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Objective To identify the risk factors for severe diverticular bleeding in an elderly population. Methods Using a comprehensive computerized hospital database, severe and non-severe diverticular bleeding cases were compared for 19 factors: the age, sex, body mass index, comorbid conditions (hypertension, cardiovascular disease, cerebrovascular disease, and chronic renal failure, including those undergoing dialysis), history of diverticular bleeding, use of low-dose aspirin, use of antiplatelet agent besides aspirin, use of anticoagulant agent, use of prednisolone, use of non-steroidal anti-inflammatory drugs, use of cyclooxygenase-2 selective inhibitors, changes in vital signs, hypoalbuminemia, bilateral diverticula, identification of bleeding lesion, and rebleeding. Severe bleeding was defined as the need for blood transfusion, emergency surgery, or vascular embolization. Patients A total of 258 patients were admitted for lower gastrointestinal bleeding between August 2010 and July 2020, among whom 120 patients over 65 years old diagnosed with diverticular bleeding were included in this study. Results Fifty-one patients (43%) had severe diverticular bleeding. Independent risk factors for severe diverticular bleeding were as follows: change in vital signs [odds ratio (OR), 5.23; 95% confidence interval (CI), 1.9-14.4; p=0.0014], hypoalbuminemia (OR, 12.3; 95% CI, 1.97-77.3; p=0.0073), bilateral diverticula (OR, 3.47; 95% CI, 1.33-9.02; p=0.011), and rebleeding (OR, 5.92; 95% CI, 2.21-15.8; p0.001). The area under the receiver operating characteristic curve was 0.79 after cross validation. Conclusion Severe diverticular bleeding in elderly population may be predicted by changes in their vital signs, hypoalbuminemia, bilateral diverticula, and rebleeding.

Early detection of causal pathogens is important to prevent crop loss from diseases. However, some diseases, e.g., soilborne diseases, are difficult to diagnose due to the absence of visible or characteristic symptoms. In the present study, the use of the Oxford Nanopore MinION sequencer as a molecular diagnostic tool was assessed due to its long-read sequencing capabilities and portability. Nucleotide samples (DNA or RNA) from potato field soils were sequenced and analyzed using a locally curated pathogen database, followed by identification via sequence mapping. We performed computational speed tests against three commonly used mapping/annotation tools (BLAST, BWA-BLAST, and BWA-GraphMap) and found BWA-GraphMap to be the fastest tool for local searching against our curated pathogen database. The data collected demonstrate the high potential of Nanopore sequencing as a minimally biased diagnostic tool for comprehensive pathogen detection in soil from potato fields. Our GraphMap-based MinION sequencing method could be useful as a predictive approach for disease management by identifying pathogens present in field soil prior to planting. Although this method still needs more experimentation with a larger sample size for practical use, the data analysis pipeline presented can be applied to other cropping systems and diagnostics for detecting multiple pathogens.

The role of small secreted peptides in plant defense responses to viruses has seldom been investigated. Here, we report a role for potato (Solanum tuberosum) PIP1, a gene predicted to encode a member of the pathogen-associated molecular pattern (PAMP)-induced peptide (PIP) family, in the response of potato to Potato virus Y (PVY) infection. We show that exogenous application of synthetic StPIP1 to potato leaves and nodes increased the production of reactive oxygen species and the expression of plant defense-related genes, revealing that StPIP1 triggers early defense responses. In support of this hypothesis, transgenic potato plants that constitutively overexpress StPIP1 had higher levels of leaf callose deposition and, based on measurements of viral RNA titers, were less susceptible to infection by a compatible PVY strain. Interestingly, systemic infection of StPIP1-overexpressing lines with PVY resulted in clear rugose mosaic symptoms that were absent or very mild in infected non-transgenic plants. A transcriptomics analysis revealed that marker genes associated with both pattern-triggered immunity and effector-triggered immunity were induced in infected StPIP1 overexpressors but not in non-transgenic plants. Together, our results reveal a role for StPIP1 in eliciting plant defense responses and in regulating plant antiviral immunity.

