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Silica (SiO2) particles are widely used in various industries due to their chemical inertness, thermal stability, and wear resistance. The present study describes the preparation and potential use of porous hydrophobic and hydrophilic SiO2 microcapsules (MCs) of a narrow size distribution. First, various layers of SiO2 micro/nano-particles (M/NPs) were grafted onto monodispersed polystyrene (PS) microspheres of a narrow size distribution. Hydrophobic and hydrophilic sintered SiO2 MCs were then prepared by removing the core PS from the PS/SiO2 core–shell microspheres by burning off under normal atmospheric conditions or organic solvent dissolution, respectively. We examined how the size and quantity of the SiO2 M/NPs influence the MC's properties. Additionally, we utilized two forms of hollow SiO2 MC for different applications; one form was incorporated into polymer films, and the other was free-floating. The hydrophobic microcapsules filled with 6% hydrogen peroxide were effective in killing the tomato brown rugose fruit virus (ToBRFV). The hydrophilic microcapsules filled with thymol and thin coated onto polypropylene films were successfully used to prevent mold formation for hay protection. [ABSTRACT FROM AUTHOR]

High cannabidiol‐containing plants of Cannabis sativa (high‐CBD) growing in farms in Israel displayed foliar symptoms of interveinal chlorosis and yellowing, brittleness and occasionally necrosis. These symptoms, which were more apparent in older leaves, resembled those caused by the crinivirus lettuce chlorosis virus (LCV). However, this virus was not detected by reverse transcription (RT)‐PCR using specific primer sets. High‐throughput sequencing of viral RNA extracted from symptomatic leaves revealed the presence of cucurbit chlorotic yellows virus (CCYV), a crinivirus in the Closteroviridae family. The complete viral genome sequence was obtained using RT‐PCR followed by Sanger sequencing. The two CCYV RNA genomic segments shared 99.5%–99.85% nucleotide sequence identity with CCYV isolates from the GenBank. The virus was transmitted from symptomatic cannabis leaves to healthy plants of cannabis and Cucumis sativus 'King Star' (cucumber) by the whitefly Bemisia tabaci Middle Eastern Asia Minor 1 (MEAM1) species, causing disease symptoms identical to those of the donor plants. Cannabis‐CCYV was also transmitted between infected cucumber plants and cannabis seedlings of unknown genotype. Severe disease symptoms of yellowing and leaf‐edge necrosis were observed on high‐CBD and high Δ9‐tetrahydrocannabinol‐containing (high‐THC) flowering cannabis plants and were associated with mixed infections of LCV and CCYV. To the best of our knowledge, this is the first report of CCYV infecting C. sativa plants. [ABSTRACT FROM AUTHOR]

The soil‐borne virus known as tomato brown rugose fruit virus (ToBRFV) has a low rate of around 3% soil‐mediated infection when the soil has root debris from a previous 30–50 day development cycle of tomato plants infected with ToBRFV. This study presents anti‐viral coating formulations based on Pickering emulsion. The coating formulation is based on water‐in‐canola oil emulsions stabilized using commercial hydrophobic silica, with water‐soluble polymer (sodium polyacrylic acid). The structure of the emulsions and their stability were characterized by confocal microscopy, centrifugal analysis using a LUMiSizer®, used to confirm the emulsion stability. We tested a few different silica concentration‐based formulations, which were prepared with or without the addition of various virus disinfectants. We found that under conditions of 100% soil‐mediated ToBRFV infection of uncoated positive control plants, root‐coating with formulations based on silica Pickering emulsion were prepared with the disinfectant chlorinated‐trisodium phosphate (TSP‐Cl) showed low percentages of soil‐mediated ToBRFV infection. These formulations had no adverse effect on plant growth parameters when compared to negative control plants grown under non ToBRFV inoculation conditions. [ABSTRACT FROM AUTHOR]

Combined infection of the host plant with pathogens involving different parasitic lifestyles may result in synergistic effects that intensify disease symptoms. Understanding the molecular dynamics during concurrent infection provides essential insight into the host response. The transcriptomic pattern of cucumber plants infected with a necrotrophic pathogen, Pythium spinosum, and a biotrophic pathogen, Cucumber green mottle mosaic virus (CGMMV) was studied at different time points, under regimes of single and co-infection. Analysis of CGMMV infection alone revealed a mild influence on host gene expression at the stem base, while the infection by P. spinosum is associated with drastic changes in gene expression. Comparing P. spinosum as a single infecting pathogen with a later co-infection by CGMMV revealed a rapid host response as early as 24 hours post-CGMMV inoculation with a sharp downregulation of genes related to the host defense mechanism against the necrotrophic pathogen. Suppression of the defense mechanism of co-infected plants was followed by severe stress, including 30% plants mortality and an increase of the P. spinosum hyphae. The first evidence of defense recovery against the necrotrophic pathogen only occurred 13 days post-viral infection. These results support the hypothesis that the viral infection of the Pythium pre-infected plants subverted the host defense system and changed the equilibrium obtained with P. spinosum. It also implies a time window in which the plants are most susceptible to P. spinosum after CGMMV infection. [ABSTRACT FROM AUTHOR]