Literatura científica selecionada sobre o tema "Comparative eco-Physiology"

Increasing discharge and improper management of liquid and solid industrial wastes have created a great concern among industrialists and the scientific community over their economic treatment and safe disposal. Hence, there is a growing need for the development of novel, efficient, eco-friendly, and cost-effective approach for the remediation for these industries released into the environment and to safeguard the ecosystem. In this regard, recent advances in wastewater of heavy metal have propelled bioremediation as a prospective alternative to conventional techniques. Heavy metals are toxic and dangerous to the ecosystem. White rot fungi (WRF) are versatile and robust organisms having enormous potential for oxidative bioremediation of a variety of toxic chemical pollutants due to high tolerance to toxic substances in the environment. The decolorization and detoxification potential of WRF can be harnessed thanks to emerging knowledge of the physiology of these organisms as well as of the bio catalysis and stability characteristics of their enzymes. This knowledge will need to be transformed into reliable and robust waste treatment processes.

To date, the overwhelming majority of genomics programs in plants have been directed at model or crop plant species, meaning that very little of the naturally occurring sequence diversity found in plants is available for characterization and exploitation. In contrast, ‘xenogenomics’ refers to the discovery and functional analysis of novel genes and alleles from indigenous and exotic species, permitting bioprospecting of biodiversity using high-throughput genomics experimental approaches. Such a program has been initiated to bioprospect for genetic determinants of abiotic stress tolerance in indigenous Australian flora and native Antarctic plants. Uniquely adapted Poaceae and Fabaceae species with enhanced tolerance to salt, drought, elevated soil aluminium concentration, and freezing stress have been identified, based primarily on their eco-physiology, and have been subjected to structural and functional genomics analyses. For each species, EST collections have been derived from plants subjected to appropriate abiotic stresses. Transcript profiling with spotted unigene cDNA micro-arrays has been used to identify genes that are transcriptionally modulated in response to abiotic stress. Candidate genes identified on the basis of sequence annotation or transcript profiling have been assayedin plantaand otherin vivosystems for their capacity to confer novel phenotypes. Comparative genomics analysis of novel genes and alleles identified in the xenogenomics target plant species has subsequently been undertaken with reference to key model and crop plants.

The intake of hesperidin-rich sources, mostly found in orange juice, can decrease cardiometabolic risk, potentially linked to the gut microbial phase-II hesperetin derivatives. However, the low hesperidin solubility hampers its bioavailability and microbial metabolism, yielding a high inter-individual variability (high vs. low-producers) that prevents consistent health-related evidence. Contrarily, the human metabolism of (lemon) eriocitrin is hardly known. We hypothesize that the higher solubility of (lemon) eriocitrin vs. (orange) hesperidin might yield more bioavailable metabolites than hesperidin. A randomized-crossover human pharmacokinetic study (n = 16) compared the bioavailability and metabolism of flavanones from lemon and orange extracts and postprandial changes in oxidative, inflammatory, and metabolic markers after a high-fat-high-sugars meal. A total of 17 phase-II flavanone-derived metabolites were identified. No significant biomarker changes were observed. Plasma and urinary concentrations of all metabolites, including hesperetin metabolites, were higher after lemon extract intake. Total plasma metabolites showed significantly mean lower Tmax (6.0 ± 0.4 vs. 8.0 ± 0.5 h) and higher Cmax and AUC values after lemon extract intake. We provide new insights on hesperetin-eriodictyol interconversion and naringenin formation from hesperidin in humans. Our results suggest that regular consumption of a soluble and eco-friendly eriocitrin-rich lemon extract could provide a circulating concentration metabolites threshold to exert health benefits, even in the so-called low-producers.

The nature of pollen grains and karyotype morphology are important bases in the task of clarifying relationships and they are considered to be of significant value in observing the effects of environmental and climatic factors on plants. The investigations of the palynological, as well as karyological and physiological data regarding to M. coralloides, as one of the rarest species of the Armenian flora, were conducted for the first time using light and scanning electronic microscopy. In Armenia the only remaining population of this species is currently located in the Ararat valley salt marshes to the south-east of Ararat town. In the Red Book of Plants of the Republic of Armenia the species M. coralloides is presented in the category EN (Endangered species). Description of the pollen grain and karyotype of the Armenian population of M. coralloides subsp. anatolicum collected from the vicinity of Ararat town are provided in the article. The study of the water regime, transpiration intensity and photosynthesis, as well as plastid pigments were also conducted. Comparative analysis between Armenian and Iranian specimens of the subspecies M. coralloides subsp. anatolicum showed some discrepancies in pollen features, as well as karyological data, which indicate some specificity of the population growing on the territory of Armenia. The diversity and intersections in pollen traits can be attributed to either natural variability within a population (plasticity), or they may be influenced by genetic differences among populations and closely related species. The physiological data highlights specialized adaptations of M. coralloides subsp. anatolicum for managing water resources, reducing transpiration, and performing photosynthesis in the high salinity conditions of the Ararat Plain. This showcases the plant's remarkable resilience and adaptability to its specific ecological niche, emphasizing the interplay between environment and biology.