Calcium (Ca2+) signaling in plant cells is an essential and early event during plant-microbe interactions. The recognition of microbe-derived molecules activates Ca2+ channels or Ca2+ pumps that trigger a transient increase in Ca2+ in the cytoplasm. The Ca2+ binding proteins (such as CBL, CPK, CaM, and CML), known as Ca2+ sensors, relay the Ca2+ signal into down-stream signaling events, e.g., activating transcription factors in the nucleus. For example, CaM and CML decode the Ca2+ signals to the CaM/CML-binding protein, especially CaM-binding transcription factors (AtSRs/CAMTAs), to induce the expressions of immune-related genes. In this review, we discuss the recent breakthroughs in down-stream Ca2+ signaling as a dynamic process, subjected to continuous variation and gradual change. AtSR1/CAMTA3 is a CaM-mediated transcription factor that represses plant immunity in non-stressful environments. Stress-triggered Ca2+ spikes impact the Ca2+-CaM-AtSR1 complex to control plant immune response. We also discuss other regulatory mechanisms in which Ca2+ signaling activates CPKs and MAPKs cascades followed by regulating the function of AtSR1 by changing its stability, phosphorylation status, and subcellular localization during plant defense.

Second messengers are cellular chemicals that act as "language codes", allowing cells to pass outside information to the cell interior. The cells then respond through triggering downstream reactions, including transcriptional reprograming to affect appropriate adaptive responses. The spatiotemporal patterning of these stimuli-induced signal changes has been referred to as a "signature", which is detected, decoded, and transmitted to elicit these downstream cellular responses. Recent studies have suggested that dynamic changes in second messengers, such as calcium (Ca2+), reactive oxygen species (ROS), and nitric oxide (NO), serve as signatures for both intracellular signaling and cell-to-cell communications. These second messenger signatures work in concert with physical signal signatures (such as electrical and hydraulic waves) to create a "lock and key" mechanism that triggers appropriate response to highly varied stresses. In plants, detailed information of how these signatures deploy their downstream signaling networks remains to be elucidated. Recent evidence suggests a mutual interplay between Ca2+ and ROS signaling has important implications for fine-tuning cellular signaling networks in plant immunity. These two signaling mechanisms amplify each other and this interaction may be a critical element of their roles in information processing for plant defense responses.

This study constructed a simplified post-endoscopic submucosal dissection (ESD) prediction model with a prognostic nutritional index (PNI). A total of 449 patients who underwent gastric ESD was included, divided with a ratio of 2:1, and assigned to the model or validation cohort. A prediction model of post-ESD (modified BEST-J score) was constructed using the model cohort. The modified BEST-J score was evaluated by comparing its accuracy to the BEST-J score in the validation cohort. Within 4 weeks of ESD, melena, hematemesis, or a 2 g/dL or greater decrease in hemoglobin level that required esophagogastroduodenoscopy was defined as post-ESD bleeding. In the model cohort, 299 patients were enrolled and 25 (8.4%) had post-ESD bleeding. Independent risk factors for post-ESD bleeding were use of P2Y12RA, tumor size > 30 mm, location of lesion at lower one-third of the stomach, and PNI ≤ 47.9. Constructing the modified BEST-J score based on these variables, the sensitivity, specificity, and positive likelihood ratio were 73.9%, 78.1%, and 3.37. When comparing the modified BEST-J score to the BEST-J score in the validation cohort, no significant difference was observed by ROC-AUC (0.77 vs. 0.75, p = 0.81). Modified BEST-J score can predict post-ESD bleeding more simply, with the same accuracy as the BEST-J score.

