Volatile Organic Compounds from Pythium oligandrum Play a Role in Its Parasitism on Plant-Pathogenic Pythium myriotylum.

The oomycete Pythium oligandrum is a soil-inhabiting parasite and predator of both fungi and oomycetes, and uses hydrolytic enzymes extensively to penetrate and hydrolyze its host or prey. Other mechanisms have been studied less, and we investigated the contribution of P. oligandrum-produced volatile organic compounds (VOCs) to parasitism. The growth-inhibiting activity of P. oligandrum VOCs was tested on Pythium myriotylum-a host or prey of P. oligandrum-coupled with electron microscopy, and biochemical and transcriptomic analyses. The P. oligandrum-produced VOCs reduced P. myriotylum growth by 80% and zoospore levels by 60%. Gas chromatography-mass spectrometry (GC-MS) identified 23 VOCs, and methyl heptenone, d-limonene, 2-undecanone, and 1-octanal were potent inhibitors of P. myriotylum growth and led to increased production of reactive oxygen species at a concentration that did not inhibit P. oligandrum growth. Exposure to the P. oligandrum VOCs led to shrinkage of P. myriotylum hyphae and lysis of the cellular membranes and organelles. Transcriptomics of P. myriotylum exposed to the P. oligandrum VOCs at increasing levels of growth inhibition initially showed a strong upregulation of putative detoxification-related genes that was not maintained later. The inhibition of P. myriotylum growth continued immediately after the exposure to the VOCs was discontinued and led to the reduced infection of its plant hosts. The VOCs produced by P. oligandrum could be another factor alongside hydrolytic enzymes contributing to its ecological role as a microbial parasite in particular ecological niches such as in soil, and may also contribute to the biocontrol of diseases using P. oligandrum commercial preparations. IMPORTANCE Microbe-microbe interactions in nature are multifaceted, with multiple mechanisms of action, and are crucial to how plants interact with microbes. Volatile organic compounds (VOCs) have diverse functions, including contributing to parasitism in ecological interactions and potential applications in biocontrol. The microbial parasite P. oligandrum is well known for using hydrolytic enzymes as part of its parasitism. We found that P. oligandrum VOCs reduced the growth of, and caused major damage to, the hyphae of P. myriotylum (a host or prey of P. oligandrum). Transcriptomic analyses of P. myriotylum exposed to the VOCs revealed the upregulation of genes potentially involved in an attempt to detoxify the VOCs. The inhibitory effects of the VOCs had a knock-on effect by reducing the virulence of P. myriotylum toward its plant hosts. The P. oligandrum VOCs could contribute to its ecological role as a microbial parasite. The VOCs analyzed here may also contribute to the biocontrol of diseases using P. oligandrum commercial preparations.

Predictors of mortality in 217 COVID-19 patients in Northwest Ohio, United States: A retrospective study.

The coronavirus disease 2019 (COVID-19) pandemic continues to cause significant morbidity and mortality worldwide. This study aims to identify specific lab markers, complications, and treatments that may be associated with increased mortality in COVID-19 patients. This study is retrospective in nature; it included 217 COVID-19 positive patients who were admitted to a ProMedica Health System hospital in Northwest Ohio, United States, between March 25 and June 16, 2020. We collected various laboratory values, complications, and treatment courses. T test and χ2 analyses were used to predict mortality. COVID-19 test was confirmed via polymerase chain reaction. Of 217 patients included in the study, the mean age of the population was 63.13 (SD, 17.8), of which 194 (89.4%, mean age 61.7 years) survived while 23 (10.6%, mean age 74.6 years) died. Among them, 53% were females and 47% male. Laboratory values that were associated with mortality were low hemoglobin (p = .0046), elevated INR (p = .0005), low platelets (p = .0246) and elevated procalcitonin (p = .0472). Marginally significant laboratory values included elevated troponin (p = .0661), and elevated creatinine (p = .0741). Treatment with either antibiotic, antifungals, antivirals, blood transfusion, steroids, and intubation were all statistically significant for mortality. COVID-19 related complications with either ARDS, myocarditis, elevated INR, septic shock, or age greater than 63 were significant predictors of mortality. Low hemoglobin, elevated INR, Low platelet, elevated procalcitonin, treated with either antibiotic, antifungal, antiviral, blood transfusion, steroids, and intubation are associated with high mortality related to COVID-19 infection. Healthcare professionals must be aware of these predictors.

