RESUMEN
This work presents the isolation of endophytic fungi from the leaves of Campomanesia adamantium (Cambess.) O. Berg (Myrtaceae), a native species found in Brazil and popularly known as "guabiroba-do-campo", with abundant distribution in the Brazilian Cerrado. It has been popularly used for its anti-rheumatic, anti-inflammatory, antidiarrheal, blood cholesterol-reducing, urinary antiseptic, and depurative properties. Theese fungi are microorganisms that live inside higher plants, at least for a period of their life cycle, occupying the intercellular spaces of plant tissues such as leaves and stems. These fungi are harmless to the host plant, and their secondary metabolites promote protection, regulate growth, combat bacteria, viruses, and fungi, and promote resistance to abiotic stress, as well as insecticidal effects. Endophytic fungi associated with the leaves of C. adamantium were isolated using the culture medium isolation technique. After growth, the fungi were divided into groups based on morphotypes. Fungal genomic DNA was extracted, and a polymerase chain reaction (PCR) was conducted to amplify the ITS1-5.8S-ITS2 regions of rRNA, and the nucleotide sequences obtained were compared with those available in the GenBank database for molecular identification of the isolates. The phylogenetic tree was constructed using MEGA 11 software. The results showed representatives of the Ascomycota phylum, and it was possible to identify at the genus level 18 fungi of the genera Colletotrichum, Diaporthe, Epicoccum, and Neofusicoccum.
Asunto(s)
Endófitos , Hongos , Myrtaceae , Hojas de la Planta , Endófitos/aislamiento & purificación , Endófitos/clasificación , Endófitos/genética , Brasil , Myrtaceae/microbiología , Hongos/clasificación , Hongos/aislamiento & purificación , Hongos/genética , Hojas de la Planta/microbiología , ADN de Hongos/genética , Reacción en Cadena de la Polimerasa , FilogeniaRESUMEN
The secondary metabolism products of plants have influenced great economic interest, given their chemical diversity and biological activities. Because of this, this study evaluates the phytochemical composition, antimicrobial activity, insecticidal, and antioxidant activity of plant extracts and oil of Myrcia oblongata. Saponins, steroids, triterpenoids, tannins, and flavonoids were detected. The extracts showed antimicrobial capacity on the tested microorganisms, except for the methanolic extract, which showed no activity for P. mirabilis and S. enteritidis. Regarding the analysis of antioxidant compounds, the hexanic, ethyl acetate and acetone extracts showed higher antioxidant activities and also higher insecticidal performance on Alphitobius diaperinus larvae, resulting in 80% adult mortality. The results reported here show that there may be a relationship between antioxidant potential and the insecticidal effect of Myrcia oblongata DC. The components present in both the extract and the oil can be used as natural alternative to synthetic compounds in the biological control of parasites and pathogenic microorganisms.
Os produtos do metabolismo secundário das plantas têm despertado grande interesse econômico, dada sua diversidade química e atividades biológicas. Neste sentido, o estudo objetivou avaliar a composição fitoquímica, atividade antimicrobiana, inseticida e antioxidante dos extratos vegetais e óleo de Myrcia oblongata. Foram detectados a presença de saponinas, esteróides, triterpenóides, taninos e flavonóides. Os extratos apresentaram capacidade antimicrobiana sobre os microrganismos testados, exceto o extrato metanólico que não demonstrou atividade para P. mirabilis e S. Enteritidis. Quanto a análise de compostos antioxidantes observou-se que os extratos hexânico, acetato de etila e acetona apresentaram maiores atividades antioxidantes e também maior performance inseticida sobre a larva Alphitobius diaperinus e exibindo mortalidade de 80% na fase adulta. Os resultados aqui reportados mostram que pode haver uma relação entre potencial antioxidante e efeito inseticida do óleo de Myrcia oblongata; os componentes presentes tanto no extrato como o oléo podem ser utilizados como alternativa natural aos compostos sintéticos no controle biológico de parasitas e microrganismos patogênicos.
