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1.
Science ; 369(6505): 838-841, 2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32792397

RESUMO

More than half of all tropical forests are degraded by human impacts, leaving them threatened with conversion to agricultural plantations and risking substantial biodiversity and carbon losses. Restoration could accelerate recovery of aboveground carbon density (ACD), but adoption of restoration is constrained by cost and uncertainties over effectiveness. We report a long-term comparison of ACD recovery rates between naturally regenerating and actively restored logged tropical forests. Restoration enhanced decadal ACD recovery by more than 50%, from 2.9 to 4.4 megagrams per hectare per year. This magnitude of response, coupled with modal values of restoration costs globally, would require higher carbon prices to justify investment in restoration. However, carbon prices required to fulfill the 2016 Paris climate agreement [$40 to $80 (USD) per tonne carbon dioxide equivalent] would provide an economic justification for tropical forest restoration.


Assuntos
Recuperação e Remediação Ambiental , Florestas , Clima Tropical , Agricultura , Biodiversidade , Dióxido de Carbono/metabolismo , Humanos
2.
Anesthesiology ; 133(3): 534-547, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32784343

RESUMO

BACKGROUND: According to the "three-compartment" model of ventilation-perfusion ((Equation is included in full-text article.)) inequality, increased (Equation is included in full-text article.)scatter in the lung under general anesthesia is reflected in increased alveolar deadspace fraction (VDA/VA) customarily measured using end-tidal to arterial (A-a) partial pressure gradients for carbon dioxide. A-a gradients for anesthetic agents such as isoflurane are also significant but have been shown to be inconsistent with those for carbon dioxide under the three-compartment theory. The authors hypothesized that three-compartment VDA/VA calculated using partial pressures of four inhalational agents (VDA/VAG) is different from that calculated using carbon dioxide (VDA/VACO2) measurements, but similar to predictions from multicompartment models of physiologically realistic "log-normal" (Equation is included in full-text article.)distributions. METHODS: In an observational study, inspired, end-tidal, arterial, and mixed venous partial pressures of halothane, isoflurane, sevoflurane, or desflurane were measured simultaneously with carbon dioxide in 52 cardiac surgery patients at two centers. VDA/VA was calculated from three-compartment model theory and compared for all gases. Ideal alveolar (PAG) and end-capillary partial pressure (Pc'G) of each agent, theoretically identical, were also calculated from end-tidal and arterial partial pressures adjusted for deadspace and venous admixture. RESULTS: Calculated VDA/VAG was larger (mean ± SD) for halothane (0.47 ± 0.08), isoflurane (0.55 ± 0.09), sevoflurane (0.61 ± 0.10), and desflurane (0.65 ± 0.07) than VDA/VACO2 (0.23 ± 0.07 overall), increasing with lower blood solubility (slope [Cis], -0.096 [-0.133 to -0.059], P < 0.001). There was a significant difference between calculated ideal PAG and Pc'G median [interquartile range], PAG 5.1 [3.7, 8.9] versus Pc'G 4.0[2.5, 6.2], P = 0.011, for all agents combined. The slope of the relationship to solubility was predicted by the log-normal lung model, but with a lower magnitude relative to calculated VDA/VAG. CONCLUSIONS: Alveolar deadspace for anesthetic agents is much larger than for carbon dioxide and related to blood solubility. Unlike the three-compartment model, multicompartment (Equation is included in full-text article.)scatter models explain this from physiologically realistic gas uptake distributions, but suggest a residual factor other than solubility, potentially diffusion limitation, contributes to deadspace.


Assuntos
Anestésicos Inalatórios/farmacocinética , Desflurano/farmacocinética , Halotano/farmacocinética , Isoflurano/farmacocinética , Alvéolos Pulmonares/metabolismo , Sevoflurano/farmacocinética , Idoso , Artérias/fisiologia , Dióxido de Carbono/metabolismo , Feminino , Humanos , Pulmão/metabolismo , Masculino , Pressão Parcial , Estudos Prospectivos , Estudos Retrospectivos
3.
Ecotoxicol Environ Saf ; 202: 110955, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800229