Polypharmacy and severe potential drug-drug interactions among older adults with cardiovascular disease in the United States.

BACKGROUND: Polypharmacy continues to be a topic of concern among older adults and puts patients at increased risk of potential drug-drug interactions (DDIs) and negative health outcomes. The objective of this study was to assess the prevalence of polypharmacy among older adults with cardiovascular disease (CVD) and to identify severe potential DDIs. METHODS: A retrospective chart review was conducted in a tertiary care center over a three-month period where we reviewed home medications of older adults upon hospital admission. Inclusion criteria were age ≥ 65 years, history of CVD, and admission to the cardiology service. Polypharmacy was defined as 5 or more medications taken concomitantly, hyper-polypharmacy was defined as 10 or more medications taken concomitantly, and severe potential DDIs were considered to be those belonging to category D or X using Lexicomp® Drug Information Handbook. Category D interaction states that modification of therapy should be considered while category X states that the combination should be absolutely avoided. RESULTS: A total of 404 patients with a mean age of 76.6 ± 7.4 years were included. Patients were taking an average of 11.6 ± 4.5 medications at home and 385 (95%) received polypharmacy, 278 (69%) received hyper-polypharmacy, and 313 (77.5%) had at least one severe potential DDI. Under category D, the most common potential DDIs were drugs with additive central nervous system (CNS) depressant effect and drugs that increase the risk of QT prolongation. Under category X, the most common potential DDIs were non-selective ß-blockers that may diminish the bronchodilator effect of ß2 agonists and drugs with anticholinergic properties that enhance the ulcerogenic effect of oral solid potassium. CONCLUSIONS: Polypharmacy, hyper-polypharmacy, and severe potential DDIs are very common in older adults with CVD. Clinicians should vigilantly review patients' drug records and adjust therapy accordingly to prevent adverse drug reactions and negative health outcomes.

Novel Genetic Dysregulations and Oxidative Damage in Fusarium graminearum Induced by Plant Defense Eliciting Psychrophilic Bacillus atrophaeus TS1.

This study elaborates inter-kingdom signaling mechanisms, presenting a sustainable and eco-friendly approach to combat biotic as well as abiotic stress in wheat. Fusarium graminearum is a devastating pathogen causing head and seedling blight in wheat, leading to huge yield and economic losses. Psychrophilic Bacillus atrophaeus strain TS1 was found as a potential biocontrol agent for suppression of F. graminearum under low temperature by carrying out extensive biochemical and molecular studies in comparison with a temperate biocontrol model strain Bacillus amyloliquefaciens FZB42 at 15 and 25 °C. TS1 was able to produce hydrolytic extracellular enzymes as well as antimicrobial lipopeptides, i.e., surfactin, bacillomycin, and fengycin, efficiently at low temperatures. The Bacillus strain-induced oxidative cellular damage, ultrastructural deformities, and novel genetic dysregulations in the fungal pathogen as the bacterial treatment at low temperature were able to downregulate the expression of newly predicted novel fungal genes potentially belonging to necrosis inducing protein families (fgHCE and fgNPP1). The wheat pot experiments conducted at 15 and 25 °C revealed the potential of TS1 to elicit sudden induction of plant defense, namely, H2O2 and callose enhanced activity of plant defense-related enzymes and induced over-expression of defense-related genes which accumulatively lead to the suppression of F. graminearum and decreased diseased leaf area.

Rectal indomethacin with topical epinephrine versus indomethacin alone for preventing Post-ERCP pancreatitis - A systematic review and meta-analysis.

BACKGROUND: Recent studies have compared the utility of rectal indomethacin with topical epinephrine (IE) sprayed on duodenal papilla and rectal indomethacin alone (IS) to prevent post-ERCP pancreatitis (PEP) with conflicting results. We performed a systematic review and meta-analysis to evaluate the benefit of using the combination prophylaxis as oppose to rectal indomethacin alone. METHODS: The following database were searched for our systematic review: PubMed∖Medline, Embase, Cochrane, and Web of Science. We included both randomized controlled trials (RCTs) and cohort studies. Primary outcome was incidence of PEP and secondary outcomes were adverse events and mortality. RESULTS: A total of 3 studies (all RCTs) with 2244 patients (1132 in IS and 1112 in IE group) were included. The IE group did not demonstrate any significant benefit over IS group in preventing PEP (RR: 1.15, 95% CI 0.62-2.2), mortality (RR: 0.85, 95% CI 0.22-3.24) or overall adverse events (RR: 1.3, 95% CI 0.93-1.7). CONCLUSION: The combination of rectal indomethacin and topical epinephrine failed to demonstrate any benefit over indomethacin alone in preventing PEP, decreasing mortality and overall adverse events.