Asunto(s)
Animales , Antioxidantes/análisis , Escarabajos , Fitoterapia , Insecticidas/análisis , Myrtaceae/microbiología , Myrtaceae/química , SalmonellaRESUMEN
Microbial biofilms can cause serious health problems, since, due to their persistent character, they often function as spreaders of contaminants. Hydrolytic enzymes have a number of industrial applications and have been indicated as an alternative to the traditional chemical methods that are used to eradicate microbial biofilms. In this study, we evaluated the ability of enzymatic extracts produced by endophytic fungi isolated from the Amazonian species Myrcia guianensis to remove Staphylococcus aureus biofilms. After culture in liquid medium, the fungal hydrolytic extracts showed amylase (3.77 U/mL), lipase (3.84 U/mL), protease (3.63 U/mL), and xylanase (2.91 U/mL) activity. A 24 h mature S. aureus ATCC6538 biofilm was exposed to each enzyme extract with standardized enzyme activities for 10, 30, and 60 min. The optical density at 630 nm was used to calculate the growth rate (GR%) and the residual biofilm rate (RBR%). The most promising solutions were used in combination, based on a 24 factorial design for 0, 10, 20, and 30 min of exposure. Lipase and protease solutions, when applied separately, were the most effective, and promoted the complete removal of S. aureus biofilms in t10 (lipase) and t30 and t60 (lipase and protease). Of the combined treatments using 1.0 U/mL protease and 0.4 U/mL lipase, total biofilm degradation was observed for all exposure times. Thus, the hydrolases produced by the Amazonian endophytic fungi evaluated here are highlighted as an interesting tool in the fight against microbial biofilms.
Asunto(s)
Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Proteínas Fúngicas/farmacología , Hongos/enzimología , Péptido Hidrolasas/farmacología , Staphylococcus aureus/fisiología , Biopelículas/crecimiento & desarrollo , Myrtaceae/microbiologíaRESUMEN
Megacoelomyces (type species: Megacoelomyces sanchezii), an ascomycete asexual morph infecting Myrcia fenzliana (Myrtaceae) from the Brazilian Cerrado, is described as a new genus in the Phaeosphaeriaceae (Pleosporales, Dothideomycetes, Ascomycota), based on multilocus phylogeny (three nuclear ribosomal DNA and two protein-coding genes) in addition to morphological (light and scanning electron microscopy) and ecological data.
Asunto(s)
Clasificación , Hongos Mitospóricos , Ascomicetos/clasificación , Ascomicetos/citología , Ascomicetos/genética , Ascomicetos/ultraestructura , Brasil , ADN de Hongos/genética , ADN Ribosómico/genética , Genes Fúngicos , Microscopía Electrónica de Rastreo , Hongos Mitospóricos/clasificación , Hongos Mitospóricos/citología , Hongos Mitospóricos/genética , Hongos Mitospóricos/ultraestructura , Myrtaceae/microbiología , FilogeniaRESUMEN
Flowers produce an array of nutrient-rich exudates in which microbes can thrive, making them hotspots for microbial abundance and diversity. During a diversity study of yeasts inhabiting the flowers of Metrosideros polymorpha (Myrtaceae) in the Hawai'i Volcanoes National Park (HI, USA), five isolates were found to represent two novel species. Morphological and physiological characterization, and sequence analysis of the small subunit ribosomal RNA (rRNA) genes, the D1/D2 domains of the large subunit rRNA genes, the internal transcribed spacer (ITS) regions, and the genes encoding the largest and second largest subunits of the RNA polymerase II (RPB1 and RPB2, respectively), classified both species in the family Metschnikowiaceae, and we propose the names Candida metrosideri pro tempore sp. nov. (JK22T = CBS 16091 = MUCL 57821) and Candida ohialehuae pro tempore sp. nov. (JK58.2T = CBS 16092 = MUCL 57822) for such new taxa. Both novel Candida species form a well-supported subclade in the Metschnikowiaceae containing species associated with insects, flowers, and a few species of clinical importance. The ascosporic state of the novel species was not observed. The two novel yeast species showed elevated minimum inhibitory concentrations to the antifungal drug amphotericin B (>4 µg/mL). The ecology and phylogenetic relationships of C. metrosideri and C. ohialehuae are also discussed.
