Overexpression of NDR1 leads to pathogen resistance at elevated temperatures.

Abiotic and biotic environments influence a myriad of plant-related processes, including growth, development, and the establishment and maintenance of interaction(s) with microbes. In the case of the latter, elevated temperature has been shown to be a key factor that underpins host resistance and pathogen virulence. In this study, we elucidate a role for Arabidopsis NON-RACE-SPECIFIC DISEASE RESISTANCE1 (NDR1) by exploiting effector-triggered immunity to define the regulation of plant host immunity in response to both pathogen infection and elevated temperature. We generated time-series RNA sequencing data of WT Col-0, an NDR1 overexpression line, and ndr1 and ics1-2 mutant plants under elevated temperature. Not surprisingly, the NDR1-overexpression line showed genotype-specific gene expression changes related to defense response and immune system function. The results described herein support a role for NDR1 in maintaining cell signaling during simultaneous exposure to elevated temperature and avirulent pathogen stressors.

Effect of Guided Imagery Meditation During Laparoscopic Cholecystectomy on Reducing Anxiety: A Randomized Controlled Trial.

BACKGROUND: Up to 90% of patients still experience pain after abdominal surgery, which also affects their physical recovery and psychological anxiety. AIM: To evaluate the effects of guided imagery meditation on ameliorating anxiety, improving the quality of sleep, and relieving postoperative pain in patients after laparoscopic cholecystectomy surgery. METHOD: In the general surgical ward of a teaching hospital, patients were randomly assigned to usual care (n = 34) and guided imagery meditation intervention (n = 34) groups, using the method. The measuring outcomes included their anxiety score, quality of sleep, and pain control. RESULTS: In terms of the anxiety difference, the experimental group scored 0.42 (standard deviation [SD] = 0.97), while the control group scored 4.79 (SD = 7.56), which indicates a statistically significant difference (F = 8.04, p = .01, partial eta2 = 0.11). In terms of quality of sleep, the mean score of the experimental group was 2.67 (SD = 1.96), while the control group scored 7.55 (SD = 3.81), which indicates a significant difference (F = 39.99, p = .001, partial eta2 = 0.39). The mean of the degree of postoperative pain was 2.11 points (SD = 1.39), and the score of the control group was 4.00 points (SD = 1.62), which indicates a significant difference (p = .001). CONCLUSIONS: Guided imagery meditation is a simple, non-invasive, non-pharmacologic intervention measure. It can reduce anxiety and postoperative pain, and improve the quality of sleep. Thus, it should be promoted in clinical practice.

The Pseudomonas syringae Type III Effector HopG1 Induces Actin Remodeling to Promote Symptom Development and Susceptibility during Infection.

The plant cytoskeleton underpins the function of a multitude of cellular mechanisms, including those associated with developmental- and stress-associated signaling processes. In recent years, the actin cytoskeleton has been demonstrated to play a key role in plant immune signaling, including a recent demonstration that pathogens target actin filaments to block plant defense and immunity. Herein, we quantified spatial changes in host actin filament organization after infection with Pseudomonas syringae pv. tomato DC3000 (Pst DC3000), demonstrating that the type-III effector HopG1 is required for pathogen-induced changes to actin filament architecture and host disease symptom development during infection. Using a suite of pathogen effector deletion constructs, coupled with high-resolution microscopy, we found that deletion of hopG1 from Pst DC3000 resulted in a reduction in actin bundling and a concomitant increase in the density of filament arrays in Arabidopsis, both of which correlate with host disease symptom development. As a mechanism underpinning this activity, we further show that the HopG1 effector interacts with an Arabidopsis mitochondrial-localized kinesin motor protein. Kinesin mutant plants show reduced disease symptoms after pathogen infection, which can be complemented by actin-modifying agents. In total, our results support a model in which HopG1 induces changes in the organization of the actin cytoskeleton as part of its virulence function in promoting disease symptom development.

Patterns of plant subcellular responses to successful oomycete infections reveal differences in host cell reprogramming and endocytic trafficking.

