scholarly journals Dynamics and Endocytosis of Flot1 in Arabidopsis Require CPI1 Function

2020 ◽  
Vol 21 (5) ◽  
pp. 1552 ◽  
Author(s):  
Yangyang Cao ◽  
Qizouhong He ◽  
Zengxing Qi ◽  
Yan Zhang ◽  
Liang Lu ◽  
...  
Keyword(s):  
Plant Immunity ◽  
Critical Role ◽  
Defense Responses ◽  
Sterol Composition ◽  
Single Particle Tracking ◽  
Membrane Microdomains ◽  
Plant Defense Responses ◽  
Long Distance ◽  
Pathogen Invasion ◽  
Membrane Microdomain

Membrane microdomains are nano-scale domains (10–200 nm) enriched in sterols and sphingolipids. They have many important biological functions, including vesicle transport, endocytosis, and pathogen invasion. A previous study reported that the membrane microdomain-associated protein Flotillin1 (Flot1) was involved in plant development in Arabidopsis thaliana; however, whether sterols affect the plant immunity conveyed by Flot1 is unknown. Here, we showed that the root length in sterol-deficient cyclopropylsterol isomerase 1 (cpi1-1) mutants expressing Flot1 was significantly shorter than in control seedlings. The cotyledon epidermal cells in cpi1-1 mutants expressing Flot1 were smaller than in controls. Moreover, variable-angle total internal reflection fluorescence microscopy (VA-TIRFM) and single-particle tracking (SPT) analysis demonstrated that the long-distance Flot1-GFP movement was decreased significantly in cpi1-1 mutants compared with the control seedlings. Meanwhile, the value of the diffusion coefficient Ĝ was dramatically decreased in cpi1-1 mutants after flagelin22 (flg22) treatment compared with the control seedlings, indicating that sterols affect the lateral mobility of Flot1-GFP within the plasma membrane. Importantly, using confocal microscopy, we determined that the endocytosis of Flot1-GFP was decreased in cpi1-1 mutants, which was confirmed by fluorescence cross spectroscopy (FCS) analysis. Hence, these results demonstrate that sterol composition plays a critical role in the plant defense responses of Flot1.

scholarly journals Method for the Production and Purification of Plant Immuno-Active Xylanase from Trichoderma

2021 ◽  
Vol 22 (8) ◽  
pp. 4214
Author(s):  
Gautam Anand ◽  
Meirav Leibman-Markus ◽  
Dorin Elkabetz ◽  
Maya Bar
Keyword(s):  
Immune System ◽  
Plant Defense ◽  
Plant Immunity ◽  
Xylanase Activity ◽  
Hydrolytic Enzymes ◽  
Adaptive Immune System ◽  
Defense Responses ◽  
Plant Defense Responses ◽  
Xylanase Production ◽  
Ideal System

Plants lack a circulating adaptive immune system to protect themselves against pathogens. Therefore, they have evolved an innate immune system based upon complicated and efficient defense mechanisms, either constitutive or inducible. Plant defense responses are triggered by elicitors such as microbe-associated molecular patterns (MAMPs). These components are recognized by pattern recognition receptors (PRRs) which include plant cell surface receptors. Upon recognition, PRRs trigger pattern-triggered immunity (PTI). Ethylene Inducing Xylanase (EIX) is a fungal MAMP protein from the plant-growth-promoting fungi (PGPF)–Trichoderma. It elicits plant defense responses in tobacco (Nicotiana tabacum) and tomato (Solanum lycopersicum), making it an excellent tool in the studies of plant immunity. Xylanases such as EIX are hydrolytic enzymes that act on xylan in hemicellulose. There are two types of xylanases: the endo-1, 4-β-xylanases that hydrolyze within the xylan structure, and the β-d-xylosidases that hydrolyze the ends of the xylan chain. Xylanases are mainly synthesized by fungi and bacteria. Filamentous fungi produce xylanases in high amounts and secrete them in liquid cultures, making them an ideal system for xylanase purification. Here, we describe a method for cost- and yield-effective xylanase production from Trichoderma using wheat bran as a growth substrate. Xylanase produced by this method possessed xylanase activity and immunogenic activity, effectively inducing a hypersensitive response, ethylene biosynthesis, and ROS burst.