Asunto(s)
Candida/clasificación , Myrtaceae/microbiología , Anfotericina B/farmacología , Antifúngicos/farmacología , Candida/efectos de los fármacos , Candida/genética , Candida/aislamiento & purificación , Farmacorresistencia Fúngica , Flores/microbiología , Hawaii , Pruebas de Sensibilidad Microbiana , Fenotipo , Filogenia , ARN Ribosómico/clasificación , ARN Ribosómico/genética , ARN Ribosómico/metabolismoRESUMEN
Hydrogelled emulsions (HE) from chia and linseed oils (1:1) were made with different concentrations (0, 6, 8, and 10%) of jabuticaba peel extract (JPE) obtained by microwave hydrodiffusion and gravity (MHG) extraction. Burgers (20% fat) were produced with the replacement of 60% of fat by HEs. The oxidative profile and the sensory quality of raw and cooked burgers were evaluated for 120 days (-18 °C). The JPE exhibited 1.72 mg/mL of phenolic compounds and 57,741.67 µmol TE/mL of antioxidant capacity. In addition, the MHG extraction eliminated the mesophilic bacteria from the jabuticaba peel. The burgers made with HE and without the addition of JPE showed a 5-fold increase in TBARS values when compared to the control. On the other hand, the addition of 10% JPE to HE was effective to maintain the lipid oxidation similar to the control until the 60th day of storage. Besides, the incorporation of JPE into HE reduced the sensory defects caused by the lipid reformulation.
Asunto(s)
Productos de la Carne/análisis , Myrtaceae/química , Extractos Vegetales/química , Adulto , Animales , Bovinos , Color , Comportamiento del Consumidor , Culinaria , Femenino , Almacenamiento de Alimentos , Humanos , Hidrogeles/química , Aceite de Linaza , Masculino , Microondas , Persona de Mediana Edad , Myrtaceae/microbiología , Myrtaceae/efectos de la radiación , Salvia/química , Porcinos , Gusto , Sustancias Reactivas al Ácido Tiobarbitúrico/análisisRESUMEN
In Southeast Asia, primary tropical rainforests are usually dominated by ectomycorrhizal (ECM) trees belonging to Dipterocarpaceae, although arbuscular mycorrhizal trees often outcompete them after disturbances such as forest fires and clear-cutting, thus preventing dipterocarp regeneration. In some secondary tropical forests, however, potentially ECM trees belonging to Tristaniopsis (Myrtaceae) become dominant and may help ECM dipterocarp forests to recover. However, we have no information about their mycorrhizal status in these settings. In this study, we analyzed ECM fungal communities in tropical secondary forests dominated by Tristaniopsis and investigated which ECM fungal species are shared with other tropical or temperate areas. In total, 100 samples were collected from four secondary forests dominated by Tristaniopsis on Bangka Island. ECM tips in the soil samples were subjected to molecular analyses to identify both ECM and host species. Based on a >97% ITS sequence similarity threshold, we identified 56 ECM fungal species dominated by Thelephoraceae, Russulaceae, and Clavulinaceae. Some of the ECM fungal species were shared between dominant Tristaniopsis and coexisting Eucalyptus or Quercus trees, including 5 common to ECM fungi recorded in a primary mixed dipterocarp forest at Lambir Hill, Malaysia. In contrast, no ECM fungal species were shared with other geographical regions, even with Tristaniopsis in New Caledonia. These results imply that secondary tropical forests dominated by Tristaniopsis harbor diverse ECM fungi, including those that inhabit primary dipterocarp forests in the same geographical region. They may function as refugia for ECM fungi, given that dipterocarp forests are disappearing quickly due to human activity.
Asunto(s)
Bosques , Islas , Micorrizas/aislamiento & purificación , Myrtaceae/microbiología , Clima Tropical , Indonesia , Micorrizas/fisiología , ÁrbolesRESUMEN
This work evaluated nutritional and organoleptic properties of murta, a Chilean native berry, impregnated with Lactobacillus casei var. rhamnosus and dehydrated by different methods: freeze- (FD), convective- (CD) and vacuum- (VD) drying. Scanning electron microscopy revealed that L. casei localized at the peduncle and near the peduncle of the impregnated fruit. Murta enriched with probiotics contained higher L. casei viable counts after dehydration with FD compared to CD and VD methods. Overall, drying resulted in a decrease in crude fibre and phenolic compounds, which was attributed to L. casei metabolic activity suggesting that murta berries could act as prebiotics for L. casei. Among drying methods, L. casei enriched FD murta presented less alterations in the microstructure, less drying-induced damage and obtained a higher sensory acceptability score than CD and VD murta. Taken together, these results will contribute to the development of functional foods from regional products improving local economy.
