Genetic Mapping, Candidate Gene Identification and Marker Validation for Host Plant Resistance to the Race 4 of Fusarium oxysporum f. sp. cubense Using Musa acuminata ssp. malaccensis.

Fusarium wilt of banana is a devastating disease that has decimated banana production worldwide. Host resistance to Fusarium oxysporum f. sp. Cubense (Foc), the causal agent of this disease, is genetically dissected in this study using two Musa acuminata ssp. Malaccensis segregating populations, segregating for Foc Tropical (TR4) and Subtropical (STR4) race 4 resistance. Marker loci and trait association using 11 SNP-based PCR markers allowed the candidate region to be delimited to a 12.9 cM genetic interval corresponding to a 959 kb region on chromosome 3 of 'DH-Pahang' reference assembly v4. Within this region, there was a cluster of pattern recognition receptors, namely leucine-rich repeat ectodomain containing receptor-like protein kinases, cysteine-rich cell-wall-associated protein kinases, and leaf rust 10 disease-resistance locus receptor-like proteins, positioned in an interspersed arrangement. Their transcript levels were rapidly upregulated in the resistant progenies but not in the susceptible F2 progenies at the onset of infection. This suggests that one or several of these genes may control resistance at this locus. To confirm the segregation of single-gene resistance, we generated an inter-cross between the resistant parent 'Ma850' and a susceptible line 'Ma848', to show that the STR4 resistance co-segregated with marker '28820' at this locus. Finally, an informative SNP marker 29730 allowed the locus-specific resistance to be assessed in a collection of diploid and polyploid banana plants. Of the 60 lines screened, 22 lines were predicted to carry resistance at this locus, including lines known to be TR4-resistant, such as 'Pahang', 'SH-3362', 'SH-3217', 'Ma-ITC0250', and 'DH-Pahang/CIRAD 930'. Additional screening in the International Institute for Tropical Agriculture's collection suggests that the dominant allele is common among the elite 'Matooke' NARITA hybrids, as well as in other triploid or tetraploid hybrids derived from East African highland bananas. Fine mapping and candidate gene identification will allow characterization of molecular mechanisms underlying the TR4 resistance. The markers developed in this study can now aid the marker-assisted selection of TR4 resistance in breeding programs around the world.

The photolytic conversion of 4-nonylphenol to 4-nonylcatechol within snowpack of the Palisade Glacier, Sierra Nevada, CA, USA.

4-Nonylphenol (4-NP), an environmental pollutant with potent ecotoxicological effects, has been discovered in significant quantities in glacial ice and snow of the Sierra Nevada Mountain Range, CA. Photolysis of 4-NP is suspected to be a major, if not the sole, breakdown pathway in snow. However, the photolysis process has yet to be characterized in detail for this unique environment. This study therefore seeks to (1) confirm the presence of the major photolysis product within snowpack and snowmelt samples from the Palisade Glacier, CA, (2) determine key photolysis parameters through laboratory assays in snow analogs, and (3) compute environmentally relevant photolysis rates in snowpack via a spectral solar irradiance model parameterized for the Palisade Glacier. The primary photooxidation product of 4-NP, 4-nonylcatechol (4-NC), was synthesized and characterized by NMR and GC-MS for use as a reference standard in the detection of 4-NC in environmental samples. 4-NP was detected in all snowpack (n = 4) and snowmelt (n = 5) samples, with concentrations of 1.05 (± 0.11) µg L-1 and 1.28 (± 0.12) µg L-1, respectively. 4-NC was detected in all snowmelt outflow samples and all but one snow samples (88 % detection frequency) but was below the limit of quantification for the given method. All samples were collected during a sampling regime at the Palisade Glacier in August of 2021. Quantum yields of photolysis at the 277 nm absorption band were determined to be 0.36 (±0.06) and 0.21 (±0.06) in ultrapure water and liquid snow, respectively. Under clear sky conditions at the Palisade Glacier, half-lives for 4-NP are estimated to range from 235 to 251 h (9.8-10.5 days) based on assays conducted in liquid snowmelt and irradiance modeling. These results suggest that the photolysis of 4-NP, and hence the production of 4-NC, is occurring at significant rates within the snowpack where 4-NC is inevitably released to downstream catchment areas via snowmelt. 4-NC is significantly more toxic than its precursor, thereby raising amplified concerns for downstream human and wildlife populations. Furthermore, the ubiquity of 4-NP among the Earth's environments presents this as an issue of potentially global concern.

