roossinck
Keyword(s):  
Food Sources ◽  
Beneficial Microbes ◽  
Microbial Eukaryotes ◽  
Pathogenic Microbes

Although viruses are almost always thought of as pathogens, most viruses probably do not cause disease, and some provide essential benefits to their hosts. Beneficial viruses are found in a wide variety of hosts including bacteria, insects, plants, fungi and other microbial eukaryotes, and humans and other animals. Beneficial viruses can confer tolerance to stress such as heat, cold and drought; they can prevent or attenuate infection by pathogenic microbes; they can act as bioweapons to allow their hosts access to new territory; and they have been critical in the evolution of their hosts. In spite of their bad reputation, viruses could be used to benefit humans and their food sources in novel ways.

scholarly journals Latent defense response to non-pathogenic microbial factors impairs plant-rhizobacteria mutualism

2020 ◽  
Author(s):  
Yu Yang ◽  
Shenglan Chen ◽  
Li Peng ◽  
Xiaomin Liu ◽  
Richa Kaushal ◽  
...  
Keyword(s):  
Plant Defense ◽  
Defense Response ◽  
Growth Promotion ◽  
Defense Responses ◽  
Plant Defense Responses ◽  
New Type ◽  
Pathogenic Microbes ◽  
Arabidopsis Mutant ◽  
Hidden Layer ◽  
Mutualistic Association

ABSTRACTUnlike pathogens that trigger plant defense responses, commensal or beneficial microbes are compatible with plants and do not elicit a defense response. An assumption underlying the compatibility is that plants are inert in mounting a defense response to non-pathogenic microbial factors. However, the mechanisms underlying this inertness in defense are unknown. Here a forward genetic screen led to the isolation of an Arabidopsis mutant displaying a new type of immunity which we named as latent defense response (LDR) to a beneficial rhizobacterium. The mutant, known as gp1 for Growth-Promotion 1, is impaired in rhizobacteria-induced plant growth-promotion due to disrupted oleic acid homeostasis and consequent activation of defense responses. Several bacterial volatile compounds trigger LDR in gp1 but not wild type plants. GP1 dysfunction strongly represses colonization of the beneficial rhizobacterium and alters root-associated microbiota. Our findings reveal a hidden layer of plant defense, LDR, which is suppressed by GP1 to allow mutualistic association between plants and beneficial rhizobacteria.One Sentence SummaryA hidden layer of host immunity against non-pathogenic microbes leads to plant incompatibility with beneficial rhizobacteria.

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