scholarly journals Two Arabidopsis Homologs of Human Lysine-Specific Demethylase Function in Epigenetic Regulation of Plant Defense Responses

2021 ◽  
Vol 12 ◽  
Author(s):  
Seong Woo Noh ◽  
Ri-Ra Seo ◽  
Hee Jin Park ◽  
Ho Won Jung
Keyword(s):  
Pseudomonas Syringae ◽  
Epigenetic Regulation ◽  
Plant Immunity ◽  
Systemic Disease ◽  
Defense Responses ◽  
Plant Defense Responses ◽  
Promoter Regions ◽  
Lysine Specific Demethylase ◽  
Genome Wide ◽  
Histone H3k4

Epigenetic marks such as covalent histone modification and DNA methylation are crucial for mitotically and meiotically inherited cellular memory-based plant immunity. However, the roles of individual players in the epigenetic regulation of plant immunity are not fully understood. Here we reveal the functions of two Arabidopsis thaliana homologs of human lysine-specific demethylase1-like1, LDL1 and LDL2, in the maintenance of methyl groups at lysine 4 of histone H3 and in plant immunity to Pseudomonas syringae infection. The growth of virulent P. syringae strains was reduced in ldl1 and ldl2 single mutants compared to wild-type plants. Local and systemic disease resistance responses, which coincided with the rapid, robust transcription of defense-related genes, were more stably expressed in ldl1 ldl2 double mutants than in the single mutants. At the nucleosome level, mono-methylated histone H3K4 accumulated in ldl1 ldl2 plants genome-wide and in the mainly promoter regions of the defense-related genes examined in this study. Furthermore, in silico comparative analysis of RNA-sequencing and chromatin immunoprecipitation data suggested that several WRKY transcription factors, e.g., WRKY22/40/70, might be partly responsible for the enhanced immunity of ldl1 ldl2. These findings suggest that LDL1 and LDL2 control the transcriptional sensitivity of a group of defense-related genes to establish a primed defense response in Arabidopsis.

scholarly journals Diversified Regulation of Cytokinin Levels and Signaling During Botrytis cinerea Infection in Arabidopsis

2021 ◽  
Vol 12 ◽  
Author(s):  
Beibei Li ◽  
Ruolin Wang ◽  
Shiya Wang ◽  
Jiang Zhang ◽  
Ling Chang
Keyword(s):  
Botrytis Cinerea ◽  
Response Regulator ◽  
Plant Immunity ◽  
Defense Responses ◽  
Cytokinin Oxidase ◽  
Plant Defense Responses ◽  
Necrotrophic Pathogen ◽  
Transcriptional Changes ◽  
Complex Regulation

Cytokinins (CKs) can modulate plant immunity to various pathogens, but how CKs are involved in plant defense responses to the necrotrophic pathogen Botrytis cinerea is still unknown. Here, we found that B. cinerea infection induced transcriptional changes in multiple genes involved in the biosynthesis, degradation, and signaling of CKs, as well as their contents, in pathogen-infected Arabidopsis leaves. Among the CKs, the gene expression of CYTOKININ OXIDASE/DEHYDROGENASE 5 (CKX5) was remarkably induced in the local infected leaves and the distant leaves of the same plant without pathogen inoculation. Cis-zeatin (cZ) and its riboside (cZR) accumulated considerably in infected leaves, suggesting an important role of the cis-zeatin type of CKs in the plant response to B. cinerea. Cytokinin double-receptor mutants were more susceptible to B. cinerea infection, whereas an exogenous CK treatment enhanced the expression levels of defense-related genes and of jasmonic acid (JA) and ethylene (ET), but not salicylic acid (SA), resulting in higher resistance of Arabidopsis to B. cinerea. Investigation of CK responses to B. cinerea infection in the JA biosynthesis mutant, jar1-1, and ET-insensitive mutant, ein2-1, showed that CK signaling and levels of CKs, namely, those of isopentenyladenine (iP), isopentenyladenine riboside (iPR), and trans-zeatin (tZ), were enhanced in jar1-1-infected leaves. By contrast, reductions in iP, iPR, tZ, and tZ riboside (tZR) as well as cZR contents occurred in ein2-1-infected leaves, whose transcript levels of CK signaling genes were likewise differentially regulated. The Arabidopsis Response Regulator 5 (ARR5) gene was upregulated in infected leaves of ein2-1 whereas another type-A response regulator, ARR16, was significantly downregulated, suggesting the existence of a complex regulation of CK signaling via the ET pathway. Accumulation of the cis-zeatin type of CKs in B. cinerea-infected leaves depended on ET but not JA pathways. Collectively, our findings provide evidence that CK responds to B. cinerea infection in a variety of ways that are differently modulated by JA and ET pathways in Arabidopsis.