Identification of a Major QTL-Controlling Resistance to the Subtropical Race 4 of Fusarium oxysporum f. sp. cubense in Musa acuminata ssp. malaccensis.

Vascular wilt caused by the ascomycete fungal pathogen Fusarium oxysporum f. sp. cubense (Foc) is a major constraint of banana production around the world. The virulent race, namely Tropical Race 4, can infect all Cavendish-type banana plants and is now widespread across the globe, causing devastating losses to global banana production. In this study, we characterized Foc Subtropical Race 4 (STR4) resistance in a wild banana relative which, through estimated genome size and ancestry analysis, was confirmed to be Musa acuminata ssp. malaccensis. Using a self-derived F2 population segregating for STR4 resistance, quantitative trait loci sequencing (QTL-seq) was performed on bulks consisting of resistant and susceptible individuals. Changes in SNP index between the bulks revealed a major QTL located on the distal end of the long arm of chromosome 3. Multiple resistance genes are present in this region. Identification of chromosome regions conferring resistance to Foc can facilitate marker assisted selection in breeding programs and paves the way towards identifying genes underpinning resistance.

Effect of Toxic Phthalate-Based Plasticizer on the Biodegradability of Polyhydroxyalkanoate.

While new biodegradable materials are being rapidly introduced to address plastic pollution, their end-of-life impacts remain unclear. Biodegradable plastics typically comprise a biopolymer matrix with functional additives and/or solid fillers, which may be toxic. Here, using an established method for continuous biodegradation monitoring, we investigated the impact of a commonly used plasticizer, dibutyl phthalate (DBP), on the biodegradation of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) in soil. The presence of DBP delayed the initial stage of PHBV biodegradation but then accelerated subsequent rates of biodegradation. Furthermore, it led to significant increases in total bacterial and fungal biomass and altered the composition of microbial communities with significant increases in the relative abundances of Thauera (gammaproteobacterial) and Mucor circinelloides (fungal) populations. It is proposed, with evidence from biodegradation behavior and microbial analysis, that the presence of DBP likely stimulated a microbial community shift, introduced higher proportions of more readily degradable amorphous regions from the plasticizing effect, and facilitated access to the bulk polymer matrix for microorganisms or at least their associated enzymes. These effects in combination overcame the initial inhibition effect of the DBP and resulted in a net increase in the rate of biodegradation of PHBV.

Thermodynamics Affecting Glacier-Released 4-Nonylphenol Deposition in Alaska, USA.

Glaciers have recently been recognized as a secondary source of organic pollutants. As glacier melt rates increase, downstream ecosystems are at increasing risk of exposure to these pollutants. Nonylphenols (NPs) are well-documented anthropogenic persistent pollutants whose environmental prevalence and ecotoxicity make them of immediate concern to the health of humans and wildlife populations. As glacier melt increases, transport of NPs to downstream environments will also increase. Snow, ice, meltwater, and till for five glaciers in the Chugach National Forest and Kenai Fjords National Park, Alaska, USA, were investigated for the presence of 4-nonylphenol (4NP). Average concentrations for snow, ice, meltwater, and glacial till were 0.77 ± .017 µg/L snow water, 0.75 ± .006 µg/L, 0.26 ± .053 µg/L, and 0.016 ± .004 µg/g, respectively. All samples showed the presence of 4NP. Deposition of 4NP downstream from glaciers will depend more on the ionic strength of the water than organic carbon to drive partitioning and deposition. Laboratory studies of partition coefficients showed that ionic strength contributed 59% of the driving force behind partitioning, while organic carbon contributed 36%. Evidence was found for interaction between organic carbon and the aqueous phase. The 4NP Setschenow constants (Ks ) were determined for particle types with varying percentages of organic carbon. Values of Ks increased with the percentage of organic carbon. These relationships will shape further studies of 4NP deposition into the environment downstream of glacier outflow. Environ Toxicol Chem 2022;41:1623-1636. © The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

