Plant pathogenic bacterium Ralstonia solanacearum can rapidly evolve tolerance to antimicrobials produced by Pseudomonas biocontrol bacteria.

Soil-borne plant pathogens significantly threaten crop production due to lack of effective control methods. One alternative to traditional agrochemicals is microbial biocontrol, where pathogen growth is suppressed by naturally occurring bacteria that produce antimicrobial chemicals. However, it is still unclear if pathogenic bacteria can evolve tolerance to biocontrol antimicrobials and if this could constrain the long-term efficacy of biocontrol strategies. Here we used an in vitro experimental evolution approach to investigate if the phytopathogenic Ralstonia solanacearum bacterium, which causes bacterial wilt disease, can evolve tolerance to antimicrobials produced by Pseudomonas bacteria. We further asked if tolerance was specific to pairs of R. solanacearum and Pseudomonas strains and certain antimicrobial compounds produced by Pseudomonas. We found that while all R. solanacearum strains could initially be inhibited by Pseudomonas strains, this inhibition decreased following successive subculturing with or without Pseudomonas supernatants. Using separate tolerance assays, we show that the majority of R. solanacearum strains evolved increased tolerance to multiple Pseudomonas strains. Mechanistically, evolved tolerance was most likely linked to reduced susceptibility to orfamide lipopeptide antimicrobials secreted by Pseudomonas strains in our experimental conditions. Some levels of tolerance also evolved in the control treatments, which was likely correlated response due to adaptations to the culture media. Together, these results suggest that plant-pathogenic bacteria can rapidly evolve increased tolerance to bacterial antimicrobial compounds, which could reduce the long-term efficacy of microbial biocontrol. [Abstract copyright: © The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Evolutionary Biology.

Nitric oxide sensing in plants is mediated by proteolytic control of group VII ERF transcription factors

Nitric oxide (NO) is an important signaling compound in prokaryotes and eukaryotes. In plants, NO regulates critical developmental transitions and stress responses. Here, we identify a mechanism for NO sensing that coordinates responses throughout development based on targeted degradation of plant-specific transcriptional regulators, the group VII ethylene response factors (ERFs). We show that the N-end rule pathway of targeted proteolysis targets these proteins for destruction in the presence of NO, and we establish them as critical regulators of diverse NO-regulated processes, including seed germination, stomatal closure, and hypocotyl elongation. Furthermore, we define the molecular mechanism for NO control of germination and crosstalk with abscisic acid (ABA) signaling through ERF-regulated expression of ABSCISIC ACID INSENSITIVE5 (ABI5). Our work demonstrates how NO sensing is integrated across multiple physiological processes by direct modulation of transcription factor stability and identifies group VII ERFs as central hubs for the perception of gaseous signals in plants

Expression profiling during arabidopsis/downy mildew interaction reveals a highly-expressed effector that attenuates responses to salicylic acid

Plants have evolved strong innate immunity mechanisms, but successful pathogens evade or suppress plant immunity via effectors delivered into the plant cell. Hyaloperonospora arabidopsidis (Hpa) causes downy mildew on Arabidopsis thaliana, and a genome sequence is available for isolate Emoy2. Here, we exploit the availability of genome sequences for Hpa and Arabidopsis to measure gene-expression changes in both Hpa and Arabidopsis simultaneously during infection. Using a high-throughput cDNA tag sequencing method, we reveal expression patterns of Hpa predicted effectors and Arabidopsis genes in compatible and incompatible interactions, and promoter elements associated with Hpa genes expressed during infection. By resequencing Hpa isolate Waco9, we found it evades Arabidopsis resistance gene RPP1 through deletion of the cognate recognized effector ATR1. Arabidopsis salicylic acid (SA)-responsive genes including PR1 were activated not only at early time points in the incompatible interaction but also at late time points in the compatible interaction. By histochemical analysis, we found that Hpa suppresses SA-inducible PR1 expression, specifically in the haustoriated cells into which host-translocated effectors are delivered, but not in non-haustoriated adjacent cells. Finally, we found a highly-expressed Hpa effector candidate that suppresses responsiveness to SA. As this approach can be easily applied to host-pathogen interactions for which both host and pathogen genome sequences are available, this work opens the door towards transcriptome studies in infection biology that should help unravel pathogen infection strategies and the mechanisms by which host defense responses are overcome

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Combining in vitro and in vivo screening to identify efficient Pseudomonas biocontrol strains against the phytopathogenic bacterium Ralstonia solanacearum

Although plant pathogens are traditionally controlled using synthetic agrochemicals, the availability of commercial bactericides is still limited. One potential control strategy could be the use of plant growth-promoting bacteria (PGPB) to suppress pathogens via resource competition or the production of antimicrobial compounds. This study aimed to conduct in vitro and in vivo screening of eight Pseudomonas strains against Ralstonia solanacearum (the causative agent of bacterial wilt) and to investigate underlying mechanisms of potential pathogen suppression. We found that inhibitory effects were Pseudomonas strain-specific, with strain CHA0 showing the highest pathogen suppression. Genomic screening identified 2,4-diacetylphloroglucinol, pyoluteorin, and orfamides A and B secondary metabolite clusters in the genomes of the most inhibitory strains, which were investigated further. Although all these compounds suppressed R. solanacearum growth, only orfamide A was produced in the growth media based on mass spectrometry. Moreover, orfamide variants extracted from Pseudomonas cultures showed high pathogen suppression. Using the “Micro-Tom” tomato cultivar, it was found that CHA0 could reduce bacterial wilt disease incidence with one of the two tested pathogen strains. Together, these findings suggest that a better understanding of Pseudomonas–Ralstonia interactions in the rhizosphere is required to successfully translate in vitro findings into agricultural applications