Danger signals trigger immune responses upon perception by a complex surveillance system. Such signals can originate from the infectious nonself or the damaged self, the latter termed damage-associated molecular patterns (DAMPs). Here, we apply Matzinger's danger model to plant innate immunity to discuss the adaptive advantages of DAMPs and their integration into preexisting signaling pathways. Constitutive DAMPs (cDAMPs), e.g., extracellular ATP, histones, and self-DNA, fulfill primary, conserved functions and adopt a signaling role only when cellular damage causes their fragmentation or localization to aberrant compartments. By contrast, immunomodulatory peptides (also known as phytocytokines) exclusively function as signals and, upon damage, are activated as inducible DAMPs (iDAMPs). Dynamic coevolutionary processes between the signals and their emerging receptors and shared co-receptors have likely linked danger recognition to preexisting, conserved downstream pathways.

Calcium (Ca2+ ) signaling regulates salicylic acid (SA)-mediated immune response through calmodulin-meditated transcriptional activators, AtSRs/CAMTAs, but its mechanism is not fully understood. Here, we report an AtSR1/CAMTA3-mediated regulatory mechanism involving the expression of the SA receptor, NPR1. Results indicate that the transcriptional expression of NPR1 was regulated by AtSR1 binding to a CGCG box in the NPR1 promotor. The atsr1 mutant exhibited resistance to the virulent strain of Pseudomonas syringae pv. tomato (Pst), however it was susceptible to an avirulent Pst strain carrying avrRpt2, due to the failure of the induction of hypersensitive responses. These resistant/susceptible phenotypes in the atsr1 mutant were reversed in the npr1 mutant background, suggesting that AtSR1 regulates NPR1 as a downstream target during plant immune response. The virulent Pst strain triggered a transient elevation in intracellular Ca2+ concentration, whereas the avirulent Pst strain triggered a prolonged change. The distinct Ca2+ signatures were decoded into the regulation of NPR1 expression through AtSR1's IQ motif binding with Ca2+ -free-CaM2, while AtSR1's calmodulin-binding domain with Ca2+ -bound-CaM2. These observations reveal a role for AtSR1 as a Ca2+ -mediated transcription regulator in controlling the NPR1-mediated plant immune response. This article is protected by copyright. All rights reserved.

Plants encrypt the perception of different pathogenic stimuli into specific intracellular calcium (Ca2+) signatures and subsequently decrypt the signatures into appropriate downstream responses through various Ca2+ sensors. Two microbe-associated molecular patterns (MAMPs), bacterial flg22 and fungal chitin, and one damage-associated molecular pattern (DAMP), AtPep1, were used to study the differential Ca2+ signatures in Arabidopsis leaves. The results revealed that flg22, chitin, and AtPep1 induced distinct changes in Ca2+ dynamics in both the cytosol and nucleus. In addition, Flg22 and chitin upregulated the expression of salicylic acid-related genes, ICS1 and EDS1, whereas AtPep1 upregulated the expression of jasmonic acid-related genes, JAZ1 and PDF1.2, in addition to ICS1 and EDS1. These data demonstrated that distinct Ca2+ signatures caused by different molecular patterns in leaf cells lead to specific downstream events. Furthermore, these changes in the expression of defense-related genes were disrupted in a knockout mutant of the AtSR1/CAMTA3 gene, encoding a calmodulin-binding transcription factor, in which a calmodulin-binding domain on AtSR1 was required for deciphering the Ca2+ signatures into downstream transcription events. These observations extend our knowledge regarding unique and intrinsic roles for Ca2+ signaling in launching and fine-tuning plant immune response, which are mediated by the AtSR1/CAMTA3 transcription factor.