A physiotherapy triage service for orthopaedic upper limb service: an effective way to reduce clinic visits and identify patients for operative intervention.

INTRODUCTION: Waiting times for orthopaedic outpatient clinics are steadily increasing over the past number of years worldwide. Physiotherapy triage clinics are being utilised to improve access for patients with non-urgent or routine musculoskeletal disorders, to be seen in a timely manner in specialised out-patient clinics. Using these clinics, the aim is to ultimately stratify patients into appropriate management pathways. The aim of our study is to review the effectiveness of a physiotherapy triage clinic run by advanced practitioner physiotherapists (APP), who specialise in the review of upper limb referrals from primary care physicians. METHODS: For this study, a prospective, observational design was used. Patients were referred to the Department of Orthopaedic Surgery, Upper Limb Service at a national elective Orthopaedic Unit. The patients' referrals were reviewed and allocated to a physiotherapy triage pathway if deemed routine, non-urgent cases. After assessment in the APP clinic, the physiotherapist made recommendations and highlighted patients who required review or case discussion with an orthopaedic surgeon. The discharge rate and outcome of patients referred on for further interventions or operative procedures was followed over a 3-year period. The outcomes for the patients were reviewed, including whether patients who met an orthopaedic surgeon went on to have surgical intervention. RESULTS: During the study, 646 patients were reviewed in an upper limb APP physiotherapy triage clinic. Of those reviewed, only 201 patients required review by an orthopaedic surgeon. Of those, 56 patients were scheduled for an operative procedure. Within the 3-year period, 50 patients of those scheduled underwent the procedure. The most commonly performed procedure being an arthroscopic subacromial decompression with or without acromioplasty or rotator cuff repair. A total of 145 patients referred by the physiotherapist had a shoulder injection including subacromial and glenohumeral intra-articular injection. The initial discharge rate was 68%. CONCLUSIONS: There is a high initial discharge rate after initial assessment by APP triage clinics for upper limb musculoskeletal pathology. This is beneficial in alleviating waiting list pressures allowing only those patients in need of intervention to be placed on the ever expanding waiting lists to see orthopaedic surgeons. This study shows a high proportion of patients being offered surgical intervention after being referred by the APP. We conclude from this that the agreement between the physiotherapist's initial diagnosis and that of the consultant surgeon being similar in identifying patients who would benefit from operative intervention.

Feasibility of promoting physical activity using mHEALTH technology in rural women: the step-2-it study.

BACKGROUND: Rural women are more likely to be obese and have a higher risk for chronic disease than their non-rural counterparts. Inadequate physical activity (PA) at least in part contributes to this increased risk. Rural women face personal, social and environmental barriers to PA engagement. Interventions promoting walking among rural women have demonstrated success; however, few of these studies use text messaging to promote PA. METHODS: Step-2-It was a pilot study to assess the feasibility, acceptability, and effectiveness of text-messaging combined with a pedometer to promote PA, specifically walking among English-speaking women, aged 40 and older, living in a rural, northwest Illinois county. Enrolled participants completed baseline assessments, received pedometers and two types of automated text messages: motivational messages to encourage walking, and accountability messages to report pedometer steps. Participants engaged in 3, 6, 9, and 12-week follow-ups to download pedometer data, and completed post-intervention assessments at 12 weeks. RESULTS: Of the 44 enrolled participants, 35 participants (79.5%) completed the intervention. Among completers, the proportion meeting PA guidelines increased from 31.4% (11/35) at baseline to 48.6% (17/35) at post-intervention, those with no PA decreased from 20% (7/35) to 17.1% (6/35). During weeks 1-12, when participants received motivational text messages, average participant daily step count was 5926 ± 3590, and remained stable during the intervention. Pedometer readings were highly correlated with self-reported steps (r = 0.9703; p < 0.001). CONCLUSION: Step-2-It was a feasible and acceptable walking intervention for older rural women. Technology, including text messaging, should be investigated further as an enhancement to interventions for rural women. Trial Registration on Clinicaltrials.gov: NCT04812756, registered on March 22, 2021.