Asunto(s)
Frutas/química , Lacticaseibacillus rhamnosus , Myrtaceae/química , Chile , Desecación , Fibras de la Dieta/análisis , Liofilización , Frutas/microbiología , Humanos , Lacticaseibacillus rhamnosus/crecimiento & desarrollo , Myrtaceae/microbiología , Fenoles/análisis , Prebióticos , Probióticos , Sensación , VacioRESUMEN
Volatiles compounds are involved in defensive induction against insects, playing an important role in insect-plant interaction being induced by response to mechanical damage. However, they could decrease according to the domestication degree in cultivated plants. Currently, it has been established that secondary metabolites are reduced due to the domestication process in murtilla. Hence, the follow question emerges: Are volatile organic compounds induced by mechanical damage reduced in cultivated murtilla plants in relation to wild plants? Two cultivated ecotypes and their respective wild counterparts were sampled. Volatiles compounds were obtained using Porapak-Q columns and analyzed by gas chromatography. Results showed that compounds as 2-hexanone, α-pinene, 2-thujene, 3-thujene and 1,8- cineole were more abundant in wild plants exposed to a mechanical damage than cultivated plants. Hence, these compounds have been associated to induced defense, these results suggest that domestication reduced the induction of defensive volatiles in cultivated murtilla in response to mechanical damage.
Los compuestos volaÌtiles estaÌn implicados en la defensa inducida contra insectos, desempenÌando un papel importante en esta interaccioÌn. Sin embargo, estos compuestos podriÌan disminuir seguÌn el grado de domesticacioÌn. Actualmente, se ha reportado que algunos metabolitos secundarios son reducidos en plantas de murtilla domesticadas. Por lo tanto, surge la siguiente pregunta de investigacioÌn: ¿Los compuestos orgaÌnicos volaÌtiles inducidos por el danÌo mecaÌnico son reducidos en plantas cultivadas de murtilla en comparacioÌn con plantas silvestres? Para dos ecotipos cultivados y sus respectivas contrapartes silvestres, los compuestos volaÌtiles fueron capturados usando columnas de Porapak-Q y las muestras analizadas por cromatografiÌa gaseosa. Los resultados mostraron que compuestos tales como 2- hexanona, α-pineno, 2-tujeno, 3-tujeno y 1,8-cineol fueron maÌs abundantes en plantas silvestres expuestas a danÌo mecaÌnico que en cultivadas. Debido a que estos compuestos se han asociado a defensa inducida, estos resultados sugieren que la domesticacioÌn reduce la induccioÌn de volaÌtiles en plantas cultivadas sometidas a danÌo mecaÌnico.
Asunto(s)
Animales , Aceites Volátiles/metabolismo , Myrtaceae/metabolismo , Myrtaceae/microbiología , Domesticación , Insectos/fisiología , Sesquiterpenos/análisis , Sesquiterpenos/metabolismo , Aceites Volátiles/química , Myrtaceae/química , Monoterpenos/análisis , Monoterpenos/metabolismo , Vida Silvestre , Larva/fisiología , Cromatografía de Gases y Espectrometría de MasasRESUMEN
Inoculation of arbuscular mycorrhizal fungi (AMF) as plant growth promoters has mostly been conducted using single-species inoculum. In this study, we investigated whether co-inoculation of different native AMF species induced an improvement of plant growth in an ultramafic soil. We analyzed the effects of six species of AMF from a New Caledonian ultramafic soil on plant growth and nutrition, using mono-inoculations and mixtures comprising different numbers of AMF species, in a greenhouse experiment. The endemic Metrosideros laurifolia was used as a host plant. Our results suggest that, when the plant faced multiple abiotic stress factors (nutrient deficiencies and high concentrations of different heavy metals), co-inoculation of AMF belonging to different families was more efficient than mono-inoculation in improving biomass, mineral nutrition, Ca/Mg ratio, and tolerance to heavy metals of plants in ultramafic soil. This performance suggested functional complementarity between distantly related AMF. Our findings will have important implications for restoration ecology and mycorrhizal biotechnology applied to ultramafic soils.
