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Abstract: Grapevine yellows is one of the most damaging phytoplasma-associated diseases worldwide. It is linked to several phytoplasma species, which can vary regionally due to phytoplasma and insect-vector diversity. Specific, rapid, and reliable detection of the grapevine yellows pathogen has an important role in phytoplasma control. The purpose of this study was to develop and validate a specific loop-mediated isothermal amplification (LAMP) assay for detection of a distinct strain of grapevine ‘Candidatus Phytoplasma asteris’ that is present in South Africa, through implementation of a genome-informed test design approach. Several freely available, user-friendly, web-based tools were coupled to design the specific LAMP assays. The criteria for selection of the assays were set for each step of the process, which resulted in four experimentally operative LAMP assays that targeted the ftsH/hflB gene region, specific to the aster yellows phytoplasma strain from South Africa. A real-time PCR was developed, targeting the same genetic region, to provide extensive validation of the LAMP assay. The validated molecular assays are highly specific to the targeted aster yellows phytoplasma strain from South Africa, with good sensitivity and reproducibility. We show a genome-informed molecular test design and an efficient validation approach for molecular tests if reference and sample materials are sparse and hard to obtain.
Keywords: aster yellows, fruit, LAMP, molecular detection, pathogendetection, phytoplasma, Prokaryotes
Published in DiRROS: 17.07.2024; Views: 316; Downloads: 195
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Abstract: Abstract As a result of the COVID-19 pandemic, many new materials and masks came onto the market. To determine their suitability, several standards specify which properties to test, including bacterial filtration efficiency (BFE), while none describe how to determine viral filtration efficiency (VFE), a property that is particularly important in times of pandemic. Therefore, we focused our research on evaluating the suitability and efficiency of different systems for determining VFE. Here, we evaluated the VFE of 6 mask types (e.g., a surgical mask, a respirator, material for mask production, and cloth masks) with different filtration efficiencies in four experimental setups and compared the results with BFE results. The study included 17 BFE and 22 VFE experiments with 73 and 81 mask samples tested, respectively. We have shown that the masks tested had high VFE (>99% for surgical masks and respirators, ≥98% for material, and 87–97% for cloth masks) and that all experimental setups provided highly reproducible and reliable VFE results (coefficient of variation < 6%). Therefore, the VFE tests described in this study can be integrated into existing standards for mask testing.
Keywords: face masks, virus filtration efficiency, bacterial filtration efficiency, EN 14683:2019+AC:2019, air sampler
Published in DiRROS: 17.07.2024; Views: 309; Downloads: 180
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Abstract: The use of modern irrigation systems and monitoring of soil water status can help improve crop performance and water use efficiency. The influence of different irrigation treatments on soil water content dynamics and olive oil yield was studied over two growing seasons using a surface drip irrigation system in an olive grove in northern Mediterranean climate. Irrigation treatments included optimal irrigation, sustained deficit irrigation (33 % of optimal irrigation), and rainfed treatment. Based on the water applied, we calculated the percentage of replenished estimated evapotranspiration (ETc*) for each treatment using the Penman-Monteith method. Soil water content dynamics were monitored with capacitive probes at five depths (10 to 50 cm). The increase in soil water content at a depth of 30 to 50 cm, which was only achieved with optimal irrigation, resulted in a significantly higher olive oil yield. In contrast, deficit irrigation, despite the addition of water, did not lead to an increase in soil water in the layers below 30 cm, so that the yield was equal to that of rainfed treatment. In irrigated olive groves, it is beneficial to monitor the water content of the soil at several depths to ensure that a sufficient amount of water has been applied.Uporaba sodobnih namakalnih sistemov ter spremljanje stanja vode v tleh lahko pripomore k izboljšanju učinkovitosti rastlinske pridelave in rabe vode. Vpliv različnih načinov namakanja na dinamiko vsebnosti vode v tleh in pri-delek oljčnega olja smo preučevali v dveh rastnih dobah z upo-rabo površinskega kapljičnega namakalnega sistema v oljčnem nasadu v severnem sredozemskem podnebju. Obravnavanja so vključevala optimalno namakanje, trajno namakanje s priman-jkljajem (33 % optimalnega namakanja) in brez namakanja. Na podlagi porabljene vode smo z uporabo metode Penman-Mon-teith izračunali odstotek nadomeščene ocenjene evapotranspi-racije (ETc*) za vsako obravnavo. Dinamiko vsebnosti vode v tleh smo spremljali s kapacitivnimi merilniki na petih globinah (od 10 do 50 cm). Povečanje vsebnosti vode v tleh na globini od 30 do 50 cm, ki je bilo doseženo le z optimalnim namakanjem, je povzročilo večji pridelek oljčnega olja. Nasprotno pa se pri namakanju s primanjkljajem kljub dodajanju vode ni povečala količina vode v tleh v plasteh pod 30 cm, zato je bil pridelek enak pridelku brez namakanja. V namakanih oljčnih nasadih je koristno spremljati vsebnost vode v tleh na več globinah, da se zagotovi, da je bila priskrbljena zadostna količina vode