Adapted filamentous pathogens such as the oomycetes Hyaloperonospora arabidopsidis (Hpa) and Phytophthora infestans (Pi) project specialized hyphae, the haustoria, inside living host cells for the suppression of host defence and acquisition of nutrients. Accommodation of haustoria requires reorganization of the host cell and the biogenesis of a novel host cell membrane, the extrahaustorial membrane (EHM), which envelops the haustorium separating the host cell from the pathogen. Here, we applied live-cell imaging of fluorescent-tagged proteins labelling a variety of membrane compartments and investigated the subcellular changes associated with accommodating oomycete haustoria in Arabidopsis and N. benthamiana. Plasma membrane-resident proteins differentially localized to the EHM. Likewise, secretory vesicles and endosomal compartments surrounded Hpa and Pi haustoria revealing differences between these two oomycetes, and suggesting a role for vesicle trafficking pathways for the pathogen-controlled biogenesis of the EHM. The latter is supported by enhanced susceptibility of mutants in endosome-mediated trafficking regulators. These observations point at host subcellular defences and specialization of the EHM in a pathogen-specific manner. Defence-associated haustorial encasements, a double-layered membrane that grows around mature haustoria, were frequently observed in Hpa interactions. Intriguingly, all tested plant proteins accumulated at Hpa haustorial encasements suggesting the general recruitment of default vesicle trafficking pathways to defend pathogen access. Altogether, our results show common requirements of subcellular changes associated with oomycete biotrophy, and highlight differences between two oomycete pathogens in reprogramming host cell vesicle trafficking for haustoria accommodation. This provides a framework for further dissection of the pathogen-triggered reprogramming of host subcellular changes.

The Lifecycle of the Plant Immune System.

Throughout their life span, plants confront an endless barrage of pathogens and pests. To successfully defend against biotic threats, plants have evolved a complex immune system responsible for surveillance, perception, and the activation of defense. Plant immunity requires multiple signaling processes, the outcome of which vary according to the lifestyle of the invading pathogen(s). In short, these processes require the activation of host perception, the regulation of numerous signaling cascades, and transcriptome reprograming, all of which are highly dynamic in terms of temporal and spatial scales. At the same time, the development of a single immune event is subjective to the development of plant immune system, which is co-regulated by numerous processes, including plant ontogenesis and the host microbiome. In total, insight into each of these processes provides a fuller understanding of the mechanisms that govern plant-pathogen interactions. In this review, we will discuss the "lifecycle" of plant immunity: the development of individual events of defense, including both local and distal processes, as well as the development and regulation of the overall immune system by ontogenesis regulatory genes and environmental microbiota. In total, we will integrate the output of recent discoveries and theories, together with several hypothetical models, to present a dynamic portrait of plant immunity.

Arabidopsis calcium-dependent protein kinase 3 regulates actin cytoskeleton organization and immunity.

Pattern-triggered immunity and effector-triggered immunity are two primary forms of innate immunity in land plants. The molecular components and connecting nodes of pattern-triggered immunity and effector-triggered immunity are not fully understood. Here, we report that the Arabidopsis calcium-dependent protein kinase CPK3 is a key regulator of both pattern-triggered immunity and effector-triggered immunity. In vitro and in vivo phosphorylation assays, coupled with genetic and cell biology-based analyses, show that actin-depolymerization factor 4 (ADF4) is a physiological substrate of CPK3, and that phosphorylation of ADF4 by CPK3 governs actin cytoskeletal organization associated with pattern-triggered immunity. CPK3 regulates stomatal closure induced by flg22 and is required for resistance to Pst DC3000. Our data further demonstrates that CPK3 is required for resistance to Pst DC3000 carrying the effector AvrPphB. These results suggest that CPK3 is a missing link between cytoskeleton organization, pattern-triggered immunity and effector-triggered immunity.

Maternal immunization with a recombinant adenovirus-expressing fusion protein protects neonatal cotton rats from respiratory syncytia virus infection by transferring antibodies via breast milk and placenta.

We evaluated the efficacy of a recombinant adenovirus that expresses a membrane-truncated respiratory syncytial virus (RSV) fusion protein (Ad-F0ΔTM) in newborns via maternal immunization (MI) of pregnant cotton rats. Intranasal Ad-F0ΔTM immunization was given to pregnant female rats, and MI-newborn rats were then challenged intranasally with RSV. Anti-RSV IgGs were observed in the serum of MI-newborn rats after birth. The pulmonary viral loads in Ad-F0ΔTM vs. control vector, Ad-LacZ, and MI-newborns on day 3 post-challenge were reduced by 4 log10/g lung. The neutralizing antibody remained for up to 3 weeks in the serum of MI-newborns, which is when weaning began. Ad-F0ΔTM protected MI-newborns from RSV challenge for 1 week. Vertical-transferred protective antibodies were examined in the breast milk and placenta as well. Finally, anti-RSV immunity was not boosted but was only primed during the next RSV exposure in Ad-F0ΔTM-MI-newborns. Maternal Ad-F0ΔTM immunization provides acute protection against RSV infection in neonates.

Author Correction: Mutations in VP1 and 5'-UTR affect enterovirus 71 virulence.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Mutations in VP1 and 5'-UTR affect enterovirus 71 virulence.