RESEARCH ARTICLES 1 A Panel Study on the Effects of Social Media Use and Internet Connectedness on Academic Performance and Social Support 17 Smartphone Use, Addiction, Narcissism, and Personality: A Mixed Methods Investigation 33 Therapy on the Move: The

ABSTRACT The current study examined the role of personality attributes and online profile characteristics as predictors of self-disclosure. The authors were specifically interested to learn how personality and profile attractiveness influenced the quantity and type of information individuals would be willing to share about themselves with a potential dating partner who they have never met before. The results of the online survey with 149 female participants revealed that the propensity to trust and extraversion were significant positive predictors of self-reported tendency to self-disclose potentially sensitive and identifying information, while greater profile attractiveness further increased the amount of information they were willing to share. These findings suggest that information disclosure is in part driven by personality and context, which has potential implications for how careful individuals are about revealing potentially sensitive information to strangers

Metalation calculators for E. coli strain JM109 (DE3): Aerobic, anaerobic and hydrogen peroxide exposed cells cultured in LB media

Three Web-based calculators, and three analogous spreadsheets, have been generated that predict in vivo metal occupancies of proteins based on known metal affinities. The calculations exploit estimates of the availabilities of the labile buffered pools of different metals inside a cell. Here, metal availabilities have been estimated for a strain of Escherichia coli that is commonly used in molecular biology and biochemistry research, e.g. in the production of recombinant proteins. Metal availabilities have been examined for cells grown in Luria-Bertani (LB) medium aerobically, anaerobically, and in response to H2O2 by monitoring the abundance of a selected set of metal-responsive transcripts by quantitative polymerase chain reaction (qPCR). The selected genes are regulated by DNA-binding metal sensors that have been thermodynamically characterized in related bacterial cells enabling gene expression to be read out as a function of intracellular metal availabilities expressed as free energies for forming metal complexes. The calculators compare these values with the free energies for forming complexes with the protein of interest, derived from metal affinities, to estimate how effectively the protein can compete with exchangeable binding sites in the intracellular milieu. The calculators then inter-compete the different metals, limiting total occupancy of the site to a maximum stoichiometry of 1, to output percentage occupancies with each metal. In addition to making these new and conditional calculators available, an original purpose of this article was to provide a tutorial that discusses constraints of this approach and presents ways in which such calculators might be exploited in basic and applied research, and in next-generation manufacturing

Burden and centralised treatment in Europe of rare tumours: results of RARECAREnet - a population-based study

Background Rare cancers pose challenges for diagnosis, treatments, and clinical decision making. Information about rare cancers is scant. The RARECARE project defined rare cancers as those with an annual incidence of less than six per 100 000 people in European Union (EU). We updated the estimates of the burden of rare cancers in Europe, their time trends in incidence and survival, and provide information about centralisation of treatments in seven European countries. Methods We analysed data from 94 cancer registries for more than 2 million rare cancer diagnoses, to estimate European incidence and survival in 2000–07 and the corresponding time trends during 1995–2007. Incidence was calculated as the number of new cases divided by the corresponding total person-years in the population. 5-year relative survival was calculated by the Ederer-2 method. Seven registries (Belgium, Bulgaria, Finland, Ireland, the Netherlands, Slovenia, and the Navarra region in Spain) provided additional data for hospitals treating about 220 000 cases diagnosed in 2000–07. We also calculated hospital volume admission as the number of treatments provided by each hospital rare cancer group sharing the same referral pattern. Findings Rare cancers accounted for 24% of all cancers diagnosed in the EU during 2000–07. The overall incidence rose annually by 0.5% (99·8% CI 0·3–0·8). 5-year relative survival for all rare cancers was 48·5% (95% CI 48·4 to 48·6), compared with 63·4% (95% CI 63·3 to 63·4) for all common cancers. 5-year relative survival increased (overall 2·9%, 95% CI 2·7 to 3·2), from 1999–2001 to 2007–09, and for most rare cancers, with the largest increases for haematological tumours and sarcomas. The amount of centralisation of rare cancer treatment varied widely between cancers and between countries. The Netherlands and Slovenia had the highest treatment volumes. Interpretation Our study benefits from the largest pool of population-based registries to estimate incidence and survival of about 200 rare cancers. Incidence trends can be explained by changes in known risk factors, improved diagnosis, and registration problems. Survival could be improved by early diagnosis, new treatments, and improved case management. The centralisation of treatment could be improved in the seven European countries we studied. Funding The European Commission (Chafea)