RIN13-mediated disease resistance depends on the SNC1–EDS1/PAD4 signaling pathway in Arabidopsis

2020 ◽  
Vol 71 (22) ◽  
pp. 7393-7404
Author(s):  
Xiaoxiao Liu ◽  
Hui Liu ◽  
Jingjing He ◽  
Siyuan Zhang ◽  
Hui Han ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Signaling Pathway ◽  
Constitutive Expression ◽  
Defense Responses ◽  
Nuclear Accumulation ◽  
Plant Defense Responses ◽  
High Accumulation ◽  
Interacting Protein ◽  
Pathogen Invasion ◽  
Pathogenesis Related

Abstract Plants have evolved an innate immune system to protect themselves from pathogen invasion with the help of intracellular nucleotide-binding leucine-rich repeat (NLR) receptors, though the mechanisms remain largely undefined. RIN13 (RPM1-interacting protein 13) was previously reported to enhance disease resistance, and suppress RPM1 (a CNL-type NLR)-mediated hypersensitive response in Arabidopsis via an as yet unknown mechanism. Here, we show that RIN13 is a nuclear-localized protein, and functions therein. Overexpression of RIN13 leads to autoimmunity with high accumulation of salicylic acid (SA), constitutive expression of pathogenesis-related genes, enhanced resistance to a virulent pathogen, and dwarfism. In addition, genetic and transcriptome analyses show that SA-dependent and SA-independent pathways are both required for RIN13-mediated disease resistance, with the EDS1/PAD4 complex as an integration point. RIN13-induced dwarfism was rescued completely by either the pad4-1 or the eds1-2 mutant but partially by snc1-r1, a mutant of the TNL gene SNC1, suggesting the involvement of EDS1/PAD4 and SNC1 in RIN13 functioning. Furthermore, transient expression assays indicated that RIN13 promotes the nuclear accumulation of PAD4. Collectively, our study uncovered a signaling pathway whereby SNC1 and EDS1/PAD4 act together to modulate RIN13-triggered plant defense responses.

scholarly journals Jasmonic Acid at the Crossroads of Plant Immunity and Pseudomonas syringae Virulence

2020 ◽  
Vol 21 (20) ◽  
pp. 7482
Author(s):  
Aarti Gupta ◽  
Mamta Bhardwaj ◽  
Lam-Son Phan Tran
Keyword(s):  
Jasmonic Acid ◽  
Plant Defense ◽  
Pseudomonas Syringae ◽  
Regulatory Networks ◽  
Genetic Manipulation ◽  
Plant Immunity ◽  
Stomatal Closure ◽  
Defense Responses ◽  
Plant Defense Responses ◽  
Callose Deposition

Sensing of pathogen infection by plants elicits early signals that are transduced to affect defense mechanisms, such as effective blockage of pathogen entry by regulation of stomatal closure, cuticle, or callose deposition, change in water potential, and resource acquisition among many others. Pathogens, on the other hand, interfere with plant physiology and protein functioning to counteract plant defense responses. In plants, hormonal homeostasis and signaling are tightly regulated; thus, the phytohormones are qualified as a major group of signaling molecules controlling the most widely tinkered regulatory networks of defense and counter-defense strategies. Notably, the phytohormone jasmonic acid mediates plant defense responses to a wide array of pathogens. In this review, we present the synopsis on the jasmonic acid metabolism and signaling, and the regulatory roles of this hormone in plant defense against the hemibiotrophic bacterial pathogen Pseudomonas syringae. We also elaborate on how this pathogen releases virulence factors and effectors to gain control over plant jasmonic acid signaling to effectively cause disease. The findings discussed in this review may lead to ideas for the development of crop cultivars with enhanced disease resistance by genetic manipulation.