Use of over the counter products in older cardiovascular patients admitted to a tertiary care center in USA.

BACKGROUND: In recent years there has been a substantial increase in the use of over-the-counter (OTC) products around the world. While they are assumed to be safe by consumers, they can potentially lead to adverse effects and drug interactions particularly in older adults. METHODS: We assessed the patterns of OTC products used by older adults admitted to the cardiology service in a tertiary care medical center in the USA over a three month period. We conducted a retrospective chart review where older adults with cardiovascular diseases (CVD) who were taking at least one OTC product at home were included. RESULTS: Out of 404 patients who were admitted to the cardiology service, 281 (69.6%) were taking OTC products. Patients were taking a total of 659 OTC products; mean of 2.35 ± 1.57 and the range varied from 1 to 9 products. The most commonly used products were vitamins (37.3%), followed by laxatives (17%), minerals (13.6%), stomach acid reducers (9%), and analgesics (3.6%). OTC users were found to be suffering from more comorbidities and received more prescription medications as compared to non-users. Gender and age did not have an impact on the use of OTC products while patients with atrial fibrillation, sleep apnea and gastro-esophageal reflux disease were more likely to use OTC products. CONCLUSION: Use of OTC products is quite frequent in older adults with CVD in our study. Clinicians should ask about OTC product usage and counsel patients about the risks and benefits associated with their use.

Pulmonary Nocardia beijingensis infection associated with the use of alemtuzumab in a patient with multiple sclerosis.

Nocardia is a Gram-positive aerobic pathogen that usually affects immunocompromised patients. We report a case of pulmonary infection caused by a rare Nocardia species, Nocardia beijingensis, in a 50-year-old woman who had received alemtuzumab for the treatment of her multiple sclerosis. The invasive pulmonary infection was successfully treated with meropenem.

Potentially inappropriate home medications among older patients with cardiovascular disease admitted to a cardiology service in USA.

BACKGROUND: The use of potentially inappropriate medications (PIMs) may pose more risks than benefits to patients and is a major factor contributing to the likelihood of serious adverse drug reactions and negative health outcomes among older patients. METHODS: A retrospective chart review was conducted in a tertiary care center in USA where home medications of the older patients were reviewed and analyzed upon hospital admission over three months, from March till May 2016. Inclusion criteria were age of 65 years and above, history of cardiovascular disease, and admission to the cardiology service. The aim of our study was to determine the frequency and factors associated with PIMs, by applying the updated Beers 2015 criteria. RESULTS: A total of 404 patients were included in the study and were taking a total of 4669 medications at home, an average of 11.6 ± 4.5 medications per patient. The proportion of PIMS was 20% of all medications reported, with an average of 2.4 PIM per patient, and 87.4% of patients were receiving at least one PIM. Significant association was found between use of PIMs and number of home medications, female gender, and number and types of comorbidities. Comorbidities associated with more PIMs were heart failure, atrial fibrillation/flutter, history of falls/fractures, cerebrovascular accident, and depression. The most commonly prescribed PIMs were: drugs that may exacerbate or cause syndrome of inappropriate antidiuretic hormone secretion or hyponatremia (29.7%), scheduled use of proton pump inhibitors (PPIs) > 8 weeks in non-high-risk patients (11.3%), and benzodiazepines (8.1%). CONCLUSIONS: A high prevalence of PIMs in older patients with cardiovascular disease was observed. Provider education and detailed assessment of medication lists upon hospital admission by multidisciplinary teams can help in preventing the use of PIMs.

What's New in the Orthopaedic Treatment of Cerebral Palsy.

