Search results for "HT"
showing 10 items of 20594 documents
Regulation of endocytosis by external stimuli in plant cells
2009
International audience; Endocytosis is an essential process for the normal growth and development of eukaryotic cells. This mini-review presents an overview of endocytosis regulation in challenging environmental conditions such as nutrient availability, hormonal treatment or abiotic/biotic stress in plant cells. Recent data establishing a relationship between endocytosis and reactive oxygen species (ROS) production are also discussed.
Raspberry breeding and biotisation for increasing plant stress tolerance and antioxidant activity
2008
International audience; Chemical inputs used in red fruit production can be detrimental to the environment and pesticides are not always efficient in controlling plant diseases. In addition, it is suspected that conventional agricultural practices have a negative impact on antioxidant activities in red fruits. Therefore new cultural approaches are required in order to produce red fruits of high quality. This involves an integrated programme of plant breeding and development of sustainable agricultural practices. Antioxidant activity was compared in leaves and berries of six raspberry cultivars for the selection of varieties for a breeding programme. This showed that cultivars that had the h…
Fruit size in relation to competition for resources: A common model shared by two species and several genotypes grown under contrasted carbohydrate l…
2012
International audience; Fruit size is one important criterion of fruit external quality affecting consumer acceptance. The effects of seed number on fruit size in two fleshy fruits, grape and tomato, of different genotypes and grown under distinct carbohydrate availability levels were analyzed with a model. The two-parameter model described within-fruit resource competition and was able to well represent the commonly observed decrease in fresh weight per seed along with the increase in number of seeds, regardless of species, genotypes, and carbohydrate levels that were evaluated in this study. However, carbohydrate levels largely modified the correlation between seed number and fresh weight…
Pseudomonas salomonii sp. nov., pathogenic on garlic, and Pseudomonas palleroniara sp. nov., isolated from rice
2002
International audience; A total of 26 strains, including 15 strains isolated from garlic plants with the typical symptoms of 'Café au lait' disease and 11 strains isolated from diseased or healthy rice seeds and sheaths infested by Pseudomonas fuscovaginae, were compared with 70 type or reference strains of oxidase-positive pathogenic or non-pathogenic fluorescent pseudomonads. The strains were characterized by using a polyphasic taxonomic approach. Numerical taxonomy of phenotypic characteristics showed that the garlic and rice strains were related to each other. However, they clustered into separate phenons, distinct from those of the other strains tested, and were different in several nu…
Physiological and Structural Changes in Tobacco Leaves Treated with Cryptogein, a Proteinaceous Elicitor fromPhytophthora cryptogea
1991
Cryptogein was applied on the petiole section of excised tobacco leaves. It elicited necroses that can be correlated with histological alterations, such as rapid chloroplast breakdown and a collapse of cells leading to disorganization of the parenchyma tissue. In addition, it induced ethylene production and accumulation of capsidiol. In order to detect an early response, we analyzed the kinetics of chlorophyll fluorescence induction (...)
Solute transporters in plant thylakoid membranes
2010
International audience; Plants utilize sunlight to drive photosynthetic energy conversion in the chloroplast thylakoid membrane. Here are located four major photosynthetic complexes, about which we have great knowledge in terms of structure and function. However, much less we know about auxiliary proteins, such as transporters, ensuring an optimum function and turnover of these complexes. The most prominent thylakoid transporter is the proton-translocating ATP-synthase. Recently, four additional transporters have been identified in the thylakoid membrane of Arabidopsis thaliana, namely one copper-transporting P-ATPase, one chloride channel, one phosphate transporter, and one ATP/ADP carrier…
Pea Efficiency of Post-drought Recovery Relies on the Strategy to Fine-Tune Nitrogen Nutrition
2020
International audience; As drought is increasingly frequent in the context of climate change it is a major constraint for crop growth and yield. The ability of plants to maintain their yield in response to drought depends not only on their ability to tolerate drought, but also on their capacity to subsequently recover. Post-stress recovery can indeed be decisive for drought resilience and yield stability. Pea (Pisum sativum), as a legume, has the capacity to fix atmospheric nitrogen through its symbiotic interaction with soil bacteria within root nodules. Biological nitrogen fixation is highly sensitive to drought which can impact plant nitrogen nutrition and growth. Our study aimed at dyna…
Trophic upgrading via the microbial food web may link terrestrial dissolved organic matter to Daphnia
2017
Direct consumption of allochthonous resources generally yields poor growth and reproduction in zooplankton, but it is still unclear how trophic upgrading of terrestrial dissolved organic matter (tDOM) via the microbial food web may support zooplankton. We compared survival, somatic growth and reproduction of Daphnia magna fed with the heterotrophic flagellate Paraphysomonas vestita and three algal diets. Paraphysomonas was fed lake bacteria that used tDOM as a substrate to simulate an allochthonous diet that zooplankton encounter in lakes. The highest survival, growth and reproduction was achieved with a diet of Cryptomonas, while Daphnia performance was the worst when fed Microcystis. Para…
Assortative pairing for boldness and consequences for reproductive success in Montagu’s harrier
2021
Abstract Behavioural combination within pairs depending on personality and plasticity might influence reproductive success. However, studies testing this hypothesis are rare, especially in the case of monogamous species with bi-parental care in which the sexes exhibit different behavioural roles. In this study, we investigated the pairing patterns for both boldness and boldness plasticity in Montagu’s harriers (Circus pygargus), a species with sex-specific care, and the consequences for their reproductive success. We measured individual boldness and plasticity for both sexes, and we assessed the pairing pattern in the Montagu’s harrier population for these two traits. We calculated four ind…
Habitat quality is more important than matrix quality for bird communities in protected areas
2018
Protected areas are meant to preserve native local communities within their boundaries, but they are not independent from their surroundings. Impoverished habitat quality in the matrix might influence the species composition within the protected areas through biotic homogenization. The aim of this study was to determine the impacts of matrix quality on species richness and trait composition of bird communities from the Finnish reserve area network and whether the communities are being subject of biotic homogenization due to the lowered quality of the landscape matrix. We used joint species distribution modeling to study how characteristics of the Finnish forest reserves and the quality of t…