Detection of silver nanoparticles inside leaf of European beech (Fagus sylvatica L.)

In a greenhouse experiment, silver nanoparticles (Ag-NPs) were applied on European beech (Fagus sylvatica L.) leaves using the droplet application method. Scanning electron microscopy (SEM) analyses showed that after 24 h silver nanoparticles were mostly present in aggregates or as single particles on the surface of the leaf, surrounding or covering the stomata. Analyses of cross sections of the leaf revealed that some silver nanoparticles were adhering to the cell walls of the mesophyll and palisade cells, most likely after penetration into the leaf through the stomata as particles and not as Ag ions. Our preliminary results showed evidence of foliar uptake of silver nanoparticles in European beech. This opens new insights on the ability of trees to take up solid nanosized particles, eventually contained in raindrops, through their leaves, and potentially transport them to other parts of the tree. This study would be helpful for investigating the role of trees in atmospheric ultrafine particle mitigation

Single stranded adeno-associated virus achieves efficient gene transfer to anterior segment in the mouse eye

Adeno-associated viruses (AAVs) are used extensively as a gene delivery vehicle for retinal gene therapy, yet its ability to target the anterior segment of the eye, critical to unlocking therapeutic opportunities, is less characterized. Previously, self-complimentary (sc) AAV was shown to be necessary for transduction of the cornea and trabecular meshwork (TM), limiting the size of the gene transfer cassette, likely due to a block in second strand synthesis thought to be required for functional transduction. Here, we evaluated several AAV capsids in a single stranded (ss) genome conformation for their ability to overcome the need for scAAV for targeting corneal endothelium and TM. AAV2, 8, and a recently synthetically developed AAV called Anc80L65 were evaluated in vitro and in vivo by intracameral injection in mice. Results show that although scAAV2 demonstrated superior infectivity in vitro including Human Trabecular meshwork (HTM) immortalized cell lines; Anc80L65 transduced following a single intracameral injection efficiently all components of the mouse anterior segment, including the TM, corneal stroma, and endothelial cells. These results suggest that Anc80L65 is able to overcome the requirement for scAAV genomes to enable TM and corneal targeting, expanding the potential experimental and therapeutic use of AAV gene transfer in the anterior segment of the eye

Spatiotemporal organisation of protein processing in the kidney

The kidney regulates plasma protein levels by eliminating them from the circulation. Proteins filtered by glomeruli are endocytosed and degraded in the proximal tubule and defects in this process result in tubular proteinuria, an important clinical biomarker. However, the spatiotemporal organization of renal protein metabolism in vivo was previously unclear. Here, using functional probes and intravital microscopy, we track the fate of filtered proteins in real time in living mice, and map specialized processing to tubular structures with singular value decomposition analysis and three-dimensional electron microscopy. We reveal that degradation of proteins requires sequential, coordinated activity of distinct tubular sub-segments, each adapted to specific tasks. Moreover, we leverage this approach to pinpoint the nature of endo-lysosomal disorders in disease models, and show that compensatory uptake in later regions of the proximal tubule limits urinary protein loss. This means that measurement of proteinuria likely underestimates severity of endocytotic defects in patients

Detection of silver nanoparticles inside leaf of European beech (Fagus sylvatica L.)

In a greenhouse experiment, silver nanoparticles (Ag-NPs) were applied on European beech (Fagus sylvatica L.) leaves using the droplet application method. Scanning electron microscopy (SEM) analyses showed that after 24 h silver nanoparticles were mostly present in aggregates or as single particles on the surface of the leaf, surrounding or covering the stomata. Analyses of cross sections of the leaf revealed that some silver nanoparticles were adhering to the cell walls of the mesophyll and palisade cells, most likely after penetration into the leaf through the stomata as particles and not as Ag ions. Our preliminary results showed evidence of foliar uptake of silver nanoparticles in European beech. This opens new insights on the ability of trees to take up solid nanosized particles, eventually contained in raindrops, through their leaves, and potentially transport them to other parts of the tree. This study would be helpful for investigating the role of trees in atmospheric ultrafine particle mitigation

Infestación natural y daños ocasionados por la “isoca de la espiga del maíz”, en híbridos Bt sembrados en fechas tardías

Entre las plagas que afectan a las espigas de maíz, Helicoverpa zea, es considerada como la más importante. Esta especie se destaca por desarrollar varias generaciones, por lo cual sus poblaciones son crecientes de siembra a cosecha. En consecuencia, las siembras de maíces de segunda y/o en fechas tardías, son afectadas en mayor medida, registrando un mayor porcentaje de espigas infestadas y daños más severos. Entre las estrategias para reducirlos, existen híbridos de que expresan genes de la bacteria Bacillus thuringiensis (Bt) que codifican proteínas tóxicas Cry (Crystal). Durante el ciclo agrícola 2017-2018, se evaluó la infestación natural y los daños ocasionados por la “isoca de la espiga del maíz” en híbridos Bt que expresan proteínas toxinas Cry, sembrados tardíamente. Se discutirán los resultados obtenidos y se plantearán recomendaciones de manejo en base a los resultados de este trabajo y la experiencia desarrollada por el grupo de investigación Zoología Agrícola y Diversidad Animal.EEA BalcarceFil: Franco, María del Rocío. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Tulli, María Celia. Instituto Nacional de Tecnología Agropecuaria. (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Tulli, María Celia. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Martiarena, Diego Andrés. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Martiarena, Diego Andrés. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Divita, Ignacio Federico. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Divita, Ignacio Federico. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Mateos Inchauspe, Facundo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Mateos Inchauspe, Facundo. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Carmona, Dora Mabel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Carmona, Dora Mabel. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina

Gorgojos plaga en girasol: daño de Listroderes sp. en estadios iniciales de cultivo

El cultivo de girasol es afectado por diversas plagas, entre las cuales se encuentran especies del género Listroderes, conocidos vulgarmente como “gorgojos del girasol”, que afectan al cultivo durante las primeras etapas de su desarrollo. En el ciclo 2019-2020 este insecto se destacó por ocasionar pérdidas de importancia en el stand de plantas de girasol. Los adultos ocasionaron daños a nivel del cuello de la planta, y según su estadio de desarrollo vegetativo, ocasionaron su corte o estrangulamiento, en este último caso seguido por vuelco y posterior muerte. La magnitud de los daños ocasionados se reflejó en la necesidad de resiembra total o parcial en varios lotes de girasol del sudeste de la provincia de Buenos Aires.EEA BalcarceFil: Tulli, María Celia. Instituto Nacional de Tecnología Agropecuaria. (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Tulli, María Celia. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Del Río, María Guadalupe. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina.Fil: Del Río, María Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Martiarena, Diego Andrés. Instituto Nacional de Tecnología Agropecuaria. (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Martiarena, Diego Andrés. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Mateos Inchauspe, Facundo. Instituto Nacional de Tecnología Agropecuaria. (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Mateos Inchauspe, Facundo. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Divita, Ignacio Federico. Instituto Nacional de Tecnología Agropecuaria. (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Divita, Ignacio Federico. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Carmona, Dora Mabel. Instituto Nacional de Tecnología Agropecuaria. (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Carmona, Dora Mabel. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina

Daños ocasionados por el gorgojo Listroderes foveatus (Coleoptera: Curculionidae) en cultivos de girasol del sudeste de Buenos Aires (Argentina)

El cultivo del girasol es afectado por insectos plaga en sus diferentes estadios de desarrollo vegetativo. Entre estos, se encuentra un complejo coleópteros del género Listroderes Schoenhere conocidos vulgarmente como “gorgojos del girasol”. Los adultos afecta al cultivo en las primeras etapas de su desarrollo. Durante el ciclo agrícola 2019-2020, adultos de especie Listroderes Foveatus (Lea) causaron pérdidas significativas en la densidad de plantas logradas de girasol, en varios cultivos de la región del sudoeste de la provincia de Buenos Aires. Se registraron daños a nivel de la base de la plantas y, dependiendo del desarrollo de su estado vegetativo, los gorgojos ocasionaron corte y estrangulamiento seguido por vuelco y posterior muerte. La magnitud de los daños producidos se reflejó en la necesidad de resiembra parcial o total en varios lotes de girasol.Sunflowers are attacked by insect pests at various stages of crop development. Among them there is a complex of species of Coleoptera order, genus Listroderes Schoenherr, commonly known as “sunflower weevils”. The adults affect the crop at the early stages of its development. During 2019-2020 growing season, adult of Listroderes foveatus (Lea) species caused significant losses in the sunflower plant stand, in several sunflower plots of the southeastern region of Buenos Aires province. Damage at basal level of the plant stem was registered. Depending on the vegetative development stage, they caused their cut or strangulation, followed by overturning and subsequent death. The magnitude of the damage caused was reflected in the need for total or partial resowing in several sunflower plots.EEA BalcarceFil: Tulli, María Cecilia. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Martiarena, Diego. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Divita, Ignacio. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Mateos Inchauspe, Facundo. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Carmona, Dora. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Del Río, María. Universidad de La Plata. Facultad de Ciencias Naturales y Museo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Correlative super-resolution and electron microscopy to resolve protein localization in zebrafish retina

We present a method to investigate the subcellular protein localization in the larval zebrafish retina by combining super-resolution light microscopy and scanning electron microscopy. The sub-diffraction limit resolution capabilities of super-resolution light microscopes allow improving the accuracy of the correlated data. Briefly, 110 nanometer thick cryo-sections are transferred to a silicon wafer and, after immunofluorescence staining, are imaged by super-resolution light microscopy. Subsequently, the sections are preserved in methylcellulose and platinum shadowed prior to imaging in a scanning electron microscope (SEM). The images from these two microscopy modalities are easily merged using tissue landmarks with open source software. Here we describe the adapted method for the larval zebrafish retina. However, this method is also applicable to other types of tissues and organisms. We demonstrate that the complementary information obtained by this correlation is able to resolve the expression of mitochondrial proteins in relation with the membranes and cristae of mitochondria as well as to other compartments of the cell