Arbuscular mycorrhizal fungi enhance monoterpene production in red clover (Trifolium pratense L.): a potential tool for pest control.

The possibility of modifying terpene production in plants is a defensive strategy that has been studied in conjunction with their biosynthetic pathways. A biotic factor such as Arbuscular Mycorrhizal Fungi (AMF) could modify terpene production in Trifolium pratense L. In this work, the enzymatic production of monoterpenes in Superqueli INIA cultivar with two AMF was evaluated via HeadSpace-Gas Chromatography (HS-GC). A significant increase of (S)-limonene was found in plants inoculated with Claroideoglomus claroideum as well as with the AMF mix (genera Scutellospora, Acaulospora and Glomus). Moreover, significant increases in other monoterpenes such as (-)-ß-pinene, myrcene, linalool, were observed. Results showed higher monoterpene production capacities in the Superqueli-INIA cultivar, suggesting the participation of monoterpene synthases (MTS). The significant rise of (S)-limonene in red clover plants inoculated with AMF suggests this strategy could be implemented in an agronomical manage for controlling the H. obscurus, the primary pest.

Application of Arbuscular Mycorrhizal Fungi in Vineyards: Water and Biotic Stress Under a Climate Change Scenario: New Challenge for Chilean Grapevine Crop.

The crop Vitis vinifera (L.) is of great economic importance as Chile is one of the main wine-producing countries, reaching a vineyard area of 145,000 ha. This vine crop is usually very sensitive to local condition changes and agronomic practices; therefore, strategies to counteract the expected future decrease in water level for agricultural irrigation, temperature increase, extreme water stress (abiotic stress), as well as increase in pathogenic diseases (biotic stress) related to climate change will be of vital importance for this crop. Studies carried out in recent years have suggested that arbuscular mycorrhizal fungi (AMF) can provide key ecosystem services to host plants, such as water uptake implementation and enhanced absorption of nutrients such as P and N, which are key factors for improving the nutritional status of the vine. AMF use in viticulture will contribute also to sustainable agronomic management and bioprotection against pathogens. Here we will present (1) the current status of grapevines in Chile, (2) the main problems in grapevines related to water stress and associated with climate change, (3) the importance of AMF to face water stress and pathogens, and (4) the application of AMF as a biotechnological and sustainable tool in vineyards.

Arbuscular mycorrhizal fungi from acidic soils favors production of tomatoes and lycopene concentration.

BACKGROUND: Tomato is widely consumed throughout the world for its flavor and nutritional value. This functional food largely depends on the implementation of new strategies to maintain the nutraceutical value, e.g. lycopene concentration, and overcome the challenges of sustainable production and food security. The use of arbuscular mycorrhizal fungi (AMF)-based biostimulants represents one of the most promising tools for sustainable management of agricultural soils, being fundamental for organic food production, reducing fertilizers and pesticides use, and decreasing environmental damage. This study aimed at elucidating whether native arbuscular mycorrhizal fungi (AMF) could positively affect tomato yield and lycopene concentration. RESULTS: Native AMF inoculum consisted of two inoculum types: the single species Claroideoglomus claroideum, and a mix of Scutellospora calospora, Acaulospora laevis, Claroideoglomus claroideum, and Claroideoglomus etunicatum. At the end of the study up to 78% of the root system was colonized by single inoculum. Tomato diameters in single and mix mycorrhizal plants showed increases of 80% and 35% respectively. Fresh weights were 84% and 38% higher with single and mix inocula compared with the controls, respectively. The lycopene concentration in tomato fruits of plants with single and mix inoculum was higher than controls. The lycopene concentration was 124.5% and 113.9% greater in single and mix than non-inoculated plants. CONCLUSION: Tomato diameters, fresh weight and lycopene concentration was significantly higher in plants colonized by AMF compared with uninoculated plants. Results suggest that the role of single species Claroideoglomus claroideum could generate better plant performance due to its high production of extraradical mycelium. © 2021 Society of Chemical Industry.

Showing their mettle: extraradical mycelia of arbuscular mycorrhizae form a metal filter to improve host Al tolerance and P nutrition.