The development and validation of a novel LC-MS/MS method for the simultaneous quantification of Molnupiravir and its metabolite ß-d-N4-hydroxycytidine in human plasma and saliva.

In light of the recent global pandemic, Molnupiravir (MPV) or EIDD-2801, developed for the treatment of patients with uncomplicated influenza, is now being trialled for the treatment of infections caused by highly pathogenic coronaviruses, including COVID-19. A sensitive LC-MS/MS method was developed and validated for the simultaneous quantification of MPV and its metabolite ß-d-N4-hydroxycytidine (NHC) in human plasma and saliva. The analytes were extracted from the matrices by protein precipitation using acetonitrile. This was followed by drying and subsequently injecting the reconstituted solutions onto the column. Chromatographic separation was achieved using a polar Atlantis C18 column with gradient elution of 1 mM Ammonium acetate in water (pH4.3) and 1 mM Ammonium acetate in acetonitrile. Analyte detection was conducted in negative ionisation mode using SRM. Analysis was performed using stable isotopically labelled (SIL) internal standards (IS). The m/z transitions were: MPV (328.1→126.0), NHC (258.0→125.9) and MPV-SIL (331.0→129.0), NHC-SIL (260.9→128.9). Validation was over a linear range of 2.5-5000 ng/ml for both plasma and saliva. Across four different concentrations, precision and accuracy (intra- and inter-day) were 15%; and recovery of both analytes from plasma and saliva was between 95% and 100% and 65-86% respectively. Clinical pharmacokinetic studies are underway utilising this method for determination of MPV and its metabolite in patients with COVID-19 infection.

Environmental conditions affecting re-release from particulate matter of 4-Nonylphenol into an aqueous medium.

4-nonylphenol is a persistent organic pollutant with endocrine-disrupting properties. A nonpolar product of microbial degradation derived from the surfactant nonylphenol polyethoxylate, 4-nonylphenol is capable of long-range transport attached to particulates. Bioactive concentrations of 4-nonylphenol have been found in the surface water, soils, snow, and particulate matter of the Eastern Sierra Nevada Mountains (USA) hundreds of miles from their origins. As a result of particulate deposition, seasonal and glacial snow pack concentrations measured 20 to 100 times higher than in surface waters. Batch desorption assays were run on particulate matter dosed with 4-nonylphenol. Desorption was measured in 63 to 500 µm particles under 2 different temperature conditions with varying fractions of organic carbon in turbulent or undisturbed states. Lower temperatures (4 °C) decreased the mean percentage of 4-nonylphenol released from particulates in disturbed and undisturbed conditions, whereas the mean percentage of 4-nonylphenol released at 20 °C was reduced by agitation. The effect of agitation at 4 °C was not practically or statistically significant. Particulates with a higher percentage of organic carbon (75%) released very little of the bound 4-nonylphenol (0.53%) compared with particulates containing 4 to 5% of organic carbon that released up to 13%. Larger particles released the least amount of 4-nonylphenol, whereas smaller particles released the most amount. Water and sediment samples taken from below the Palisades Glacier in the Sierra Nevada Mountains showed the greatest 4-nonylphenol concentrations directly below the glacier, implying that glacial particulates will release adsorbed 4-nonylphenol. Environ Toxicol Chem 2019;38:350-360. © 2018 SETAC.