scholarly journals Seaweed-Based Compounds and Products for Sustainable Protection against Plant Pathogens

Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 59
Author(s):  
Pushp Sheel Shukla ◽  
Tudor Borza ◽  
Alan T. Critchley ◽  
Balakrishnan Prithiviraj
Keyword(s):  
Plant Defense ◽  
Plant Pathogens ◽  
Systemic Acquired Resistance ◽  
Plant Immunity ◽  
Crop Protection ◽  
Defense Responses ◽  
Systemic Resistance ◽  
Environmental Damage ◽  
Plant Defense Responses ◽  
Seaweed Extracts

Sustainable agricultural practices increasingly demand novel, environmentally friendly compounds which induce plant immunity against pathogens. Stimulating plant immunity using seaweed extracts is a highly viable strategy, as these formulations contain many bio-elicitors (phyco-elicitors) which can significantly boost natural plant immunity. Certain bioactive elicitors present in a multitude of extracts of seaweeds (both commercially available and bench-scale laboratory formulations) activate pathogen-associated molecular patterns (PAMPs) due to their structural similarity (i.e., analogous structure) with pathogen-derived molecules. This is achieved via the priming and/or elicitation of the defense responses of the induced systemic resistance (ISR) and systemic acquired resistance (SAR) pathways. Knowledge accumulated over the past few decades is reviewed here, aiming to explain why certain seaweed-derived bioactives have such tremendous potential to elicit plant defense responses with considerable economic significance, particularly with increasing biotic stress impacts due to climate change and the concomitant move to sustainable agriculture and away from synthetic chemistry and environmental damage. Various extracts of seaweeds display remarkably different modes of action(s) which can manipulate the plant defense responses when applied. This review focuses on both the similarities and differences amongst the modes of actions of several different seaweed extracts, as well as their individual components. Novel biotechnological approaches for the development of new commercial products for crop protection, in a sustainable manner, are also suggested.

scholarly journals Pseudomonas syringae pv. tomato DC3000 Effector HopG1 is a multi-faceted protein that Triggers Necrotic Cell Death that is attenuated by the Nonhost Resistance 2B (AtNHR2B) Protein

2021 ◽  
Author(s):  
Catalina Rodriguez-Puerto ◽  
Rupak Chakraborty ◽  
Raksha Singh ◽  
Perla Rocha-Loyola ◽  
Clemencia M. Rojas
Keyword(s):  
Cell Death ◽  
Plant Defense ◽  
Pseudomonas Syringae ◽  
Plant Immunity ◽  
Defense Responses ◽  
Necrotic Cell Death ◽  
Plant Defense Responses ◽  
Necrotic Cell ◽  
Tomato Dc3000 ◽  
Type Iii

The plant pathogenic bacterium Pseudomonas syringae pv. tomato DC3000 (Pst DC3000) has become a paradigm in plant-bacteria interactions due to its ability to cause disease in the model plant Arabidopsis thaliana. Pst DC3000 uses the type III secretion system to deliver type III secreted effectors (T3SEs) directly into the plant cytoplasm. Pst DC3000 T3SEs contribute to pathogenicity by suppressing plant defense responses and targeting plant’s physiological processes. Although the complete repertoire of effectors encoded in the Pst DC3000 genome have been identified, the specific function for most of them remains to be elucidated. The mitochondrial-localized T3E HopG1, suppresses plant defense responses and promotes the development of disease symptoms. Here, we show that HopG1 triggers necrotic cell death that enables the growth of non-adapted pathogens. We further showed that HopG1 interacts with the plant immunity-related protein AtNHR2B and that AtNHR2B attenuates HopG1- virulence functions.