Asunto(s)
Inoculantes Agrícolas/fisiología , Producción de Cultivos/métodos , Glomeromycota/fisiología , Micorrizas/fisiología , Myrtaceae/crecimiento & desarrollo , Glomeromycota/clasificación , Micorrizas/clasificación , Myrtaceae/microbiología , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/microbiologíaRESUMEN
OBJECTIVES: The aim of this study was to report the draft genome sequence of a multidrug-resistant (MDR) Escherichia coli isolate obtained from a jaboticaba (Plinia cauliflora) culture soil in Brazil. METHODS: The whole genome of E. coli strain S376 was sequenced on an Illumina MiSeq platform and was assembled using SPAdes v.3.9. All data analyses were performed using tools from the Center for Genomic Epidemiology and Geneious v.11.1.5 software. The genome was annotated using the NCBI Prokaryotic Genome Annotation Pipeline (PGAP) v.3.2. RESULTS: A total of 4854 protein-coding sequences were identified, with a GC content of 50.4%. Resistome analysis showed acquired antimicrobial resistance genes to ß-lactams (blaTEM-116), tetracyclines [tetA and tet(34)], aminoglycosides (aadA1), trimethoprim (dfrA1) and macrolides (mphA). Mutations in the quinolone resistance-determining region (QRDR) of GyrA, ParC and ParE were detected. Three plasmid incompatibility groups were detected [IncFII (allele 24), IncFIB (allele 1) and ColRNAl]. In silico analysis showed the tetA and mphA are located inside the IncF plasmid. This isolate was classified as ST906 (singleton), serotype O156:H23-fimH61, commensal phylogroup B1 and presented various virulence genes, including iroN, ipfA, cma, gad and iss. CONCLUSION: This is the first report of a draft genome sequence of a MDR E. coli ST906 serotype O156:H23-fimH61 obtained from a Brazilian soil. This draft genome sequence can be used to compare MDR E. coli isolated from different sources and to better understand the spread of this clone worldwide.
Asunto(s)
Farmacorresistencia Bacteriana Múltiple/genética , Escherichia coli/genética , Genoma Bacteriano , Myrtaceae/microbiología , Microbiología del Suelo , Brasil , Proteínas de Escherichia coli/genética , Plásmidos , Virulencia , Secuenciación Completa del GenomaRESUMEN
Two new polyketide metabolites, the 12-membered macrolides 4-hydroxy-12-methyloxacyclododecane-2,5,6-trione (1) and 12-methyloxacyclododecane-2,5,6-trione (2), were isolated from the endophytic fungal strain Cladosprium colocasiae A801 of the plant Callistemon viminalis, together with five known derivatives. Their structures were fully characterized by means of detailed spectroscopic analysis for new structures, and in comparison with published data for known compounds. The antibacterial, cytotoxic, and α-glucosidase inhibitory activities of the new compounds 1 and 2 were evaluated.
Asunto(s)
Ascomicetos/química , Endófitos/química , Macrólidos/química , Myrtaceae/química , Antibacterianos/química , Antibacterianos/farmacología , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/farmacología , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/farmacología , Bacterias/efectos de los fármacos , Línea Celular Tumoral , Ensayos de Selección de Medicamentos Antitumorales , Fermentación , Glucosidasas/antagonistas & inhibidores , Humanos , Macrólidos/farmacología , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Myrtaceae/microbiologíaRESUMEN
There is increasing concern about tree mortality around the world due to climatic extremes and associated shifts in pest and pathogen dynamics. Yet, empirical studies addressing the interactive effect of biotic and abiotic stress on plants are very rare. Therefore, in this study, we examined the interaction between drought stress and a canker pathogen, Quambalaria coyrecup, on the eucalypt - Corymbia calophylla (marri), which is experiencing increasing drought stress. We hypothesized that drought stress would increase marri's susceptibility to canker disease, and cankers would have the largest negative effect on plants that are already drought stressed before pathogen inoculation. To test the hypotheses, in a glasshouse, marri saplings were exposed to drought either before or after pathogen inoculation, or were well-watered or droughted throughout the experiment either with or without inoculation. Canker development was greater in well-watered saplings than in droughted saplings, with the fastest development occurring in well-watered saplings that had experienced drought stress before inoculation. Irrespective of water treatments, marri saplings employed phenol-based localized biochemical defence against the pathogen. Drought reduced photosynthesis and growth, however, a negative effect of canker disease on saplings' physiological performance was only observed in well-watered saplings. In well-watered saplings, canker-induced loss of sapwood function contributed to reduced whole-plant hydraulic conductance, photosynthesis and growth. The results provide evidence that timing of drought stress influences host physiology, and host condition influences canker disease susceptibility through differences in induced biochemical defence mechanisms. The observations highlight the importance of explicitly incorporating abiotic and biotic stress, as well as their interactions, in future studies of tree mortality in drought-prone regions worldwide.