Periprosthetic hip fractures: A review of the economic burden based on length of stay.

INTRODUCTION: With the increasing rates of total hip replacements being performed worldwide, there is an increasing incidence of periprosthetic fractures. As our patients' demographics change to include older patients with multiple medical co-morbidities, there is a concurrent increase in morbidity and mortality rates. This leads to longer hospital stays and increasing hospital costs. In the current economic climate, the cost of treating periprosthetic fractures must be addressed and appropriate resource and funding allocation for future provision of services should be planned. MATERIALS AND METHODS: All periprosthetic hip fractures that were admitted to a single trauma unit over a three-year period were reviewed. Independent chart review, haematological and radiological review was undertaken. All patients with a periprosthetic fracture associated with a total hip arthroplasty or hemiarthroplasty were included. Follow up data including complications were collated. Data from the hospital inpatient database and finance department was utilized for cost analysis. All statistical analysis was preformed using Minitab version 17. RESULTS: 48 patients were identified who met the inclusion criteria for review. The majority of participants were female with a mean age of 73.5 years. The mean time to fracture was 4.5 years (9 months-18.5 years). Periprosthetic fracture was associated with total hip arthroplasty in 24 cases and a Vancouver B2 classification was most common at n = 20. The majority of patients had revision arthroplasty, with a mean length of stay of 24 days for the whole cohort (9-42). Vancouver B3 fractures had the longest inpatient stay at a mean of 26 days. The mean cost of for a full revision of stem with additional plate and cable fixation was over €27000 compared to €14,600 for ORIF and cable fixation based on length of hospital stay. CONCLUSION: The prolonged length of stay associated with Vancouver B2 and B3 fractures leads to increased costs to the healthcare service. Accurately calculating the costs of total treatment for periprosthetic fractures is difficult due to a lack of transparency around implant and staffing costs. However, as we can expect increasing incidence of periprosthetic fractures presenting in the coming years it is paramount that we make financial provisions within healthcare budgets to ensure we can treat these patients appropriately.

Food safety labelling of chicken to prevent campylobacteriosis: consumer expectations and current practices.

BACKGROUND: Campylobacter is the leading cause of bacterial gastroenteritis worldwide, and contaminated chicken is a significant vehicle for spread of the disease. This study aimed to assess consumers' knowledge of safe chicken handling practices and whether their expectations for food safety labelling of chicken are met, as a strategy to prevent campylobacteriosis. METHODS: We conducted a cross-sectional survey of 401 shoppers at supermarkets and butcheries in Wellington, New Zealand, and a systematic assessment of content and display features of chicken labels. RESULTS: While 89% of participants bought, prepared or cooked chicken, only 15% knew that most (60-90%) fresh chicken in New Zealand is contaminated by Campylobacter. Safety and correct preparation information on chicken labels, was rated 'very necessary' or 'essential' by the majority of respondents. Supermarket chicken labels scored poorly for the quality of their food safety information with an average of 1.7/5 (95% CI, 1.4-2.1) for content and 1.8/5 (95% CI, 1.6-2.0) for display. CONCLUSIONS: Most consumers are unaware of the level of Campylobacter contamination on fresh chicken and there is a significant but unmet consumer demand for information on safe chicken preparation on labels. Labels on fresh chicken products are a potentially valuable but underused tool for campylobacteriosis prevention in New Zealand.

Sprain of the Subaxial Cervical Spine in Childhood.

Posterior atlantoaxial ligament disruption in children is a rare diagnosis. We present a case of a young girl with cervical spine posterior atlantoaxial ligament disruption post a fall from a climbing frame. Presenting with minimal symptoms other than neck pain, this case highlights the diagnostic difficulty and need for further radiological imaging in paediatric patients with neck pain post trauma.

Assessing the public health impact of using poison center data for public health surveillance.