The ultrasonic-assisted aqueous two-phase extraction (UAATPE) of flavonoid glycosides from Malvaviscus arboreous Cav. flower (MACF) was developed using ethanol/ammonia sulfate systems, followed by the ultrasonic-assisted acid hydrolysis (UAAH) of the top extract with HCl solution. The optimization of UAATPE and UAAH processes was accomplished by single-factor experiments and response surface methodology. As a result, the flavonoid glycosides enriched in the top phase could achieve a maximum yield of 35.9 ± 1.1 mg/g by UAATPE and were completely hydrolyzed by UAAH deglycosylation. The flavonoid glycosides and their hydrolyzates were separated and characterized by high-performance liquid chromatography and ultra-high-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry. Ultrasonic enhancement of the extraction and hydrolysis was explored by comparative study. Furthermore, the in vitro activity of the flavonoid glycosides and the aglycones were comprehensively evaluated by antioxidant activity assays, including ferric-reducing antioxidant power and scavenging DPPH, hydroxyl, and superoxide radicals. All of the IC50 values suggest that the antioxidant activity of flavonoid aglycones was stronger than that of their glucosides and even vitamin C, revealing that the deglycosylated flavonoids from MACF were the more powerful antioxidants. This study provided an effective and eco-friendly strategy for the extraction, separation, and purification of flavonoids from MACF, as well as for the development of the potential flavonoid antioxidants.

ECR Spotlight is a series of interviews with early-career authors from a selection of papers published in Journal of Experimental Biology and aims to promote not only the diversity of early-career researchers (ECRs) working in experimental biology but also the huge variety of animals and physiological systems that are essential for the ‘comparative’ approach. Harriet Goodrich is an author on ‘ Specific dynamic action as the energy cost of digestion or growth?’, published in JEB. Harriet is a lecturer in aquaculture production and aquatic animal physiology at the University of Tasmania, Australia, investigating how integrative, comparative and eco-physiology can be used as a tool to address global challenges in aquaculture production, fisheries management and conservation.

ECR Spotlight is a series of interviews with early-career authors from a selection of papers published in Journal of Experimental Biology and aims to promote not only the diversity of early-career researchers (ECRs) working in experimental biology during our centenary year but also the huge variety of animals and physiological systems that are essential for the ‘comparative’ approach. Lucas Greville and Mattina Alonge are authors on ‘ Acute restraint stress rapidly impacts reproductive neuroendocrinology and downstream gonad function in big brown bats (Eptesicus fuscus)’, published in JEB. Lucas is a Postdoctoral Researcher in the lab of Liam McGuire at the Department of Biology, University of Waterloo, Canada, investigating the eco-physiology of temperate bats with a focus on reproductive physiology and behaviour. Mattina is a Postdoctoral Researcher in the lab of Drs Helen Chmura and Creagh Breuner at the University of Montana, USA, investigating the dynamic interactions between the environment and reproductive physiology, and methods for differentiating pregnancy versus pseudopregnancy in lynx and wolverine within the (US) National Forest landscape.

IntroductionBioconvection, a phenomenon characterized by the collective upward swimming of motile microorganisms, has mainly been investigated within controlled laboratory settings, leaving a knowledge gap regarding its ecological implications in natural aquatic environments. This study aims to address this question by investigating the influence of bioconvection on the eco-physiology of the anoxygenic phototrophic sulfur bacteria community of meromictic Lake Cadagno.MethodsHere we comprehensively explore its effects by comparing the physicochemical profiles of the water column and the physiological traits of the main populations of the bacterial layer (BL). The search for eco-physiological effects of bioconvection involved a comparative analysis between two time points during the warm season, one featuring bioconvection (July) and the other without it (September).ResultsA prominent distinction in the physicochemical profiles of the water column centers on light availability, which is significantly higher in July. This minimum threshold of light intensity is essential for sustaining the physiological CO2 fixation activity of Chromatium okenii, the microorganism responsible for bioconvection. Furthermore, the turbulence generated by bioconvection redistributes sulfides to the upper region of the BL and displaces other microorganisms from their optimal ecological niches.ConclusionThe findings underscore the influence of bioconvection on the physiology of C. okenii and demonstrate its functional role in improving its metabolic advantage over coexisting phototrophic sulfur bacteria. However, additional research is necessary to confirm these results and to unravel the multiscale processes activated by C. okenii’s motility mechanisms.