BACKGROUND: The orthopaedic treatment of the patient with cerebral palsy (CP) is complex and must take into account the heterogeneity and natural history of the condition. Although the goals of management are for the most part universal, the specific interventions and outcome measures used to reach these goals are wide ranging. This update serves to summarize some of the recent publications in the field of pediatric orthopaedics that have made important contributions to our understanding and care of the patient with CP. METHODS: We searched the PubMed database using the following terms: "cerebral palsy" AND "orthopedic." The results were then filtered to include only review papers or clinical trials published in English from 2010 to 2014. The obtained list of references was then reviewed for publications in the fields of lower extremity muscle imbalance, foot and ankle deformities, hip and acetabular dysplasia, and advances in orthopaedic-related technology. RESULTS: Updates in the field of pediatric orthopaedics are constant and the current level of evidence for the effectiveness of specific treatment modalities in patients with CP was reviewed. The search method yielded 153 publications, of which 31 papers were identified as having contributed important new findings. CONCLUSIONS: Our understanding of orthopaedic treatments for children with CP continues to grow and expand. The studies reviewed illustrate just some of the strides we have taken in utilizing evidence-based surgical decision making in practice. Nevertheless, there remains a paucity of randomized controlled trials and higher evidence research, which may contribute to the variability in current practices among providers. By elucidating these gaps we can more purposefully delegate our time and resources into targeted areas of research. LEVEL OF EVIDENCE: Level 4-literature review.

Comparison of Early Adverse Events After Operative Treatment of Bimalleolar and Trimalleolar Fractures Versus Pilon Fractures.

Ankle fractures requiring open reduction and internal fixation vary in severity from unimalleolar fractures to bimalleolar/trimalleolar (BT) fractures to pilon fractures. Consequently, the postoperative outcomes with these surgeries can vary. Most previous studies of these injuries had small sample sizes, studied a single risk factor or adverse event, or did not compare different injuries by severity. The purpose of the present study was to describe and compare the patient characteristics and postoperative outcomes of 2 high-energy ankle fractures: BT and pilon fractures. The relevant patients were identified from the American College of Surgeons National Surgical Quality Improvement Program database using the Current Procedural Terminology codes for BT and pilon fractures. Patient demographics, characteristics, comorbidities, and 30-day mortality and adverse events were recorded and compared between the 2 types of ankle fractures. More than 45% of patients with these fracture types were aged 40 to 65 years. Pilon fractures occurred more frequently in younger patients, were more likely to occur in men, required a longer hospital stay and operative time, were less likely to occur in patients with a body mass index of >30 kg/m2, and conferred a greater risk of wound complications (odds ratio 1.76; p = .048) compared with BT fractures. The findings from the present study help us understand the differences in patient characteristics and potential early adverse events after open reduction and internal fixation of BT fractures versus pilon fractures.

Alzheimer and vascular dementia in the elderly patients.

OBJECTIVES: To find out the frequency of Alzheimer's and Vascular dementia in the elderly patients. METHODS: This cross sectional descriptive study was conducted in Department of Medicine, Ziauddin Hospital Karachi from 1st October 2013 to 31st March 2014. Patients with symptoms of dementia for more than 6 months duration, and Mini Mental State Examination score <24 were included in this study. Patients who fell in category of dementia were assessed for duration of symptoms. Patients underwent CT scan of brain. Patients with generalized atrophy of brain on CT scanning of brain were labeled as Alzheimer's dementia, while patients with ischemic or hemorrhagic stroke on CT scan of brain were labeled as vascular dementia. RESULTS: Four hundred twenty two patients were included in this study. There were 232 (54.98 %) male and 190 (45.02 %) were female. The mean age ± SD of the patients was 72.58±5.34 years (95% CI: 72.07 to 73.09), similarly average duration of symptoms was 10.14±2.85 months. About 18.96% of patients were illiterate, 32.23% were matric, 28.44% were intermediate and 20.33% were graduate and post graduate. Hypertension and diabetes were the commonest co-morbid i.e. 81.3% and 73.7%, hyperlipedimia and smoking were 38.2% and 45% respectively. Frequency of Alzheimer's disease and vascular dementia in the elderly was observed in 3.79% (16/422) and 2.61% (11/422) cases. CONCLUSION: A good number of patients, 27 out of 422, in this hospital based study were suffering from Alzheimer's disease and vascular dementia. Early detection and prompt treatment can reduce the burden of the disease in our population.