RESUMO

The effects of cadmium (Cd) have been investigated in an aquatic plant Ottelia alismoides grown under low CO2. Under low CO2, no Cd treated O. alismoides operated three carbon dioxide-concentrating mechanisms (CCMs) efficiently, including HCO3- acquisition, C4 and CAM photosynthesis. After 4 days of treatment with 200 µM and 2000 µM Cd, O. alismoides exhibited an elevated Cd accumulation along with the increasing Cd concentration. Both Cd treatments induced appreciable phytotoxicities in O. alismoides. The leaves showed chlorosis symptoms and the anatomy as well as chloroplast ultrastructure were obviously damaged. Significant decreases in the content of pigments, chlorophyll fluorescence (Fv/Fm and Yield of PS II) and carbon isotope ratio (δ13C) were measured in leaf extracts of O. alismoides grown with both concentrations of Cd. In addition, the pH-drift technique showed that both Cd-treated O. alismoides plants could not uptake HCO3-. The maximum and minimum acidity in Cd-exposed O. alismoides were greatly decreased and the diurnal change of acidity was absent in both Cd treated plants. Furthermore, significant decreases in ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), pyruvate phosphate dikinase (PPDK) and phosphoenolpyruvate carboxylase (PEPC) activities were also found at Cd treated O. alismoides plants, indicating the disturbance within C4 cycle. The alterations in the functionality of CCMs in O. alismoides induced by Cd might be related with the inhibition of the enzymes such as carbonic anhydrase (CA) and PEPC involved in inorganic carbon fixation, and the destruction of chloroplasts, as well as the re-allocation of energy and nutrients involved in CCMs and Cd detoxification.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Cádmio/toxicidade , Dióxido de Carbono/metabolismo , Hydrocharitaceae/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Organismos Aquáticos/metabolismo , Anidrases Carbônicas/metabolismo , Cloroplastos/metabolismo , Hydrocharitaceae/metabolismo , Ribulose-Bifosfato Carboxilase/metabolismo
4.
Am J Physiol Regul Integr Comp Physiol ; 319(3): R329-R342, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32697653

RESUMO

Peripheral chemosensitivity in fishes is thought to be mediated by serotonin-enriched neuroepithelial cells (NECs) that are localized to the gills of adults and the integument of larvae. In adult zebrafish (Danio rerio), branchial NECs are presumed to mediate the cardiorespiratory reflexes associated with hypoxia or hypercapnia, whereas in larvae, there is indirect evidence linking cutaneous NECs to hypoxic hyperventilation and hypercapnic tachycardia. No study yet has examined the ventilatory response of larval zebrafish to hypercapnia, and regardless of developmental stage, the signaling pathways involved in CO2 sensing remain unclear. In the mouse, a background potassium channel (TASK-2) contributes to the sensitivity of chemoreceptor cells to CO2. Zebrafish possess two TASK-2 channel paralogs, TASK-2 and TASK-2b, encoded by kcnk5a and kcnk5b, respectively. The present study aimed to determine whether TASK-2 channels are expressed in NECs of larval zebrafish and whether they are involved in CO2 sensing. Using immunohistochemical approaches, TASK-2 protein was observed on the surface of NECs in larvae. Exposure of larvae to hypercapnia caused cardiac and breathing frequencies to increase, and these responses were blunted in fish experiencing TASK-2 and/or TASK-2b knockdown. The results of these experiments suggest that TASK-2 channels are involved in CO2 sensing by NECs and contribute to the initiation of reflex cardiorespiratory responses during exposure of larvae to hypercapnia.


Assuntos
Dióxido de Carbono/metabolismo , Hipercapnia/metabolismo , Hipóxia/metabolismo , Células Neuroepiteliais/metabolismo , Canais de Potássio de Domínios Poros em Tandem/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Animais , Células Quimiorreceptoras/metabolismo , Brânquias/metabolismo , Hiperventilação/metabolismo , Células Neuroepiteliais/citologia , Oxigênio/metabolismo , Peixe-Zebra/fisiologia
5.
Nature ; 583(7816): 453-458, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32669693

RESUMO

Manganese is one of the most abundant elements on Earth. The oxidation of manganese has long been theorized1-yet has not been demonstrated2-4-to fuel the growth of chemolithoautotrophic microorganisms. Here we refine an enrichment culture that exhibits exponential growth dependent on Mn(II) oxidation to a co-culture of two microbial species. Oxidation required viable bacteria at permissive temperatures, which resulted in the generation of small nodules of manganese oxide with which the cells associated. The majority member of the culture-which we designate 'Candidatus Manganitrophus noduliformans'-is affiliated to the phylum Nitrospirae (also known as Nitrospirota), but is distantly related to known species of Nitrospira and Leptospirillum. We isolated the minority member, a betaproteobacterium that does not oxidize Mn(II) alone, and designate it Ramlibacter lithotrophicus. Stable-isotope probing revealed 13CO2 fixation into cellular biomass that was dependent upon Mn(II) oxidation. Transcriptomic analysis revealed candidate pathways for coupling extracellular manganese oxidation to aerobic energy conservation and autotrophic CO2 fixation. These findings expand the known diversity of inorganic metabolisms that support life, and complete a biogeochemical energy cycle for manganese5,6 that may interface with other major global elemental cycles.