BACKGROUND: New evidence has shown that arbuscular mycorrhizal (AM) fungi can contribute to the aluminum (Al3+ ) tolerance of host plants growing in acidic soils with phytotoxic levels of Al3+ . The aim of this study was to investigate the role of AM fungi isolated from naturally occurring Al3+ acidic soils in conferring host tolerance to Al3+ toxicity in three wheat cultivars differing in Al3+ sensitivity. The experiment was conducted in a soilless substrate (vermiculite/perlite, 2:1 v/v) using two Al3+ -tolerant wheat genotypes and one Al3+ -sensitive wheat genotype. The wheat was colonized with a consortium of AM fungi isolated from an Andisol, with or without Al3+ at a concentration of 200 µmol L-1 . RESULTS: The response of wheat to Al3+ in the medium was dependent on both the plant genotype and AM colonization. The benefits of the AM fungi to the wheat cultivars included an increased P concentration and relatively low Al3+ accumulation in the plants. This was achieved through two mechanisms. First, the metal-chelating capacity of the AM fungi was clear in two of the cultivars ('Tukan' and 'Porfiado'), in which the enhanced extraradical mycelium development was able to retain Al3+ in the glomalin and hyphae. Second, the increased AM-induced acid phosphatase activity in the rhizosphere of the other cultivar ('Atlas 66') increased host nutrition possibly by hyphae-mediated nutrient uptake and glomalin-related soil protein. CONCLUSION: The results suggest that the role of AM fungi in cultivar-specific Al3+ detoxification can be achieved by increased extraradical mycelial filters and enhanced bioavailability of P in the host rhizosphere. © 2019 Society of Chemical Industry.

An epidemiological and molecular study regarding the spread of vancomycin-resistant Enterococcus faecium in a teaching hospital in Bogotá, Colombia 2016.

BACKGROUND: Enterococcus faecium is ranked worldwide as one of the top ten pathogens identified in healthcare-associated infections (HAI) and is classified as one of the high priority pathogens for research and development of new antibiotics worldwide. Due to molecular biology techniques' higher costs, the approach for identifying and controlling infectious diseases in developing countries has been based on clinical and epidemiological perspectives. Nevertheless, after an abrupt vancomycin-resistant Enterococcus faecium dissemination in the Méderi teaching hospital, ending up in an outbreak, further measures needed to be taken into consideration. The present study describes the vancomycin-resistant Enterococcus faecium pattern within Colombian's largest installed-bed capacity hospital in 2016. METHODS: Thirty-three vancomycin-resistant Enterococcus faecium isolates were recovered during a 5-month period in 2016. Multilocus variable-number tandem-repeat analysis was used for molecular typing to determine clonality amongst strains. A modified time-place-sequence algorithm was used to trace VREfm spread patterns during the outbreak period and estimate transmission routes. RESULTS: Four clonal profiles were identified. Chronological clonal profile follow-up suggested a transitional spread from profile "A" to profile "B", returning to a higher prevalence of "A" by the end of the study. Antibiotic susceptibility indicated high-level vancomycin-resistance in most isolates frequently matching vanA gene identification. DISCUSSION: Transmission analysis suggested cross-contamination via healthcare workers. Despite epidemiological control of the outbreak, post-outbreak isolates were still being identified as having outbreak-related clonal profile (A), indicating reduction but not eradication of this clonality. This study supports the use of combined molecular and epidemiological strategies in an approach to controlling infectious diseases. It contributes towards a more accurate evaluation of the effectiveness of the epidemiological measures taken regarding outbreak control and estimates the main cause related to the spread of this microorganism.

Association Between Confocal Morphologic Classification and Clinical Phenotypes of Multiple Primary and Familial Melanomas.

Importance: The improved knowledge of clinical, morphologic, and epidemiologic heterogeneity of melanoma in the context of multiple primary and familial melanomas may improve prevention, diagnosis, and prognosis of melanoma. Objective: To characterize reflectance confocal microscopy (RCM) morphologic patterns of melanomas in multiple primary and familial melanomas. Design, Setting, and Participants: In this cross-sectional, retrospective study, patients in a hospital-based referral center were recruited from March 1, 2010, through August 31, 2013; data analysis was conducted from September 1, 2013, through May 31, 2014. Consecutive primary melanomas, documented by dermoscopic and confocal examination, from multiple primary and familial melanomas with known CDKN2A mutational status were studied. Main Outcomes and Measures: Epidemiologic, genetic, dermoscopic, and histologic data were evaluated according to an RCM morphologic classification: dendritic cell, round cell, dermal nest, combined, and nonclassifiable types. Results: Fifty-seven melanomas from 50 patients (28 women [56%] and 49 white patients [98%]) were included: 23 dendritic cell (40%), 21 round cell (37%), 2 dermal nests (4%), 2 combined (4%), and 9 nonclassifiable (16%). The median (SD) age of the participants was 53.0 (16.9) years (interquartile range, 41.8-71.2 years), and the median (SD) age at the first melanoma was 46.0 (17.1) years (interquartile range, 35.8-61.5 years). Dendritic cell melanoma was characterized by older age at diagnosis, phototypes 2 and 3, more intense solar exposure, and moderate to severe solar lentigines; it was the most prevalent confocal type in facial lesions and was associated with the lentigo maligna histologic subtype. Round cell melanomas were identified more often in the familial context and in individuals with phototype 1 skin types; RCM features, such as junctional thickening, dense dermal nests, and nucleated cells within papillary dermis, were more frequently found in this subtype. Dermal nest and combined melanoma were associated with the absence of pigmented network on dermoscopy and thicker tumors on histologic analysis. Nonclassifiable type was associated, by RCM, with the absence of pagetoid cells on confocal examination and lower frequency of marked atypia on melanocytes in the basal cell layer; it presented with lower ABCD Total Dermoscopy Scores and RCM scores compared with the other types. CDKN2A mutation carriers may develop any RCM type of melanoma. Conclusions and Relevance: Different routes to develop melanoma can be identified according to RCM morphologic classification, with dendritic cell melanomas being associated with chronic sun damage and round cell melanoma with early age at onset and phototype 1 in the context of multiple primary and familial melanomas. The morphologic expression of melanomas via dermoscopy and confocal examination varies according to differences in tumor stage and biological behavior.