CONTEXT: The National Poison Data System (NPDS) is a database and surveillance system for US poison centers (PCs) call data. The Centers for Disease Control and Prevention (CDC) and American Association of Poison Control Centers (AAPCC) use NPDS to identify incidents of potential public health significance. State health departments are notified by CDC of incidents identified by NPDS to be of potential public health significance. Our objective was to describe the public health impact of CDC's notifications and the use of NPDS data for surveillance. METHODS: We described how NPDS data informed three public health responses: the Deepwater Horizon incident, national exposures to laundry detergent pods, and national exposures to e-cigarettes. Additionally, we extracted survey results of state epidemiologists regarding NPDS incident notification follow-up from 1 January 2015 to 31 December 2016 to assess current public health application of NPDS data using Epi Info 7.2 and analyzed data using SAS 9.3. We assessed whether state health departments were aware of incidents before notification, what actions were taken, and whether CDC notifications contributed to actions. DISCUSSION: NPDS data provided evidence for industry changes to improve laundry detergent pod containers safety and highlighted the need to regulate e-cigarette sale and manufacturing. NPDS data were used to improve situational awareness during the 2010 Deepwater Horizon oil spill. Of 59 health departments and PCs who responded to CDC notifications about anomalies (response rate = 49.2%), 27 (46%) reported no previous awareness of the incident, and 20 (34%) said that notifications contributed to public health action. CONCLUSIONS: Monitoring NPDS data for anomalies can identify emerging public health threats and provide evidence-based science to support public health action and policy changes.

Total Hip Replacement Revision in a Single Brand Small Cementless Stem - Our Experience after the Findings of the National Joint Registry.

BACKGROUND: Cementless total hip replacement is the common THR performed in England, Wales, Northern Ireland and the Isle of Man. The Corail stem is the most popular cementless implant and has a ODEP 10A rating. Review of its performance in the registry identified an increase rate of revision amongst the smaller stem sizes. However, clarity was not provided on the explanation for this finding. We reviewed our own experience of smaller stems with a view to understanding the reasons for revision. METHODS: We reviewed a single centre, single surgeon experience of the smaller Corail stem sizes for a ten-year period from 2003 to 2013. All data was collected from a prospectively maintained database. Details of clinical and radiological follow up were collected for all patients who had Corail stem size 8 and 9 implanted. Revision for any cause was taken as our endpoint. RESULTS: 542 patients underwent total hip arthroplasty using the Corail stem during the study period. 53 small size Corail stems were implanted. The average age was 59 (range 17-88 years) and the average follow up was 41.4 months (range 1-118 months). 6 patients underwent revision during the study period, but only 4 stems required revision. The reasons for revision were aseptic loosening, fracture and metal-on metal complications. Only two stems required revision for stem related factors (3.8%). CONCLUSION: There was no evidence of an increased rate of revision in the small Corail stems in our cohort.

Quantifying Intraoperative Workloads Across the Surgical Team Roles: Room for Better Balance?

BACKGROUND: Surgical performance, provider health, and patient safety can be compromised when workload demands exceed individual capability on the surgical team. The purpose of this study is to quantify and compare intraoperative workload among surgical team members. METHODS: Observations were conducted for an entire surgical day for 33 participating surgeons and their surgical team at one medical institution. Workload (mental, physical, case complexity, distractions, and case difficulty) was measured for each surgical team member using questions from validated questionnaires. Statistical analyses were performed with a mixed effects model. RESULTS: A total of 192 surgical team members participated in 78 operative cases, and 344 questionnaires were collected. Procedures with high surgeon mental and physical workload included endovascular and gastric surgeries, respectively. Ratings did not differ significantly among surgeons and residents, but scrub nurses physical demand ratings were 14-22 (out of 100) points lower than the surgeons, residents, and surgical assistants. Residents reported the highest mental workload, averaging 19-24 points higher than surgical assistants, scrub nurses, and circulating nurses. Mental and physical demands exceeded 50 points 28-45 % of the time for surgeons and residents. Workload did not differ between minimally invasive and open techniques. CONCLUSION: The workload questionnaires are an effective tool for quantifying intraoperative workload across the surgical team to ensure mental and physical demands do not exceed thresholds where performance may decrease and injury risk increase. This tool has the potential to measure the safety of current procedures and drive design of workload interventions.

