1,721,078 research outputs found
Iron deficiency effects on phytoplasma distribution in Catharanthus roseus L. plants and host tissue ultrastructural alterations
No full text
Comparative analyses of three grapevine Pinot gris virus cDNA clones reveal insights into the pathological properties of different phylogroups
Full text linkGrapevine Pinot gris virus (GPGV) is an emerging grapevine virus associated with grapevine leaf mottling and deformation (GLMD) disease. Being a recently identified virus, the molecular biology, pathological properties, and etiological complexity of GPGV remain poorly studied. Previous research revealed that GPGV comprises genetically different variants, some encoding a larger movement protein (MP) and others a shorter MP due to a C/T polymorphic site in ORF2 encoding MP. Variants that encode the shorter MP are associated with severe disease, whereas variants encoding the longer MP are associated with mild or no symptoms. However, this has yet to be demonstrated experimentally. Here, we report the construction of a wildtype cDNA clone, pGPGV-SY, based on ON93-12, a local isolate from Syrah closely related to the variants encoding the larger MP. Surprisingly, our clone exhibited significantly faster replication and caused more severe disease symptoms than pRI::GPGV-lat, an Italian GPGV clone, with a longer MP and demonstrated similar efficacies with that of pRI::GPGV-vir, another Italian clone with a shorter MP. A single C to T mutation at the polymorphic site of pGPGV-SY resulted in a two-fold higher RNA accumulation in the grapevine. Findings from this work constitute a leap toward the long-standing and complex question pertaining to the relationship between GPGV variant groups and GLMD. Integrating findings from this work and those by others, we propose an updated model to explain the complex relationship between GPGV variants and GLMD
Valutazione della fitotossicità di nuove formulazioni di rame chelato ad amminoiacidi e peptici e studio ultrastrutturale delle alterazioni fogliari prodotte
No full textSieve-element biology provides leads for research on phytoplasma lifestyle in plant hosts
No full textPhytoplasmas reside exclusively in sieve tubes, tubular arrays of sieve element-companion cell complexes. Hence, the cell biology of sieve elements may reveal (ultra)structural and functional conditions that may be of significance for survival, propagation, colonization and effector spread of phytoplasmas. Electron-microscopic pictures suggest that sieve elements offer facilities for mobile and stationary stages in phytoplasma movement. Stationary stages may enable phytoplasmas to closely interact with diverse sieve-element compartments. The unique, reduced sieve-element outfit requires permanent support by companion cells. This notion implies a future focus on the molecular biology of companion cells to understand the sieve-element/phytoplasma interrelationship. Supply of macromolecules by companion cells is channelled via specialized symplasmic connections. Ca2+-mediated gating of symplasmic corridors is decisive for the communication within and beyond the sieve element-companion cell complex and for the dissemination of phytoplasma effectors. Thus, Ca2+ homeostasis, which affects sieve-element Ca2+ signatures and induces a range of modifications, is a key issue during phytoplasma infection. The exceptional physical and chemical environment in sieve elements seems an essential, though not the only factor for phytoplasma survival
Detection and characterization of phytoplasmas infecting sesame and solanaceous crops in Turkey
No full text
Trigger and suppression of antiviral defenses by grapevine Pinot gris virus (GPGV): novel insights into virus-host interaction.
Full text linkGrapevine Pinot gris virus (GPGV) is an emerging trichovirus that has been putatively associatedwith a novel grapevine disease known as grapevine leaf mottling and deformation (GLMD). Yet the role ofGPGV inGLMD disease is poorly understood, since it has been detected both in symptomatic and symptomless grapevines. Weexploited a recently constructed GPGV infectious clone (pRI::GPGV-vir) to induce an antiviral response in Nicotiana benthamiana plants. In silico prediction of virus-derived small interfering RNAs and gene expression analyses revealed the involvement of DCL4, AGO5, and RDR6 genes during GPGV infection, suggesting the activation of the posttranscriptional gene-silencing (PTGS) pathway as a plant antiviral defense. PTGS suppression assays in transgenic N. benthamiana 16c plants revealed the ability of the GPGV coat protein to suppress RNA silencing. This work provides novel insights on the interaction betweenGPGV and its host, revealing the ability of the virus to trigger and suppress antiviral RNA silencing
- …
