Search results for "ABIOTIC"
showing 10 items of 201 documents
Post-Translational Modifications of Nuclear Proteins in the Response of Plant Cells to Abiotic Stresses
2011
For a long time, in plant cells as in animal cells, the nucleus was only considered as the organelle in which fundamental mechanisms such as replication and transcription occurred. While strong efforts were deployed in order to identify important families of transcription factors such as MYB, WRKY or TGA families (Dubos et al., 2010; Rushton et al., 2010), a few attention was devoted to our lack of knowledge about their regulation in regard to the physiological conditions of the plant cells. Whereas the major importance of posttranslational modification of proteins is well established for several decades regarding cytosolic proteins, the last years have been characterized by the discovery t…
Factors Affecting Polyphenol Biosynthesis in Wild and Field Grown St. John’s Wort (Hypericum perforatum L. Hypericaceae/Guttiferae)
2009
The increasing diffusion of herbal products is posing new questions: why are products so often different in their composition and efficacy? Which approach is more suitable to increase the biochemical productivity of medicinal plants with large-scale, low-cost solutions? Can the phytochemical profile of a medicinal plant be modulated in order to increase the accumulation of its most valuable constituents? Will polyphenol-rich medicinal crops ever be traded as commodities? Providing a proactive answer to such questions is an extremely hard task, due to the large number of variables involved: intraspecific chemodiversity, plant breeding, ontogenetic stage, post-harvest handling, biotic and abi…
Macrolepidoptera (Insecta: Lepidoptera) Indicator of Climate Changes
2011
Lately, it has become increasingly clear that global warming has a significant impact on a broad range of organisms, regardless of their ecological and geographical spread. Temperature is one of the most important abiotic factors that determine the spatiotemporal dynamics of structural and functional parameters of populations of Lepidoptera and influencing production and survival of these species of insects in nature. Climate warming has the potential to affect some processes related to the ecology and life cycle of the butterfly, especially directly controlled temperature, such as: gathering the required temperature for a species to reach reproductive maturity, growth initiation and cessat…
Interfacial photochemistry of biogenic surfactants: a major source of abiotic volatile organic compounds
2017
Films of biogenic compounds exposed to the atmosphere are ubiquitously found on the surfaces of cloud droplets, aerosol particles, buildings, plants, soils and the ocean. These air/water interfaces host countless amphiphilic compounds concentrated there with respect to in bulk water, leading to a unique chemical environment. Here, photochemical processes at the air/water interface of biofilm-containing solutions were studied, demonstrating abiotic VOC production from authentic biogenic surfactants under ambient conditions. Using a combination of online-APCI-HRMS and PTR-ToF-MS, unsaturated and functionalized VOCs were identified and quantified, giving emission fluxes comparable to previous …
Environmental stress affects the expression of a carotenoid-based sexual trait in male zebra finches.
2007
SUMMARY Abiotic factors including thermal stress are suggested to exert constrains on sexual ornaments through trade-offs between sexual displays and physiological functions related to self-maintenance. Given the health properties of carotenoid pigments, carotenoid-based ornaments offer a relevant context in which to investigate the effect of environmental stress, such as ambient temperature, on the production and maintenance of secondary sexual traits and, also, to explore the proximate mechanisms shaping their expression. In this study, we exposed male zebra finches (Taeniopygia guttata) to environmental stress by exposing them to two temperature regimes (6 and 26°C) over a 4 week period.…
Parasites as Indicators of Water Quality and the Potential Use of Helminth Transmission in Marine Pollution Studies
1995
Publisher Summary This chapter focuses on parasites as indicators of water quality and the potential use of helminth transmission in marine pollution studies. There are good reasons for focusing on parasitic organisms in general and helminth parasites in particular, in the search for highly sensitive indicators. First, there are more parasitic than free-living species. Second, helminth parasites have complex life cycles and the different developmental stages have widely differing requirements, therefore, each stage must be assessed separately for sensitivity to environmental change, thereby widening the choice of potential indicators. Many biotic and abiotic factors affect the numbers and d…
Metacommunities from bacteria to birds: stronger environmental selection in mediterranean than in tropical ponds
2021
AbstractThe metacommunity concept provides a theoretical framework that aims at explaining organism distributions by a combination of environmental filtering, dispersal and drift. With the development of statistical tools to quantify and partially isolate the role of each of these processes, empirical metacommunity studies have multiplied worldwide. However, few works attempt a multi-taxon approach and even fewer compare two distant biogeographical regions using the same methodology. Under this framework, we tested the expectation that temperate (mediterranean-climate) pond metacommunities would be more influenced by environmental and spatial processes than tropical ones, because of stronge…
Evaluating anthropogenic impacts on naturally stressed ecosystems: Revisiting river classifications and biomonitoring metrics along salinity gradients
2019
Naturally stressed ecosystems hold a unique fraction of biodiversity. However, they have been largely ignored in biomonitoring and conservation programmes, such as the EU Water Framework Directive, while global change pressures are threatening their singular values. Here we present a framework to classify and evaluate the ecological quality of naturally stressed rivers along a water salinity gradient. We gathered datasets, including aquatic macroinvertebrate assemblages and environmental information, for 243 river locations across the western Mediterranean to: a) gauge the role of natural stressors (salinity) in driving aquatic community richness and composition; b) make river classificatio…
Combined Stress Conditions in Melon Induce Non-additive Effects in the Core miRNA Regulatory Network
2021
Climate change has been associated with a higher incidence of combined adverse environmental conditions that can promote a significant decrease in crop productivity. However, knowledge on how a combination of stresses might affect plant development is still scarce. MicroRNAs (miRNAs) have been proposed as potential targets for improving crop productivity. Here, we have combined deep-sequencing, computational characterization of responsive miRNAs and validation of their regulatory role in a comprehensive analysis of response of melon to several combinations of four stresses (cold, salinity, short day, and infection with a fungus). Twenty-two miRNA families responding to double and/or triple …
Starvation can diversify the population structure and virulence strategies of an environmentally transmitting fish pathogen.
2013
Background Generalist bacterial pathogens, with the ability for environmental survival and growth, often face variable conditions during their outside-host period. Abiotic factors (such as nutrient deprivation) act as selection pressures for bacterial characteristics, but their effect on virulence is not entirely understood. “Sit and wait” hypothesis expects that long outside-host survival selects for increased virulence, but maintaining virulence in the absence of hosts is generally expected to be costly if active investments are needed. We analysed how long term starvation influences bacterial population structure and virulence of an environmentally transmitting fish pathogen Flavobacteri…