ATP is not only an essential metabolite of cellular biochemistry but also acts as a signal in the extracellular milieu. In plants, extracellular ATP is monitored by the purinergic receptor P2K1. Recent studies have revealed that extracellular ATP acts as a damage-associated molecular pattern in plants, and its signaling through P2K1 is important for mounting an effective defense response against various pathogenic microorganisms. Biotrophic and necrotrophic pathogens attack plants using different strategies, to which plants respond accordingly with salicylate-based or jasmonate/ethylene-based defensive signaling, respectively. Interestingly, defense mediated by P2K1 is effective against pathogens of both lifestyles, raising the question of the level of interplay between extracellular ATP signaling and that of jasmonate, ethylene, and salicylate. To address this issue, we analyzed ATP-induced transcriptomes in wild-type Arabidopsis (Arabidopsis thaliana) seedlings and mutant seedlings defective in essential components in the signaling pathways of jasmonate, ethylene, and salicylate (classic defense hormones) as well as a mutant and an overexpression line of the P2K1 receptor. We found that P2K1 function is crucial for faithful ATP-induced transcriptional changes and that a subset of genes is more responsive in the P2K1 overexpression line. We also found that more than half of the ATP-responsive genes required signaling by one or more of the pathways for the classical defense hormones, with the jasmonate-based signaling being more critical than others. By contrast, the other ATP-responsive genes were unaffected by deficiencies in signaling for any of the classical defense hormones. These ATP-responsive genes were highly enriched for defense-related Gene Ontology terms. We further tested the ATP-induced genes in knockout mutants of transcription factors, demonstrating that MYCs acting downstream of the jasmonate receptor complex and calmodulin-binding transcription activators are nuclear transducers of P2K1-mediated extracellular ATP signaling.

Calcium (Ca2+) acts as an essential second messenger connecting the perception of microbe signals to the establishment of appropriate immune and symbiotic responses in plants. Accumulating evidence suggests that plants distinguish different microorganisms through plasma membrane-localized pattern recognition receptors. The particular recognition events are encoded into Ca2+ signatures, which are sensed by diverse intracellular Ca2+ binding proteins. The Ca2+ signatures are eventually decoded to distinct downstream responses through transcriptional reprogramming of the defense or symbiosis-related genes. Recent observations further reveal that Ca2+-mediated signaling is also involved in negative regulation of plant immunity. This review is intended as an overview of Ca2+ signaling during immunity and symbiosis, including Ca2+ responses in the nucleus and cytosol.

The defense gene activations that provide non-host disease resistance in plants are signaled by various elicitors. A number of the fungal-derived signal such as chitosan and DNase are uniquely able to promote transcription through direct effects on the DNA of pea chromatin at sites of defense gene transcription. Other biological signals are contained within the reactive oxygen species (ROS) and make substantial changes in DNA in other tissues. The current research probes the ROS elicitor concentrations and the conditions within pea endocarp nuclear material temporally associated with the activation of pathogenesis-related (PR) genes. Within 10 min, ROS accumulate in response to a bean pathogen Fusarium solani f.sp. phaseoli (Fsph) to levels 4-fold those elicited by the pea pathogen Fusarium solani f.sp. pisi (Fspi). Application of Hydrogen peroxide (H 2 O 2 ) (HP) increases DNA fragmentation and activates the PR genes ( DRR206, defensin, PR10, and PR1b ) within 50 min and changes the nuclear diameters of the pea host cells in 3 h. Increased levels of the phytoalexin, pisatin and the growth suppression of the pea pathogen, Fspi, were observed within 24 h after H 2 O 2 treatment to the endocarp. Our results suggest that H 2 O 2 contributes to the induction of the defense response in pea endocarp tissue, which is likely mediated by activation of DNA damage responses.

Plant recognition of invading organisms occurs through identification of foreign molecules associated with attackers and of self-derived, damage-associated molecules. Perception of these molecules activates signaling processes including dynamic changes in ion balance, production of second messengers such as reactive oxygen species and nitric oxide, increased levels of plant hormones, and map kinase cascade activation. Together these signaling events stimulate transcriptional changes to initiate plant defense responses. Among the earliest detectable signaling events is a rapid increase in apoplastic pH, i.e., extracellular alkalinization. Here, an assay for quantification of this alkalinization response using suspension-cultured cell lines for Arabidopsis, potato, and maize is described. This assay is an inexpensive, fast, simple, and reproducible method to quantify defense signaling output, providing a powerful tool for evaluating early plant responses to elicitors and pathogens. Results from the alkalinization assay are comparable to other more costly and time-consuming methods for assessing defense signaling, such as measurement of the oxidative burst, calcium influx, and marker gene expression. This bioassay is a quantitative and robust method for evaluation of plant defense output. © 2017 by John Wiley & Sons, Inc.