Keywords: diviner, evapotranspiration, irrigation management, olive, soil depths, volumetric soil water content
Published in DiRROS: 17.07.2024; Views: 265; Downloads: 278
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Abstract: Edible jellyfish are a traditional Southeast Asian food, usually prepared as a rehydrated product using a salt and alum mixture, whereas they are uncommon in Western Countries and considered as a novel food in Europe. Here, a recently developed, new approach for jellyfish processing and stabilization with calcium salt brining was upgraded by modifying the pre-treatment step of freshly caught jellyfish and successfully applied to several edible species. Treated jellyfish obtained by the application of the optimized version of this method respected both quality and safety parameters set by EU law, including no pathogenic microorganisms, absence or negligible levels of histamine and of total volatile basic nitrogen, no heavy metals; and the total bacterial, yeast, and mold counts were either negligible or undetectable. Jellyfish treated by the presented method exhibited unique protein content, amino acid and fatty acid profiles, antioxidant activity, and texture. The optimized method, initially set up on Rhiszostoma pulmo, was also successfully applied to other edible jellyfish species (such as Cotylorhiza tuberculata, Phyllorhiza punctata, and Rhopilema nomadica) present in the Mediterranean Sea. This study discloses an innovative process for the preparation of jellyfish-based food products for potential future distribution in Europe.
Keywords: jellyfish, novel food, safety, quality, nutritional traits, organic calcium salts
Published in DiRROS: 17.07.2024; Views: 299; Downloads: 212
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Abstract: Plant biofactories are a promising platform for sustainable production of high-value compounds, among which are insect sex pheromones, a green alternative to conventional insecticides in agriculture. Recently, we have constructed transgenic Nicotiana benthamiana plants (“Sexy Plants”, SxP) that successfully produce a blend of moth (Lepidoptera) sex pheromone compounds (Z)-11-hexadecen-1-ol and (Z)-11-hexadecenyl acetate. However, efficient biosynthesis of sex pheromones resulted in growth and developmental penalty, diminishing the potential for commercial use of SxP in biomanufacturing. To gain insight into the underlying molecular responses, we analysed the whole-genome transcriptome and evaluated it in relation to growth and pheromone production in low- and high-producing transgenic plants of v1.0 and v1.2 SxP lines. In our study, high-producing SxPv1.2 plants accumulated the highest amounts of pheromones but still maintained better growth compared to v1.0 high producers. For an in-depth biological interpretation of the transcriptomic data, we have prepared a comprehensive functional N. benthamiana genome annotation as well as gene translations to Arabidopsis thaliana, enabling functional information transfer by using Arabidopsis knowledge networks. Differential gene expression analysis, contrasting pheromone producers to wild-type plants, revealed that while only a few genes were differentially regulated in low-producing plants, high-producing plants exhibited vast transcriptional reprogramming. They showed signs of stress-like response, manifested as downregulation of photosynthesis-related genes and significant differences in expression of hormonal signalling and secondary metabolism-related genes, the latter presumably leading to previously reported volatilome changes. Further network analyses confirmed stress-like response with activation of jasmonic acid and downregulation of gibberellic acid signalling, illuminating the possibility that the observed growth penalty was not solely a consequence of a higher metabolic burden imposed upon constitutive expression of a heterologous biosynthetic pathway, but rather the result of signalling pathway perturbation. Our work presents an example of comprehensive transcriptomic analyses of disadvantageous stress signalling in N. benthamiana biofactory that could be applied to other bioproduction systems.
Keywords: transcriptomics, plant biotechnology, jasmonic acid, growthstress tradeoffs, network analysis, growth penalty, insect sex pheromone
Published in DiRROS: 17.07.2024; Views: 366; Downloads: 218
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