The link between flowering time and stress tolerance.

Evolutionary success in plants is largely dependent on the successful transition from vegetative to reproductive growth. In the lifetime of a plant, flowering is not only an essential part of the reproductive process but also a critical developmental stage that can be vulnerable to environmental stresses. Exposure to stress during this period can cause substantial yield losses in seed-producing plants. However, it is becoming increasingly evident that altering flowering time is an evolutionary strategy adopted by plants to maximize the chances of reproduction under diverse stress conditions, ranging from pathogen infection to heat, salinity, and drought. Here, recent studies that have revealed new insights into how biotic and abiotic stress signals can be integrated into floral pathways are reviewed. A better understanding of how complex environmental variables affect plant phenology is important for future genetic manipulation of crops to increase productivity under the changing climate.

Hormone-regulated defense and stress response networks contribute to heterosis in Arabidopsis F1 hybrids.

Plant hybrids are extensively used in agriculture to deliver increases in yields, yet the molecular basis of their superior performance (heterosis) is not well understood. Our transcriptome analysis of a number of Arabidopsis F1 hybrids identified changes to defense and stress response gene expression consistent with a reduction in basal defense levels. Given the reported antagonism between plant immunity and growth, we suggest that these altered patterns of expression contribute to the greater growth of the hybrids. The altered patterns of expression in the hybrids indicate decreases to the salicylic acid (SA) biosynthesis pathway and increases in the auxin [indole-3-acetic acid (IAA)] biosynthesis pathway. SA and IAA are hormones known to control stress and defense responses as well as plant growth. We found that IAA-targeted gene activity is frequently increased in hybrids, correlating with a common heterotic phenotype of greater leaf cell numbers. Reduced SA concentration and target gene responses occur in the larger hybrids and promote increased leaf cell size. We demonstrated the importance of SA action to the hybrid phenotype by manipulating endogenous SA concentrations. Increasing SA diminished heterosis in SA-reduced hybrids, whereas decreasing SA promoted growth in some hybrids and phenocopied aspects of hybrid vigor in parental lines. Pseudomonas syringae infection of hybrids demonstrated that the reductions in basal defense gene activity in these hybrids does not necessarily compromise their ability to mount a defense response comparable to the parents.

Investigating the Association between Flowering Time and Defense in the Arabidopsis thaliana-Fusarium oxysporum Interaction.

Plants respond to pathogens either by investing more resources into immunity which is costly to development, or by accelerating reproductive processes such as flowering time to ensure reproduction occurs before the plant succumbs to disease. In this study we explored the link between flowering time and pathogen defense using the interaction between Arabidopsis thaliana and the root infecting fungal pathogen Fusarium oxysporum. We report that F. oxysporum infection accelerates flowering time and regulates transcription of a number of floral integrator genes, including FLOWERING LOCUS C (FLC), FLOWERING LOCUS T (FT) and GIGANTEA (GI). Furthermore, we observed a positive correlation between late flowering and resistance to F. oxysporum in A. thaliana natural ecotypes. Late-flowering gi and autonomous pathway mutants also exhibited enhanced resistance to F. oxysporum, supporting the association between flowering time and defense. However, epistasis analysis showed that accelerating flowering time by deletion of FLC in fve-3 or fpa-7 mutants did not alter disease resistance, suggesting that the effect of autonomous pathway on disease resistance occurs independently from flowering time. Indeed, RNA-seq analyses suggest that fve-3 mediated resistance to F. oxysporum is most likely a result of altered defense-associated gene transcription. Together, our results indicate that the association between flowering time and pathogen defense is complex and can involve both pleiotropic and direct effects.

Malignant neuroendocrine tumour of the appendix in childhood with loco-regional lymph node invasion.

VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1006600359152743.