The first layer of plant immunity is deployed by recognition of pathogen-associated molecule patterns (PAMPs) and induction of early stress responses. Flagellin is the major protein component of the flagellum. Flagellin-derived peptide fragments such as Flg22, a short active peptide derived from the highly conserved part of the N-terminal region, are recognized as PAMPs by a specific perception system present in most higher plants. Some bacteria evade the plant recognition system by altering the Flg22 region in the flagellin. Instead, a small subset of plants (i.e., solanaceous plants) can sense these bacteria by recognizing a second region, termed FlgII-28. The function of FlgII-28 has been well-documented in tomato but not in potato plants. Here, we investigated the effect of FlgII-28 on several defense responses in potato. Cytosolic calcium (Ca2+) elevation is an early defense response upon pathogenic infection. We generated transgenic potato plants expressing aequorin, a nontoxic Ca2+-activated photoprotein. The results showed that FlgII-28 induced strong cytosolic Ca2+ elevation in a dose-dependent manner, whereas the response was attenuated when a Ca2+ channel blocker was added. In addition, the FlgII-28-triggered cytosolic Ca2+ elevation was shown to subsequently promote extracellular alkalinization, reactive oxygen species production, mitogen-activated protein kinase phosphorylation, and transcriptional reprogramming of defense-related genes in potato. Interestingly, all tested defense responses caused by FlgII-28 were significantly stronger than those caused by Flg22, suggesting that FlgII-28 acts as a primary flagellar PAMP to elicit multiple defense responses in potato.

Extracellular ATP is perceived by the purinoceptor P2K1, leading to induction of defense response in plants. Previously, we described the transcriptomic response to extracellular ATP in wild-type Arabidopsis seedlings and mutants of classical defense hormone signaling pathways (Jewell et al., 2019, Plant Physiol. 179: 1144-58), in which extracellular ATP was found to induce defense-related genes independently and also along with other defense signaling pathways. In the present study, we provide further analysis and discussion of the data that we neglected to describe in the previous transcriptomics report. Briefly, we describe transcriptomic differences between a P2K1 knockout mutant (dorn1) and wild-type seedlings in the absence of exogenous ATP as well as an analysis of genes more responsive to extracellular ATP in a P2K1 overexpression line. Finally, we describe an exaggerated response to extracellular ATP in the ein2 mutant and suggest testable explanations of this phenomenon.

Extracellular ATP functions as an important signaling molecule in both plants and animals. In plants, ATP is released in the extracellular region of cells in response to environmental perturbations, such as herbivory, cellular damage, or other abiotic and biotic stimuli, which is then perceived by the purinoceptor P2K1 as a damaged-self signal for activation of defense responses. Given its involvement in various physiological processes, quantification of extracellular ATP is important for further understanding of its molecular function. In this chapter, we describe a method for the accurate and reliable determination of extracellular ATP concentrations in plant cell culture media based on the luciferase-luciferin reaction, using either end-point or real-time detection assays. The protocol can be easily performed with any luminometer within 1 h after sample collection. Although we use Arabidopsis suspension cells, the protocol described can be optimized for any cell type.