Asunto(s)
Basidiomycota , Sequías , Myrtaceae/microbiología , Enfermedades de las Plantas/microbiología , Árboles/microbiología , Interacciones Huésped-Patógeno , Myrtaceae/crecimiento & desarrollo , Estrés Fisiológico , Árboles/crecimiento & desarrolloRESUMEN
The ecological restauration of nickel mining-degraded areas in New Caledonia is strongly limited by soil mineral nutrient deficiencies, heavy metal toxicity and slow growth rate of the native plant species. The improvement of revegetation technics needs multidisciplinary knowledge. A field experiment with relocated topsoil was assessed to test plant inoculation with a mix of three selected arbuscular mycorrhizal fungi (AMF) combined with sewage sludge amendment of the soil. Metrosideros laurifolia seedlings, an endemic Myrtaceae, were inoculated with the mixed AMF isolates and grown in a nursery for 18â¯months before being planted. 528â¯days after plantation, the dry weight of inoculated plants was 4 times higher than non-inoculated ones. AMF inoculated plants growing in sewage sludge amended soil showed a dry weight more than seven times higher than control plants. These differences were positively correlated with mycorrhizal colonization. However at this stage, AMF inoculated isolates were reduced in roots of M. laurifolia and replaced by several AMF indigenous species. This AMF diversity was higher in inoculated plants and in non-amended plots. Inoculated plants were characterized by a better mineral nutrition, a higher Ca/Mg ratio and a lower heavy metal translocation. In conclusion, this study showed that AMF inoculation combined with sewage sludge amendment of soil can improve ecological restoration of ultramafic mine-degraded areas.
Asunto(s)
Fertilizantes/análisis , Micorrizas/fisiología , Myrtaceae/crecimiento & desarrollo , Aguas del Alcantarillado/análisis , Microbiología del Suelo , Myrtaceae/efectos de los fármacos , Myrtaceae/microbiología , Nueva Caledonia , Plantones/efectos de los fármacos , Plantones/crecimiento & desarrollo , Plantones/microbiología , Suelo/químicaRESUMEN
It is challenging to sequence and assemble genomes of obligate plant pathogens and microorganisms because of limited amounts of DNA, comparatively large genomes and high numbers of repeat regions. We sequenced the 1.2 gigabase genome of an obligate rust fungus, Austropuccinia psidii, the cause of rust on Myrtaceae, with a Chromium 10X library. This technology has mostly been applied for single-cell sequencing in immunological studies of mammals. We compared scaffolds of a genome assembled from the Chromium library with one assembled from combined paired-end and mate-pair libraries, sequenced with Illumina HiSeq. Chromium 10X provided a superior assembly, in terms of number of scaffolds, N50 and number of genes recovered. It required less DNA than other methods and was sequenced and assembled at a lower cost. Chromium sequencing could provide a solution to sequence and assemble genomes of obligate plant pathogens where the amount of available DNA is a limiting factor.
Asunto(s)
Basidiomycota/genética , ADN de Hongos/genética , Genoma Fúngico , Genómica/métodos , Myrtaceae/microbiología , Enfermedades de las Plantas/microbiología , Análisis de Secuencia de ADN/métodos , Cromo/química , ADN de Hongos/análisis , Biblioteca de GenesRESUMEN
Austropuccinia psidii (myrtle rust) is a globally invasive neotropical rust of the Myrtaceae that came into international prominence following extensive damage to exotic Eucalyptus plantations in Brazil in the 1970s and 1980s. In 2005, myrtle rust established in Hawaii (USA), and over the past 12 years has spread from the Americas into Asia, the Pacific, and South Africa. Myrtle rust was detected in Australia in 2010, and the response and ultimately unsuccessful eradication attempt was a lesson to those concerned about the threat of exotic pests and diseases to Australia's environment. Seven years following establishment, we are already observing the decline of many myrtaceous species and severe impacts to native plant communities. However, the recently developed Myrtle rust in Australia draft action plan identified that there is no nationally coordinated response strategy for the environmental dimensions of this threat. Recent reviews have identified a greater need for involvement from environmental agencies in biosecurity preparedness, response, and resourcing, and we believe this approach needs to extend to the management of invasive environmental pathogens once they establish.