scholarly journals Symbiotic polydnavirus of a parasite manipulates caterpillar and plant immunity

2018 ◽  
Vol 115 (20) ◽  
pp. 5199-5204 ◽  
Author(s):  
Ching-Wen Tan ◽  
Michelle Peiffer ◽  
Kelli Hoover ◽  
Cristina Rosa ◽  
Flor E. Acevedo ◽  
...  
Keyword(s):  
Plant Defense ◽  
Helicoverpa Zea ◽  
Plant Defenses ◽  
Plant Immunity ◽  
Defense Responses ◽  
Plant Defense Responses ◽  
Egg Hatch ◽  
Symbiotic Relationships ◽  
Herbivore Interactions ◽  
Plant Herbivore

Obligate symbioses occur when organisms require symbiotic relationships to survive. Some parasitic wasps of caterpillars possess obligate mutualistic viruses called “polydnaviruses.” Along with eggs, wasps inject polydnavirus inside their caterpillar hosts where the hatching larvae develop inside the caterpillar. Polydnaviruses suppress the immune systems of their caterpillar hosts, which enables egg hatch and wasp larval development. It is unknown whether polydnaviruses also manipulate the salivary proteins of the caterpillar, which may affect the elicitation of plant defenses during feeding by the caterpillar. Here, we show that a polydnavirus of the parasitoid Microplitis croceipes, and not the parasitoid larva itself, drives the regulation of salivary enzymes of the caterpillar Helicoverpa zea that are known to elicit tomato plant-defense responses to herbivores. The polydnavirus suppresses glucose oxidase, which is a primary plant-defense elicitor in the saliva of the H. zea caterpillar. By suppressing plant defenses, the polydnavirus allows the caterpillar to grow at a faster rate, thus improving the host suitability for the parasitoid. Remarkably, polydnaviruses manipulate the phenotypes of the wasp, caterpillar, and host plant, demonstrating that polydnaviruses play far more prominent roles in shaping plant–herbivore interactions than ever considered.

scholarly journals Fusarium graminearum arabinanase (Arb93B) Enhances Wheat Head Blight Susceptibility by Suppressing Plant Immunity

2019 ◽  
Vol 32 (7) ◽  
pp. 888-898 ◽  
Author(s):  
Guixia Hao ◽  
Susan McCormick ◽  
Martha M. Vaughan ◽  
Todd A. Naumann ◽  
Hye-Seon Kim ◽  
...  
Keyword(s):  
Fusarium Graminearum ◽  
Cell Walls ◽  
Fluorescent Protein ◽  
Plant Immunity ◽  
Defense Responses ◽  
Plant Cell Walls ◽  
Plant Defense Responses ◽  
Wild Type ◽  
Head Blight ◽  
Green Fluorescent

Fusarium head blight (FHB) of wheat and barley caused by the fungus Fusarium graminearum reduces crop yield and contaminates grain with mycotoxins. In this study, we investigated two exo-1,5-α-L-arabinanases (Arb93A and Arb93B) secreted by F. graminearum and their effect on wheat head blight development. Arabinan is an important component of plant cell walls but it was not known whether these arabinanases play a role in FHB. Both ARB93A and ARB93B were induced during the early stages of infection. arb93A mutants did not exhibit a detectable change in ability to cause FHB, whereas arb93B mutants caused lower levels of FHB symptoms and deoxynivalenol contamination compared with the wild type. Furthermore, virulence and deoxynivalenol contamination were restored to wild-type levels in ARB93B complemented mutants. Fusion proteins of green fluorescent protein (GFP) with the predicted chloroplast peptide or the mature protein of Arb93B were not observed in the chloroplast. Reactive oxygen species (ROS) production was reduced in the infiltrated zones of Nicotiana benthamiana leaves expressing ARB93B-GFP. Coexpression of ARB93B-GFP and Bax in N. benthamiana leaves significantly suppressed Bax-programmed cell death. Our results indicate that Arb93B enhances plant disease susceptibility by suppressing ROS-associated plant defense responses.

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