Investigación de la ingesta de sal mediante natriuresis en escolares de 6 a 13 años de La Pampa / RESEARCH IN SALT INTAKE BY NATRIURESIS IN CHILDREN AGED 6 TO 13 THE PROVINCE OF LA PAMPA

Introducción: en la provincia de La Pampa prevalece una alta ingesta de carnes y fiambres. Existe promoción en adultos para disminuir la ingesta de sal, no focalizada en niños. Objetivos: investigar en escolares de la comunidad agrícolaganadera la ingesta de sal mediante la natriuresis y determinar riesgo de hipertensión arterial. Materiales y métodos: estudio piloto, exploratorio, descriptivo en 67 niños/niñas de 6-13 años, de escuela de jornada completa, sin restricción dietética. Se determinó frecuencia de ingesta de fiambres, peso, talla e IMC, perímetro de cintura mínima (cm) y un control de presión arterial (PA). Se describen los resultados según sexo, edad y percentiles (Pc) de talla (Task Force, 2004). Se determinó natriuresis (matutina y vespertina) e ingesta de sal (método de Tanaka, et al.). Se informaron los resultados a la familia y se educó sobre los factores de riesgo cardiovasculares. Resultados: el 96% consumía frecuentemente fiambres, el 14,66% tenía un Pc de PA anormal. Las niñas mayores de 9 años tuvieron mayor peso (p:0,01) e IMC que los varones (p:0,02). Los varones menores de 9 años tenían mayores niveles de natriuresis matutina que las niñas (p:0,04). La ingesta de sal/24 h de las niñas menores de 9 años fue de 2,48±1,99 g y 3,19±0,36 g en las mayores (p:0,09), siendo de 1,82±0,56 y 3,27±1,03 g respectivamente en los niños (p:0,01). Conclusiones: hallamos un consumo elevado de sal en la población estudiada, aumentando significativamente en varones a partir de los 9 años poniéndolos en riesgo de hipertensión arterial. Se debe efectuar un programa de alimentación saludable especialmente a partir de esta edad para el control de peso en las niñas y de la ingesta de sal en los niños, informando a los médicos responsables para que efectúen el control de la presión arterial en particular.

Effect of dairy manure rate and the stabilization time of amended soils on atrazine degradation.

The application rate of liquid cow manure (LCM) in the field and the stabilization time of amended soils before application of pre-plant herbicides are factors that determine their efficiency. This study includes evaluation of residual atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) in soil and amended soils with equivalent rate of 100,000; 200,000; and 300,000 L ha(-1) of LCM and the effect of pre-incubation time of amended soils on atrazine degradation. The study was carried out under controlled conditions using an Andisol with previous historical application of atrazine. The respiratory activity and fluorescein diacetate (FDA) studies indicated that the time necessary for stabilization of amended soils is over 20-30 d. During the measurement of respiratory and FDA activity, no significant differences were observed when atrazine was applied. The half-life of atrazine ranged from 5 to 8d and the relative distribution of degradation products seem to be affected by the application of LCM. The pre-incubation time of amended soil and LCM dose would not affect atrazine degradation rate, when the soil has a history of herbicide application. However, repeated applications of LCM in a long period of time could change the soil pH and increase the content of dissolved organic carbon (DOC) which could further contribute to a faster degradation of atrazine. Both effects would reduce the effectiveness of atrazine in weed control.