ECR Spotlight is a series of interviews with early-career authors from a selection of papers published in Journal of Experimental Biology and aims to promote not only the diversity of early-career researchers (ECRs) working in experimental biology but also the huge variety of animals and physiological systems that are essential for the ‘comparative’ approach. Jessica Reemeyer is an author on ‘ Estimating maximum oxygen uptake of fishes during swimming and following exhaustive chase – different results, biological bases and applications’, published in JEB. Jessica is a PhD candidate in the lab of Lauren Chapman at McGill University, Canada, investigating the effects of environmental stressors on fishes and utilizing eco-physiology to inform their conservation.

Des sécheresses plus intenses et plus fréquentes sont attendues dans de nombreux écosystèmes selon les scénarios de changement climatique, tels que la région Méditerranéenne française et le bassin du Río de la Plata. Bien que les prairies naturelles et les pâturages aient toujours fait face à des épisodes de sécheresse, la capacité de résilience de ces communautés face à des sécheresses extrêmes a été peu étudiée. Par conséquent, les liens entre le fonctionnement des écosystèmes et les stratégies des espèces en cas de sécheresse intense méritent une attention particulière. Cette thèse comprendra trois chapitres principaux. Les deux premiers articles sont associés à une expérience climatique réalisée pour simuler les futurs étés plus secs d'un pâturage Méditerranéen sub-humide (La Fage, plateau du Larzac, France).Le premier article, au niveau communautaire, a identifié un point de basculement associé à la perte de résilience de ce pâturage. Une approche de modélisation a révélé un seuil de dégradation associé à une réduction de la couverture végétale à moins de 50 % dans les environnements les plus secs, indiquant une dégradation intense bien que l'impact de l'augmentation de la sécheresse sur la productivité de la biomasse et la qualité du fourrage soit resté limité. Un deuxième article rapporte la variabilité intraspécifique et la plasticité phénotypique de Bromopsis erecta l'année suivant la fin des traitements climatiques sur le terrain. Le déclin de l'abondance de cette graminée pérenne au fil du temps était associé à la capacité des plantes à maintenir la stabilité des membranes cellulaires à la base des feuilles, y compris les méristèmes, qui sont les organes de survie des graminées.Le troisième chapitre rapporte une étude sur les espèces de prairies de Campos du Río de la Plata, évaluées dans des conditions d'arrosage contrastées en Uruguay, tandis que les traits liés à l'eau de ces graminées ont été mesurés en France. Nous avons combiné des approches complémentaires en mesurant des traits de différents organes de la plante (limbes et bases des feuilles), mesurés dans des conditions standard et lors d'une courte période de dessèchement dans un jardin commun et sur le terrain lorsque possible. Nous avons étudié les relations de deux traits clés, la stabilité des membranes et la résistance à l'embolie, avec les stratégies de survie des graminées pérennes en cas de sécheresse. Cette étude intégrative fournira des connaissances pour mieux comprendre et gérer les écosystèmes de prairies et les graminées face au changement climatique
More intense and frequent droughts are expected in many ecosystems associated with climate change scenarios, such as the French Mediterranean area and the Río de la Plata basin. Although natural grasslands and rangelands have always faced drought events, the resilience capacity of these communities under extreme drought has been little studied. Consequently, the links between ecosystem functioning and the strategies of species under intense drought deserve attention. The thesis will include three main chapters. The first two articles are associated with a climate experiment that was carried out to mimic the future drier summers of a French sub-humid Mediterranean rangeland (La Fage, Larzac Plateau). The first article, at the community level, identified a tipping point associated with the loss of resilience of this rangeland. A modelling approach revealed a degradation threshold associated with a reduction of plant cover less than 50% in the driest environments that indicates an intense degradation although the impact of increased drought on biomass productivity and forage quality remained limited. A second article reports the intraspecific variability and phenotypic plasticity of Bromopsis erecta in the year following the end of field climate treatments. The decline in abundance of this perennial grass over time was associated with the ability of plants to maintain cell membrane stability on the leaf bases, including meristems, which are the survival organs of grasses. The third chapter reports a study with Campos grassland species from Río de la Plata, that were evaluated in contrasting watering conditions experiment in Uruguay, while water-related traits of these grasses were measured in Fance. We combined complementary approaches by measuring traits from different plant organs (leaf blades and leaf bases), measured in standard conditions and in a short dry-down period in common garden and in field whenever possible. We studied the relationships of two key traits, membrane stability and embolism resistance, with the plant drought survival strategies of perennial grasses. This integrative study will provide knowledge to understand and manage better grassland ecosystems and grasses under climate change