Enterovirus 71 (EV71) is a major cause of hand, foot and mouth disease (HFMD). The current EV71 propagating in Vero (EV-V) or sub-passaged in RD (EV-R) cells was used as a pathogen. Interestingly, EV-R exhibited differential virulence; challenging human scavenger receptor class B2-expressing (hSCARB2-Tg) mice with EV71 revealed that EV-V was more virulent than EV-R: 100% of mice that received lethal amounts of EV-V died, while all the mice that received EV-R survived. Severe pathogenesis correlated with viral burdens and proinflammatory cytokine levels were observed in EV-V-challenged mice, but controversy in EV-R-challenged mice. Consensus sequence analysis revealed EV-R rapidly acquired complete mutations at E145G and S241L and partial mutations at V146I of VP1, and acquired a T to C substitution at nucleotide 494 of the 5'-UTR. EV-R exhibited higher binding affinity for another EV71 receptor, human P-selectin glycoprotein ligand-1 (hPSGL-1), than EV-V. Both EV71s exhibited no significant difference in binding to hSCARB2. The molecular modelling indicate that these mutations might influence EV71 engagement with PSGL-1 and in vivo virulence.

The MAP4 Kinase SIK1 Ensures Robust Extracellular ROS Burst and Antibacterial Immunity in Plants.

Microbial patterns are recognized by cell-surface receptors to initiate pattern-triggered immunity (PTI) in plants. Receptor-like cytoplasmic kinases (RLCKs), such as BIK1, and calcium-dependent protein kinases (CPKs) are engaged during PTI to activate the NADPH oxidase RBOHD for reactive oxygen species (ROS) production. It is unknown whether protein kinases besides CPKs and RLCKs participate in RBOHD regulation. We screened mutants in all ten Arabidopsis MAP4 kinases (MAP4Ks) and identified the conserved MAP4K SIK1 as a positive regulator of PTI. sik1 mutants were compromised in their ability to elicit the ROS burst in response to microbial features and exhibited compromised PTI to bacterial infection. SIK1 directly interacts with, phosphorylates, and stabilizes BIK1 in a kinase activity-dependent manner. Furthermore, SIK1 directly interacts with and phosphorylates RBOHD upon flagellin perception. Thus, SIK1 positively regulates immunity by stabilizing BIK1 and activating RBOHD to promote the extracellular ROS burst.

Quantitative Evaluation of Plant Actin Cytoskeletal Organization During Immune Signaling.

High spatial and temporal resolution microscopy-based methods are valuable tools for the precise real-time imaging of changes in cellular organization in response to stimulus perception. Here, we describe a quantitative method for the evaluation of the plant actin cytoskeleton during immune stimulus perception and the activation of defense signaling. As a measure of the biotic stress-induced changes in actin filament organization, we present methods for analyzing changes in actin filament organization following elicitation of pattern-triggered immunity and effector-triggered immunity. Using these methods, it is possible to not only quantitatively evaluate changes in actin cytoskeletal organization following biotic stress perception, but to also use these protocols to assess changes in actin filament organization following perception of a wide range of stimuli, including abiotic and developmental cues. As described herein, we present an example application of this method, designed to evaluate changes in actin cytoskeletal organization following pathogen perception and immune signaling.

Synthesis of Substituted Benzenes via Bi(OTf)3-Mediated Intramolecular Carbonyl Allylation of α-Prenyl or α-Geranyl ß-Arylketosulfones.

Intramolecular carbonyl allylation of α-prenyl or α-geranyl ß-arylketosulfones 5 in the presence of molecule sieves (MS) affords substituted benzenes 6-7 in moderate to good yields. The facile transformation proceeds by a synthetic sequence starting with the α-prenylation or α-geranylation of 1 and the Bi(OTf)3-mediated annulation of 5 followed by a sequential desulfonative aromatization or then an intramolecular Friedel-Crafts alkylation. A plausible mechanism has been studied and proposed.

Bi(OTf)3-mediated cycloisomerization of γ-alkynyl arylketones: application to the synthesis of substituted furans.

A novel Bi(OTf)3-mediated cycloisomerization of γ-alkynyl arylketones 4, 7, or 10 with molecular sieve (MS) in MeNO2 affords 3-substituted furans 3, 8, or 11 at rt for 3 h in moderate to good yields. The method provides mild, less-toxic, atom-economic and efficient conditions. The mechanism has been studied and proposed. Moreover, this route can be enlarged to gram scale.

One-pot access to sulfonylmethyl arylpyrroles via the domino aerobic Wacker-type aminocyclization/1,4-sulfonyl migration.

PdCl2/CuCl2/NH4OAc-mediated the domino aerobic Wacker-type aminocyclization of α-allyl-ß-ketosulfones 4 in cosolvents THF and MeOH afforded 2-(sulfonylmethyl)arylpyrroles 5 via 1,4-sulfonyl migration with moderate to good yields.