The Use of Drugs that Should be Avoided or Used with Caution in Patients Hospitalized for Acute Decompensated Heart Failure.

BACKGROUND: Heart failure (HF) is a pervasive global health concern, with acute decompensated heart failure (ADHF) contributing significantly to morbidity and mortality. Medications used in patients with HF may exacerbate HF or prolong the QT interval, posing additional risks. OBJECTIVE: The objective is to assess the prevalence and utilization patterns of medications known to cause or exacerbate HF and prolong the QT interval among patients with ADHF. Understanding these patterns is crucial for optimizing patient care and minimizing potential risks. METHODS: A retrospective chart review was conducted at Huntsville Hospital, Huntsville, USA, covering 602 patients with ADHF over a 40-month period. Inclusion criteria involved age ≥ 18 years, a history of HF, and ADHF admission. The 2016 American Heart Association Scientific Statement was used to identify drugs that may cause or exacerbate HF and those that could prolong the QT interval RESULTS: Among the 602 patients, 57.3% received medications causing or exacerbating HF, notably albuterol (34.9%) and diabetes medications (20.4%), primarily metformin, followed by urologic agents (14.3%), mostly tamsulosin, and nonsteroidal anti-inflammatory drugs (NSAIDs) (6.1%). Moreover, 82.9% were on medications prolonging the QT interval, with loop diuretics, amiodarone, ondansetron, and famotidine most prevalent. Furthermore, 42.1% of the patients received more than two concomitant medications that prolong the QT interval, which can further exacerbate the risk of torsades de pointes. CONCLUSION: This study underscores the high prevalence of HF-causing or HF-exacerbating medications and QT-prolonging drugs in patients with ADHF. Healthcare professionals must be cognizant of these patterns, advocating for safer prescribing practices to optimize patient outcomes and reduce the burden of HF-related hospitalizations.

Genotypes, epidemiological variables and fungicides application associated with wheat leaf rust development and grain yield.

The present study was carried out at the Plant Pathology Hafizabad Research Station, the University of Layyah, during the crop seasons 2021-2022 and 2022-2023 to evaluate the response of various wheat genotypes against leaf rust severity (%), environmental conditions favourable for disease development and grain yield. Except for minimum temperature and minimum relative humidity, which had a negative association with disease development, there was a significant correlation between leaf rust severity (%) and all environmental conditions such as maximum temperature, maximum relative humidity, rainfall, and wind speed. All epidemiological variables such as maximum temperature, minimum temperature, minimum relative humidity, rainfall and wind speed significantly affect the disease progression. The disease predictive model accounted for 48-69 % variability in leaf rust severity. The model performance was evaluated using the coefficient of determination (R2 = 0.69) and RMSE, both demonstrated acceptable predictive results for leaf rust severity (%) management. Leaf rust severity (%) increased with an increase in maximum temperature (17.8-30 °C), maximum relative humidity (76.3-85 %), rainfall (2.2-10.85 mm) and wind speed 1.1-2.7 km/h and decreased with the increase of minimum temperature (7.91-16.71 °C) minimum relative humidity (47.15-56.45 %) during both rating seasons 2021-2022 and 2022-2023. The single and two applications of fungicides at the Zadok's scale 3, ZS 4.3, and ZS 5.4 stages led to a significant reduction in grain yield losses caused by leaf rust severity (%) in both the 2021-2022 and 2022-2023 crop seasons. Single and two sprays of prothioconazole, were found to be the first choice among all treatments to reduce the disease severity and increase grain production and maximum gross revenue (513.1-777.8$/ha), as compared to followed by single and two sprays of propiconazole (Progress), tebuconazole + trifloxystrobin, tebuconazole, bixafen + tebuconazole, and propiconazole (Tilt), respectively. These findings recommend the involvement of genotype resistance and weather predictors in wheat leaf rust development, along with fungicide application studies, to improve the predictability of host resistance to disease, future models, and the sustainability of disease control methods.

Efficacy and Safety of Activated Prothrombin Complex Concentrate for Reversal of the Anticoagulant Effect of Apixaban and Rivaroxaban in Patients with Major Bleeding.

