Search results for " protein"
showing 10 items of 12147 documents
Chlorophyll fluorescence emission spectrum inside a leaf
2008
International audience; Chlorophyll a fluorescence can be used as an early stress indicator. Fluorescence is also connected to photosynthesis so it can be proposed for global monitoring of vegetation status from a satellite platform. Nevertheless, the correct interpretation of fluorescence requires accurate physical models. The spectral shape of the leaf fluorescence free of any re-absorption effect plays a key role in the models and is difficult to measure. We present a vegetation fluorescence emission spectrum free of re-absorption based on a combination of measurements and modelling. The suggested spectrum takes into account the photosystem I and II spectra and their relative contributio…
Iron acquisition from Fe-pyoverdine by Arabidopsis thaliana.
2007
Taking into account the strong iron competition in the rhizosphere and the high affinity of pyoverdines for Fe(III), these molecules are expected to interfere with the iron nutrition of plants, as they do with rhizospheric microbes. The impact of Fe-pyoverdine on iron content of Arabidopsis thaliana was compared with that of Fe-EDTA. Iron chelated to pyoverdine was incorporated in a more efficient way than when chelated to EDTA, leading to increased plant growth of the wild type. A transgenic line of A. thaliana overexpressing ferritin showed a higher iron content than the wild type when supplemented with Fe-EDTA but a lower iron content when supplemented with Fe-pyoverdine despite its inc…
Ions channels/transporters and chloroplast regulation.
2015
International audience; Ions play fundamental roles in all living cells and their gradients are often essential to fuel transports, to regulate enzyme activities and to transduce energy within and between cells. Their homeostasis is therefore an essential component of the cell metabolism. Ions must be imported from the extracellular matrix to their final subcellular compartments. Among them, the chloroplast is a particularly interesting example because there, ions not only modulate enzyme activities, but also mediate ATP synthesis and actively participate in the building of the photosynthetic structures by promoting membrane-membrane interaction. In this review, we first provide a comprehen…
Development of an UHPLC-Q-Orbitrap HRMS method for simultaneous determination of mycotoxins and isoflavones in soy-based burgers
2019
Abstract Soy-based burgers, an option of meatless hamburger-style, are basically made with soy protein, wholegrains and veggies. However, some ingredients, such as cereals and soybean, are particularly susceptible to fungal contamination. Therefore, a fast and simple procedure for the simultaneous determination of isoflavones (n=12) and mycotoxins (n=21) in soy-based burgers was developed throughout an acetonitrile-based extraction and UHPLC-Q-Exactive Orbitrap HRMS determination for the first time. The procedure was properly validated in terms of linearity, accuracy (recovery range from 78 to 108%) and precision (RSD
Arginase induction represses gall development during clubroot infection in Arabidopsis.
2012
Arginase induction can play a defensive role through the reduction of arginine availability for phytophageous insects. Arginase activity is also induced during gall growth caused by Plasmodiophora brassicae infection in roots of Arabidopsis thaliana; however, its possible role in this context has been unclear. We report here that the mutation of the arginase-encoding gene ARGAH2 abrogates clubroot-induced arginase activity and results in enhanced gall size in infected roots, suggesting that arginase plays a defensive role. Induction of arginase activity in infected roots was impaired in the jar1 mutant, highlighting a link between the arginase response to clubroot and jasmonate signaling. C…
The genome sequencing of an albino Western lowland gorilla reveals inbreeding in the wild
2013
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License.-- et al.
Binding Site Alteration Is Responsible for Field-Isolated Resistance to Bacillus thuringiensis Cry2A Insecticidal Proteins in Two Helicoverpa Species
2010
Background Evolution of resistance by target pests is the main threat to the long-term efficacy of crops expressing Bacillus thuringiensis (Bt) insecticidal proteins. Cry2 proteins play a pivotal role in current Bt spray formulations and transgenic crops and they complement Cry1A proteins because of their different mode of action. Their presence is critical in the control of those lepidopteran species, such as Helicoverpa spp., which are not highly susceptible to Cry1A proteins. In Australia, a transgenic variety of cotton expressing Cry1Ac and Cry2Ab (Bollgard II) comprises at least 80% of the total cotton area. Prior to the widespread adoption of Bollgard II, the frequency of alleles conf…
Insecticidal Activity of Bacillus thuringiensis Proteins against Coleopteran Pests
2020
Bacillus thuringiensis is the most successful microbial insecticide agent and its proteins have been studied for many years due to its toxicity against insects mainly belonging to the orders Lepidoptera, Diptera and Coleoptera, which are pests of agro-forestry and medical-veterinary interest. However, studies on the interactions between this bacterium and the insect species classified in the order Coleoptera are more limited when compared to other insect orders. To date, 45 Cry proteins, 2 Cyt proteins, 11 Vip proteins, and 2 Sip proteins have been reported with activity against coleopteran species. A number of these proteins have been successfully used in some insecticidal formulations and…
AtCCS is a functional homolog of the yeast copper chaperone Ccs1/Lys7
2005
AbstractIn plant chloroplasts two superoxide dismutase (SOD) activities occur, FeSOD and Cu/ZnSOD, with reciprocal regulation in response to copper availability. This system presents a unique model to study the regulation of metal-cofactor delivery to an organelle. The Arabidopsis thaliana gene AtCCS encodes a functional homolog to yeast Ccs1p/Lys7p, a copper chaperone for SOD. The AtCCS protein was localized to chloroplasts where it may supply copper to the stromal Cu/ZnSOD. AtCCS mRNA expression levels are upregulated in response to Cu-feeding and senescence. We propose that AtCCS expression is regulated to allow the most optimal use of Cu for photosynthesis.
Constitutive Activation of the Midgut Response to Bacillus thuringiensis in Bt-Resistant Spodoptera exigua
2010
Bacillus thuringiensis is the most effective microbial control agent for controlling numerous species from different insect orders. The main threat for the long term use of B. thuringiensis in pest control is the ability of insects to develop resistance. Thus, the identification of insect genes involved in conferring resistance is of paramount importance. A colony of Spodoptera exigua (Lepidoptera: Noctuidae) was selected for 15 years in the laboratory for resistance to Xentari (TM), a B. thuringiensis-based insecticide, reaching a final resistance level of greater than 1,000-fold. Around 600 midgut ESTs were analyzed by DNA-macroarray in order to find differences in midgut gene expression …