Background: Although antithrombotic agents are widely used for cardiac and cerebrovascular disease prevention, they increase the risk of gastrointestinal (GI) bleeding. Objective: To examine GI bleeding risk in association with an esophagogastroduodenoscopy (EGD) biopsy performed in patients without cessation of antithrombotic therapy. Methods: This study was prospectively conducted at 14 centers. EGD biopsies were performed in patients receiving antithrombotic agents without cessation, as well as age- and sex-matched controls not receiving antithrombotic therapy. Patients treated with warfarin before the biopsy had a prothrombin time-international normalized ratio level

Extracellular ATP functions as an important signaling molecule in both plants and animals. In plants, ATP is released in the extracellular region of cells in response to environmental perturbations, such as herbivory, cellular damage, or other abiotic and biotic stimuli, which is then perceived by the purinoceptor P2K1 as a damaged-self signal for activation of defense responses. Given its involvement in various physiological processes, quantification of extracellular ATP is important for further understanding of its molecular function. In this chapter, we describe a method for the accurate and reliable determination of extracellular ATP concentrations in plant cell culture media based on the luciferase-luciferin reaction, using either end-point or real-time detection assays. The protocol can be easily performed with any luminometer within 1 h after sample collection. Although we use Arabidopsis suspension cells, the protocol described can be optimized for any cell type.

Intraductal papillary mucinous neoplasms (IPMNs) occasionally form a fistula to adjacent organs, resulting in obstructive jaundice and cholangitis due to mucus obstruction. Although some procedures such as endoscopic nasobiliary drainage are attempted, they often do not work adequately because of high mucus viscosity. Herein, we report the case of an 87-year-old man with obstructive cholangitis treated by endoscopic septotomy and mucus suction with direct peroral cholangioscopy using conventional endoscopy. The patient incidentally showed a branched-type IPMN in the pancreatic head on computed tomography (CT) approximately 10-years ago. Although the patient's tumor had grown slowly and he occasionally developed cholangitis, he did not want surgery. He was admitted to our hospital because of cholangitis by mucus obstruction with a PB fistula. Endoscopic retrograde cholangiopancreatography (ERCP) and septotomy were performed. Septotomy made the duodenal papilla a large orifice, thereby facilitating spontaneous drainage of mucus. In addition, conventional endoscopy with a large working channel enabled direct access into the orifice and smooth mucus suction, thereby alleviating his cholangitis. In conclusion, septotomy and direct peroral cholangioscopy using conventional endoscopy could be useful to control biliary tract infection and obstructive jaundice due to mucus obstruction from an IPMNs with PB fistula.

Abdominal ultrasonography revealed a low echoic mass in the upper abdomen of a 65-year-old man. He was referred to our department, where abdominal CT revealed a tumor with a 30-mm contrast effect on the distal side of the inferior part of the duodenum. Endoscopy revealed a submucosal tumor in the same region, and ultrasonic endoscopy showed a low echoic mass with a clear boundary derived from the muscle layer. The duodenum was partially resected based on a diagnosis of suspected gastrointestinal stromal tumors (GIST), and the skin tumor was simultaneously resected. An elastic, soft, 30-mm tumor mass was found in the upper duodenum during surgery, and small nodules of 3-5mm were identified throughout the 110-cm length of the jejunum at intervals of 20-30cm. The histopathological diagnosis was GIST and immunostaining showed the mass to be c-kit and CD34 positive. We diagnosed the skin tumor as a neurofibroma (von Recklinghausen disease). Mutational analysis of c-kit in the resected specimen showed no mutation, therefore suggesting that imatinib would not be effective. Since the nodules remaining in the small intestine might also be GIST, we established a policy of regular imaging assessments.