Asunto(s)
Basidiomycota/fisiología , Myrtaceae/microbiología , Enfermedades de las Plantas/prevención & control , Australia , Biota , Enfermedades de las Plantas/microbiologíaRESUMEN
Ceratocystis lukuohia and C. huliohia are recently described fungal species that cause rapid 'ohi'a death (ROD) of Metrosideros polymorpha, Hawaii's most abundant and ecologically important native species. Although the pathogens are now widespread on Hawai'i Island, a major effort is underway to study and manage affected forests, and particularly to prevent the disease from spreading to other islands in the State or throughout the Pacific. Rapid and accurate detection is critical. Molecular diagnostic real-time PCR protocols were developed to detect and distinguish the two pathogens, suitable for detection of fungal DNA from extracts of wood, soil, and insect frass. The assays detect as few as 2 to 4 or 16 spores of C. huliohia or C. lukuohia, respectively. These assays are valuable tools for monitoring disease spread and offer a significant advantage over culture-based methods for diagnostics, requiring <1 day to arrive at definitive results.
Asunto(s)
Ascomicetos/aislamiento & purificación , Myrtaceae/microbiología , Enfermedades de las Plantas/microbiología , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Ascomicetos/clasificación , Ascomicetos/genética , Cartilla de ADN/genética , ADN de Hongos/genética , Fertilizantes/microbiología , Bosques , Hawaii , Reproducibilidad de los Resultados , Microbiología del Suelo , Factores de Tiempo , Madera/microbiologíaRESUMEN
BACKGROUND: Jabuticaba (Myrciaria jaboticaba) is a Brazilian fruit rich in phenolic compounds and much appreciated for its sweet and slightly tangy taste. However, the high perishability of this fruit impairs its economic exploitation, creating an opportunity for the development of innovative products, such as high hydrostatic pressure (HHP) processed juices. We investigated the effect of HHP (200, 350 and 500 MPa for 5, 7.5 and 10 min) on phenolic compounds, antioxidant activity and microbiological quality of jabuticaba juice and the effect of the most effective HHP condition on its sensory acceptance. RESULTS: Pressurization increased total phenolic compound content (up to 38%) and antioxidant activity by FRAP assay (up to 46%), probably by increasing phenolic compound extractability due to tissue damage. Pressurization progressively decreased microbial counts, and colony growth was undetectable at pressures of 350 MPa or 500 MPa. With the exception of aroma, which was 10% lower in pressurized juice at 350 MPa for 7.5 min in relation to unprocessed juice, HHP did not affect sensory acceptance scores. CONCLUSION: Our results show that HHP was effective in ensuring microbiological quality, increasing bioactive potential and maintaining overall acceptance of jabuticaba juice, reinforcing the potential application of this processing technology in bioactive-rich foods. © 2017 Society of Chemical Industry.
Asunto(s)
Bacterias/aislamiento & purificación , Manipulación de Alimentos/métodos , Jugos de Frutas y Vegetales/análisis , Frutas/química , Myrtaceae/química , Fenoles/análisis , Bacterias/clasificación , Bacterias/genética , Bacterias/crecimiento & desarrollo , Brasil , Contaminación de Alimentos/análisis , Manipulación de Alimentos/instrumentación , Frutas/microbiología , Jugos de Frutas y Vegetales/microbiología , Humanos , Presión Hidrostática , Myrtaceae/microbiología , GustoRESUMEN
In April 2010, Austropuccinia psidii (formerly Puccinia psidii) was detected for the first time in Australia on the central coast of New South Wales. The fungus spread rapidly along the east coast and can now be found infecting vegetation in a range of native forest ecosystems with disease impacts ranging from minor leaf spots to severe shoot and stem blight and tree dieback. Localised extinction of some plant species has been recorded. In 2014, the impact of A. psidii was observed for the first time in a wet sclerophyll site with a rainforest understory, dominated by species of Myrtaceae, in Tallebudgera Valley, south east Queensland, Australia. This study aimed to determine the impact of A. psidii on individual species and species composition. Here we provide quantitative and qualitative evidence on the significant impact A. psidii has in native ecosystems, on a broader range of species than previously reported. Archirhodomyrtus beckleri, Decaspermum humile, Gossia hillii and Rhodamnia maideniana are in serious decline, with significant increases in tree mortality over the period of our study. This research further highlights the potential of this invasive pathogen to negatively impact native ecosystems and biodiversity.