BACKGROUND: The use of activated prothrombin complex concentrate (aPCC) to treat direct oral anticoagulant (DOAC)-associated bleeding is off-label and clinical experience is limited. OBJECTIVES: We aimed to assess the efficacy and safety of aPCC in reversing the anticoagulant effect of apixaban and rivaroxaban in patients presenting with major bleeding. METHODS: A retrospective cohort study of adult non-randomized patients was conducted at a tertiary referral medical center in the United States (US) to investigate the use of aPCC for the reversal of the anticoagulant effect of apixaban and rivaroxaban in patients presenting with major bleeding. The primary outcome was achieving clinical hemostasis according to prespecified criteria. Safety outcomes included the occurrence of thrombotic events during hospitalization. RESULTS: A total of 217 patients were included in the study. Intracranial hemorrhage (ICH) was the most common site of bleeding (n = 100, 46.1%), followed by gastrointestinal bleed (n = 87, 40.1%). Clinical hemostasis was achieved in 170 patients (78.3%), and the risk of not achieving hemostasis with ICH-related bleeding was significantly higher than that of non-ICH-related bleeding (2.5, 95% confidence interval [CI] 1.44-4.34; p < 0.001). Eight patients not achieving hemostasis died during hospitalization, all of whom were suffering from ICH, and mortality associated with non-ICH-related bleeding was significantly lower compared with ICH-related bleeding (0.91, 95% CI 0.86-0.97; p < 0.001). Thromboembolic events during hospitalization occurred in one patient (0.5%). CONCLUSIONS: The use of aPCC for the management of apixaban- or rivaroxaban-related major bleeding is effective in most cases and is associated with a low risk of thromboembolism.

Plant-Microbes Interaction: Exploring the Impact of Cold-Tolerant Bacillus Strains RJGP41 and GBAC46 Volatiles on Tomato Growth Promotion through Different Mechanisms.

The interaction between plant and bacterial VOCs has been extensively studied, but the role of VOCs in growth promotion still needs to be explored. In the current study, we aim to explore the growth promotion mechanisms of cold-tolerant Bacillus strains GBAC46 and RJGP41 and the well-known PGPR strain FZB42 and their VOCs on tomato plants. The result showed that the activity of phytohormone (IAA) production was greatly improved in GBAC46 and RJGP41 as compared to FZB42 strains. The in vitro and in-pot experiment results showed that the Bacillus VOCs improved plant growth traits in terms of physiological parameters as compared to the CK. The VOCs identified through gas chromatography-mass spectrometry (GC-MS) analysis, namely 2 pentanone, 3-ethyl (2P3E) from GBAC46, 1,3-cyclobutanediol,2,2,4,4-tetramethyl (CBDO) from RJGP41, and benzaldehyde (BDH) from FZB42, were used for plant growth promotion. The results of the partition plate (I-plate) and in-pot experiments showed that all the selected VOCs (2P3E, CBDO, and BDH) promoted plant growth parameters as compared to CK. Furthermore, the root morphological factors also revealed that the selected VOCs improved the root physiological traits in tomato plants. The plant defense enzymes (POD, APX, SOD, and CAT) and total protein contents were studied, and the results showed that the antioxidant enzymes and protein contents significantly increased as compared to CK. Similarly, plant growth promotion expression genes (IAA4, ARF10A, GA2OX2, CKX2, and EXP1) were significantly upregulated and the ERF gene was downregulated as compared to CK. The overall findings suggest that both Bacillus isolates and their pure VOCs positively improved plant growth promotion activities by triggering the antioxidant enzyme activity, protein contents, and relative gene expressions in tomato plants.

Composition and assembly mechanisms of prokaryotic communities in wetlands, and their relationships with different vegetation and reclamation methods.