Highlight Lipochitooligosaccharide (LCOs) are important molecules for plant-microbe symbiosis but can also serve as plant growth regulators. This study shows that LCO addition induces the expression of genes involved in root growth promotion in C4 grasses., Although lipo-chitooligosaccharides (LCOs) are important signal molecules for plant-symbiont interactions, a number of reports suggest that LCOs can directly impact plant growth and development, separate from any role in plant symbioses. In order to investigate this more closely, maize and Setaria seedlings were treated with LCO and their growth was evaluated. The data indicate that LCO treatment significantly enhanced root growth. RNA-seq transcriptomic analysis of LCO-treated maize roots identified a number of genes whose expression was significantly affected by the treatment. Among these genes, some LCO-up-regulated genes are likely involved in root growth promotion. Interestingly, some stress-related genes were down-regulated after LCO treatment, which might indicate reallocation of resources from defense responses to plant growth. The promoter activity of several LCO-up-regulated genes using a β-glucuronidase reporter system was further analysed. The results showed that the promoters were activated by LCO treatment. The data indicate that LCO can directly impact maize root growth and gene expression.

On-site diagnosis of plant diseases can be a useful tool for growers for timely decisions enabling the earlier implementation of disease management strategies that reduce the impact of the disease. Presently in many diagnostic laboratories, the polymerase chain reaction (PCR), particularly real-time PCR, is considered the most sensitive and accurate method for plant pathogen detection. However, laboratory-based PCRs typically require expensive laboratory equipment and skilled personnel. In this study, soil-borne pathogens of potato are used to demonstrate the potential for on-site molecular detection. This was achieved using a rapid and simple protocol comprising of magnetic bead-based nucleic acid extraction, portable real-time PCR (fluorogenic probe-based assay). The portable real-time PCR approach compared favorably with a laboratory-based system, detecting as few as 100 copies of DNA from Spongospora subterranea. The portable real-time PCR method developed here can serve as an alternative to laboratory-based approaches and a useful on-site tool for pathogen diagnosis.

Damage-associated molecular patterns (DAMPs), such as extracellular ATP, act as danger signals in response to biotic and abiotic stresses. Extracellular ATP is perceived by a plant purinoceptor, P2 receptor kinase 1 (P2K1), inducing downstream signaling for defense responses. How ATP induces these defense responses has not been well studied. A recent study by Tripathi et al. (Plant Physiology, 176: 511-523, 2018) revealed a synergistic interaction between extracellular ATP and jasmonate (JA) signaling during plant defense responses. This signaling crosstalk requires the formation of secondary messengers, i.e., cytosolic calcium, reactive oxygen species, and nitric oxide. This finding has given a new direction towards understanding the defense signals activated by DAMPs. In this addendum, we discuss possible insights into how extracellular ATP signaling interacts with the JA signaling pathway for plant defense responses.

ATP, the universal energy currency of all organisms, is released into the extracellular matrix and serves as a signal among cells, where it is referred to as an extracellular ATP. Although a signalling role for extracellular ATP has been well studied in mammals over the last 40 years, investigations of such a role in plants are at an early stage. Recently, the first plant receptor for extracellular ATP, DOes not Respond to Nucleotides (DORN1), was identified in Arabidopsis thaliana by mutant screening. DORN1 encodes a legume-type lectin receptor kinase that is structurally distinct from the mammalian extracellular ATP receptors. In the present review, we highlight the genetic and biochemical evidence for the role of DORN1 in extracellular ATP signalling, placing this within the wider context of extracellular ATP signalling during plant stress responses.

After the severe accident at the Fukushima-1 nuclear power plant, large amounts of contaminated stagnant water have accumulated in turbine buildings and their surroundings. This rapid communication...

Because of their sessile nature, plants have developed a number of sophisticated signaling systems to adapt to environmental changes. Previous research has shown that extracellular ATP is an important signaling molecule used by plants and functions in a variety of processes, including growth, development, and stress responses. Recently, DORN1 was identified as the first plant purinoceptor, essential for the plant response to ATP. The identification of the receptor is a milestone for our overall understanding of various physiological events regulated by extracellular ATP. In this review, we will discuss the possible roles of DORN1 providing future direction for research into the role of extracellular ATP in plants.

To characterize the rubble and trees contaminated by radionuclides released by the recent accident at the Fukushima Daiichi Nuclear Power Station, the radiochemical analysis protocols were modified...