Search results for "QD"
showing 10 items of 2226 documents
An Arabidopsis Mutant Over-Expressing Subtilase SBT4.13 Uncovers the Role of Oxidative Stress in the Inhibition of Growth by Intracellular Acidificat…
2020
Intracellular acid stress inhibits plant growth by unknown mechanisms and it occurs in acidic soils and as consequence of other stresses. In order to identify mechanisms of acid toxicity, we screened activation-tagging lines of Arabidopsis thaliana for tolerance to intracellular acidification induced by organic acids. A dominant mutant, sbt4.13-1D, was isolated twice and shown to over-express subtilase SBT4.13, a protease secreted into endoplasmic reticulum. Activity measurements and immuno-detection indicate that the mutant contains less plasma membrane H+-ATPase (PMA) than wild type, explaining the small size, electrical depolarization and decreased cytosolic pH of the mutant but not orga…
Synthesis of Isomaltooligosaccharides by Saccharomyces cerevisiae Cells Expressing Aspergillus niger α‑Glucosidase
2017
The α-glucosidase encoded by the aglA gene of Aspergillus niger is a secreted enzyme belonging to family 31 of glycoside hydrolases. This enzyme has a retaining mechanism of action and displays transglycosylating activity that makes it amenable to be used for the synthesis of isomaltooligosaccharides (IMOs). We have expressed the aglA gene in Saccharomyces cerevisiae under control of a galactose-inducible promoter. Recombinant yeast cells expressing the aglA gene produced extracellular α-glucosidase activity about half of which appeared cell bound whereas the other half was released into the culture medium. With maltose as the substrate, panose is the main transglycosylation product after 8…
Symptom severity, infection progression and plant responses in solanum plants caused by three pospiviroids vary with the inoculation procedure
2021
This article belongs to the Section Molecular Plant Sciences.
Anthocyanins of Coloured Wheat Genotypes in Specific Response to SalStress
2018
The present study investigated the effect of salt stress on the development of adaptive responses and growth parameters of different coloured wheat genotypes. The different coloured wheat genotypes have revealed variation in the anthocyanin content, which may affect the development of adaptive responses under increasing salinity stress. In the early stage of treatment with salt at a lower NaCl concentration (100 mM), anthocyanins and proline accumulate, which shows rapid development of the stress reaction. A dose-dependent increase in flavonol content was observed for wheat genotypes with more intense purple-blue pigmentation after treatment with 150 mM and 200 mM NaCl. The content of Na⁺ a…
Does silica concentration and phytolith ultrastructure relate to phytolith hardness?
2017
Abstract Grasses are an important part of the forage of many herbivorous mammals and their phytoliths have long been regarded as the most important agent of tooth wear. Recent work has challenged this “paradigm” in finding evidence 1. of native phytoliths to be much softer then tooth enamel and 2. indicating, that phytolith hardness is highly variable, 3. prone to methodology and 4. not easy to be related to habitat conditions. We conduct controlled silica-cultivations measuring SiO2 content in the common forage grass Themeda triandra. Phytoliths are extracted natively, and nano-indentation values are measured. Phytolith hardness in Themeda triandra is found to be independent of silicate av…
Genome-Wide Profiling and Phylogenetic Analysis of the SWEET Sugar Transporter Gene Family in Walnut and Their Lack of Responsiveness to Xanthomonas …
2020
Following photosynthesis, sucrose is translocated to sink organs, where it provides the primary source of carbon and energy to sustain plant growth and development. Sugar transporters from the SWEET (sugar will eventually be exported transporter) family are rate-limiting factors that mediate sucrose transport across concentration gradients, sustain yields, and participate in reproductive development, plant senescence, stress responses, as well as support plant&ndash
Control of Erigeron bonariensis with Thymbra capitata, Mentha piperita, Eucalyptus camaldulensis, and Santolina chamaecyparissus Essential Oils
2020
In the search of sustainable and environmentally friendly methods for weed control, there is increasing interest in essential oils (EOs) as an approach to reduce synthetic herbicide use. The phytotoxicity of Thymbra capitata, Mentha piperita, Eucalyptus camaldulensis, and Santolina chamaecyparissus EOs against the noxious weed Erigeron bonariensis were evaluated in pre- and post-emergence assays in greenhouse conditions. The EOs were applied at 2, 4, and 8 µ
Iodine emissions from the sea ice of the Weddell Sea
2012
Iodine compounds were measured above, below and within the sea ice of the Weddell Sea during a cruise in 2009, to make progress in elucidating the mechanism of local enhancement and volatilisation of iodine. I<sub>2</sub> mixing ratios of up to 12.4 pptv were measured 10 m above the sea ice, and up to 31 pptv was observed above surface snow on the nearby Brunt Ice Shelf – large amounts. Atmospheric IO of up to 7 pptv was measured from the ship, and the average sum of HOI and ICl was 1.9 pptv. These measurements confirm the Weddell Sea as an iodine hotspot. Average atmospheric concentrations of CH<sub>3</sub>I, C<sub>2</sub>H<sub>5</sub>I, CH&l…
Land cover and its transformation in the backward trajectory footprint region of the Amazon Tall Tower Observatory
2019
Abstract. The Amazon rain forest experiences the combined pressures from human-made deforestation and progressing climate change, causing severe and potentially disruptive perturbations of the ecosystem's integrity and stability. To intensify research on critical aspects of Amazonian biosphere–atmosphere exchange, the Amazon Tall Tower Observatory (ATTO) has been established in the central Amazon Basin. Here we present a multi-year analysis of backward trajectories to derive an effective footprint region of the observatory, which spans large parts of the particularly vulnerable eastern basin. Further, we characterize geospatial properties of the footprint regions, such as climatic condition…
Herbicidal activity of Thymbra capitata (L.) Cav. essential oil
2020
The bioherbicidal potential of Thymbra capitata (l.) Cav. essential oil (EO) and its main compound carvacrol was investigated. In in vitro assays, the EO blocked the germination and seedling growth of Erigeron canadensis L., Sonchus oleraceus (l.) L., and Chenopodium album L. at 0.125 µ