676 research outputs found
Cold treatment breaks dormancy but jeopardizes flower quality in Camellia japonica L.
Camellia japonica L. is an evergreen shrub whose cultivars are of great ornamental value. In autumn, after flower bud differentiation, dormancy is initiated. As in many other spring flowering woody ornamentals, winter low temperatures promote dormancy release of both flower and vegetative buds. However, warm spells during late autumn and winter can lead to unfulfilled chilling requirements leading to erratic and delayed flowering. We hypothesized that storing plants at no light and low temperature could favor dormancy breaking and lead to early and synchronized flowering in response to forcing conditions in C. japonica ‘Nuccio’s Pearl’. Plants with fully developed floral primordia were stored at dark, 7∘C, and RH > 90% for up to 8 weeks. To monitor endodormancy release during the storage, we evaluated the content of abscisic acid (ABA) in flower buds and the expression profiles of five putative genes related to dormancy and cold acclimation metabolism in leaves and flower buds. In addition, the expression of four anthocyanin biosynthesis pathway genes was profiled in flower buds to assess the effect of the treatment on flower pigment biosynthesis. At 0, 4, 6, and 8 weeks of cold treatment, 10 plants were transferred to the greenhouse and forced to flower. Forced plant flower qualities and growth were observed. The ABA content and the expression profiles of two dormancy-related genes (CjARP and CjDEH) suggested that dormancy breaking occurred after 6–8 weeks of cold treatment. Overall, plants treated for 6–8 weeks showed earlier vegetative sprouting, enhanced, and homogeneous flowering with reduced forcing time. Prolonged cold treatments also reduced flower size and longevity, anthocyanin content, and pigment biosynthesis-related gene transcripts. In conclusion, the cold treatment had a promotive effect on dormancy breaking but caused severe drawbacks on flower quality
Wild Camellia japonica specimens in the Shimane prefecture (Japan) host previously undescribed AMF diversity
Application of laser microdissection to identify the mycorrhizal fungi that establish arbuscules inside root cells.
Obligate symbiotic fungi that form arbuscular mycorrhizae (AMF; belonging to the Glomeromycota phylum) are some of the most important soil microorganisms. AMFs facilitate mineral nutrient uptake from the soil, in exchange for plant-assimilated carbon, and promote water-stress tolerance and resistance to certain diseases. AMFs colonize the root by producing inter- and intra-cellular hyphae. When the fungus penetrates the inner cortical cells, it produces a complex ramified structure called arbuscule, which is considered the preferential site for nutrient exchange. Direct DNA extraction from the whole root and sequencing of ribosomal gene regions are commonly carried out to investigate intraradical AMF communities. Nevertheless, this protocol cannot discriminate between the AMFs that actively produce arbuscules and those that do not. To solve this issue, the authors have characterized the AMF community of arbusculated cells (AC) through a laser microdissection (LMD) approach, combined with sequencing-based taxa identification. The results were then compared with the AMF community that was found from whole root DNA extraction. The AMF communities originating from the LMD samples and the whole root samples differed remarkably. Five taxa were involved in the production of arbuscules, while two taxa were retrieved inside the root but not in the AC. Unexpectedly, one taxon was found in the AC, but its detection was not possible when extracting from the whole root. Thus, the LMD technique can be considered a powerful tool to obtain more precise knowledge on the symbiotically active intraradical AMF community
Arbuscular Mycorrhizal Fungi and their Value for Ecosystem Management
Arbuscular Mycorrhizal Fungi (AMF) are root obligate symbionts of nearly all the plants living on Earth. They are considered as living fossils: there are evidences that date back to 460 million years ago their presence on our planet. Taxonomically, they belong to the Glomeromycota phylum. They are found in roots of 80% of plant species and give and get back benefits to their partners, as happens in all mutual symbiotic relationships. They build up a bridge between plant and soil, growing their mycelia both inside and outside plant roots. AMF provide the plant with water, soil mineral nutrients (mainly phosphorus and nitrogen), and pathogen protection. In exchange, photosynthetic compounds are transferred to the fungus.
Besides physiological benefits to the host-plant, AMF play an important ecological role. They are important in soil structuring thanks to their thick extraradical hyphal network able to aggregate soil particles. They help plants establish in degraded ecosystems (e.g. desert areas and mine spoils) and positively affect phytoremediation. They can influence processes (i.e. soil carbon sequestration) related to climate change. Last but not least, their belowground presence and diversity can positively affect the aboveground plant biodiversity and productivity.
These roles played by AMF for the ecosystem functioning lead to consider them as key soil organisms. Therefore, every AMF aspect is extensively studied: from biological features, through biogeography and biodiversity, to phylogeny. [...]JRC.H.5-Land Resources Managemen
The Evolving Treatment Landscape of Medullary Thyroid Cancer
Genetic assessment is crucial to address the correct treatment for advanced medullary thyroid cancer (MTC). Multi tyrosine kinase inhibitors (mTKIs) cabozantinib and vandetanib are good first line options, even vandetanib prescription is currently limited to RET mutated patients. Selective RET inhibitors such as pralsetinib could be a preferred upfront treatment in case of RET mutated MTC presenting common or gatekeeper RET mutations (e.g. M918T; V804L/M). Selpercatinib, otherwise, can be prescribed as the second line after disease progression to mTKIs. The best option for subsequent lines is to consider inclusion in clinical trials or alternatively other mTKIs such as sunitinib, sorafenib, lenvatinib, or pazopanib could be evaluated. New perspectives include next-generation RET inhibitors able to overcome resistance mechanisms responsible for disease progression to standard mTKIs and RET inhibitors, and immunotherapy for MTC presenting with high tumor mutational burden
Saffron Cultivation in Marginal Alpine Environments: How AMF Inoculation Modulates Yield and Bioactive Compounds
Malignant pleural mesothelioma: clinicopathologic and survival characteristics in a consecutive series of 394 patients☆
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