Coastal wetlands are undergoing substantial transformations globally as a result of increased human activities. However, compared to other ecosystems, diversity and functional characteristics of microbial communities in reclaimed coastal wetlands are not well studied compared to other ecosystems. This is important because it is known that microorganisms can play a crucial role in biogeochemical cycling within coastal wetland ecosystems. Hence, this study utilized the high-throughput sequencing technique to investigate the structure and assembly processes of microbial communities in reclaimed coastal wetlands. The results revealed a substantial change in soil properties following coastal wetland reclamation. Remarkably, the reclaimed soil exhibited significantly lower pH, soil organic carbon (SOC), and total salinity (TS) values (p < 0.05). The dominant phyla included Proteobacteria, Chloroflexi, Bacteroidetes, Acidobacteria, and Planctomycetes among study sites. However, the relative abundance of Proteobacteria increased from un-reclaimed coastal wetlands to reclaimed ones. The Proteobacteria, Chloroflexi, and Acidobacteria showed higher relative abundance in vegetated soil compared to bare soil, while Bacteroidetes and Planctomycetes exhibited the opposite trend. Notably, vegetation types exerted the strongest influence on microbial diversity, surpassing the effects of soil types and depth (F = 34.49, p < 0.001; F = 25.49, p < 0.001; F = 3.173, p < 0.078, respectively). Stochastic assembly processes dominated in un-reclaimed soil, whereas deterministic processes governed the assembly in artificial sea embankment wetlands (SEW). The presence of Spartina alterniflora in all soil types (except SEW soils) indicated stochastic assembly, while Phragmites australis in reclaimed soils pointed toward deterministic microbial assembly. Furthermore, environmental factors such as pH, soil water content (SWC), SOC, total carbon (TC), total nitrogen (TN), total phosphorus (TP), NH4+-N, vegetation types, soil depth, and geographic distance exhibited significant effects on microbial beta diversity indices. Co-occurrence network analysis revealed a stronger association between taxa in SEW compared to land reclaimed from wetlands (LRW) and natural coastal wetlands (NCW). The bottom soil layer exhibited more complex network interactions than the topsoil layer. Besides soil parameters, reclamation and varieties of vegetation were also substantial factors influencing the composition, diversity, and assembly processes of microbial communities in coastal wetlands.

Volatile Organic Compounds Emitted by the Biocontrol Agent Pythium oligandrum Contribute to Ginger Plant Growth and Disease Resistance.

The oomycete Pythium oligandrum is a potential biocontrol agent to control a wide range of fungal and oomycete-caused diseases, such as Pythium myriotylum-caused rhizome rot in ginger, leading to reduced yields and compromised quality. Previously, P. oligandrum has been studied for its plant growth-promoting potential by auxin production and induction of disease resistance by elicitors such as oligandrin. Volatile organic compounds (VOCs) play beneficial roles in sustainable agriculture by enhancing plant growth and resistance. We investigated the contribution of P. oligandrum-produced VOCs on plant growth and disease suppression by initially using Nicotiana benthamiana plants for screening. P. oligandrum VOCs significantly enhanced tobacco seedling and plant biomass contents. Screening of the individual VOCs showed that 3-octanone and hexadecane promoted the growth of tobacco seedlings. The total VOCs from P. oligandrum also enhanced the shoot and root growth of ginger plants. Transcriptomic analysis showed a higher expression of genes related to plant growth hormones and stress responses in the leaves of ginger plants exposed to P. oligandrum VOCs. The concentrations of plant growth hormones such as auxin, zeatin, and gibberellic acid were higher in the leaves of ginger plants exposed to P. oligandrum VOCs. In a ginger disease biocontrol assay, the VOC-exposed ginger plants infected with P. myriotylum had lower levels of disease severity. We conclude that this study contributes to understanding the growth-promoting mechanisms of P. oligandrum on ginger and tobacco, priming of ginger plants against various stresses, and the mechanisms of action of P. oligandrum as a biocontrol agent. IMPORTANCE Plant growth promotion plays a vital role in enhancing production of agricultural crops, and Pythium oligandrum is known for its plant growth-promoting potential through production of auxins and induction of resistance by elicitors. This study highlights the significance of P. oligandrum-produced VOCs in plant growth promotion and disease resistance. Transcriptomic analyses of leaves of ginger plants exposed to P. oligandrum VOCs revealed the upregulation of genes involved in plant growth hormone signaling and stress responses. Moreover, the concentration of growth hormones significantly increased in P. oligandrum VOC-exposed ginger plants. Additionally, the disease severity was reduced in P. myriotylum-infected ginger plants exposed to P. oligandrum VOCs. In ginger, P. myriotylum-caused rhizome rot disease results in severe losses, and biocontrol has a role as part of an integrated pest management strategy for rhizome rot disease. Overall, growth enhancement and disease reduction in plants exposed to P. oligandrum-produced VOCs contribute to its role as a biocontrol agent.