Assuntos
Bactérias/metabolismo , Crescimento Quimioautotrófico , Manganês/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Ciclo do Carbono , Dióxido de Carbono/metabolismo , Técnicas de Cocultura , Perfilação da Expressão Gênica , Isótopos , Manganês/química , Compostos de Manganês/química , Compostos de Manganês/metabolismo , Oxirredução , Óxidos/química , Óxidos/metabolismo , Filogenia
6.
PLoS One ; 15(7): e0235817, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32678858

RESUMO

Whether marine fish will grow differently in future high pCO2 environments remains surprisingly uncertain. Long-term and whole-life cycle effects are particularly unknown, because such experiments are logistically challenging, space demanding, exclude long-lived species, and require controlled, restricted feeding regimes-otherwise increased consumption could mask potential growth effects. Here, we report on repeated, long-term, food-controlled experiments to rear large populations (>4,000 individuals total) of the experimental model and ecologically important forage fish Menidia menidia (Atlantic silverside) under contrasting temperature (17°, 24°, and 28°C) and pCO2 conditions (450 vs. ~2,200 µatm) from fertilization to ~ a third of this annual species' life span. Quantile analyses of trait distributions showed mostly negative effects of high pCO2 on long-term growth. At 17°C and 28°C, but not at 24°C, high pCO2 fish were significantly shorter [17°C: -5 to -9%; 28°C: -3%] and weighed less [17°C: -6 to -18%; 28°C: -8%] compared to ambient pCO2 fish. Reductions in fish weight were smaller than in length, which is why high pCO2 fish at 17°C consistently exhibited a higher Fulton's k (weight/length ratio). Notably, it took more than 100 days of rearing for statistically significant length differences to emerge between treatment populations, showing that cumulative, long-term CO2 effects could exist elsewhere but are easily missed by short experiments. Long-term rearing had another benefit: it allowed sexing the surviving fish, thereby enabling rare sex-specific analyses of trait distributions under contrasting CO2 environments. We found that female silversides grew faster than males, but there was no interaction between CO2 and sex, indicating that males and females were similarly affected by high pCO2. Because Atlantic silversides are known to exhibit temperature-dependent sex determination, we also analyzed sex ratios, revealing no evidence for CO2-dependent sex determination in this species.


Assuntos
Dióxido de Carbono/análise , Peixes/crescimento & desenvolvimento , Animais , Dióxido de Carbono/metabolismo , Mudança Climática , Feminino , Masculino , Água do Mar/análise , Processos de Determinação Sexual , Diferenciação Sexual , Temperatura
7.
PLoS One ; 15(6): e0235125, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32574214

RESUMO

Crustose coralline algae (CCA) are vital to coral reefs worldwide, providing structural integrity and inducing the settlement of important invertebrate larvae. CCA are known to be impacted by changes in their environment, both during early development and adulthood. However, long-term studies on either life history stage are lacking in the literature, therefore not allowing time to explore the acclimatory or potential adaptive responses of CCA to future global change scenarios. Here, we exposed a widely distributed, slow growing, species of CCA, Sporolithon cf. durum, to elevated temperature and pCO2 for five months and their first set of offspring (F1) for eleven weeks. Survival, reproductive output, and metabolic rate were measured in adult S. cf. durum, and survival and growth were measured in the F1 generation. Adult S. cf. durum experienced 0% mortality across treatments and reduced their O2 production after five months exposure to global stressors, indicating a possible expression of plasticity. In contrast, the combined stressors of elevated temperature and pCO2 resulted in 50% higher mortality and 61% lower growth on germlings. On the other hand, under the independent elevated pCO2 treatment, germling growth was higher than all other treatments. These results show the robustness and plasticity of S. cf. durum adults, indicating the potential for them to acclimate to increased temperature and pCO2. However, the germlings of this species are highly sensitive to global stressors and this could negatively impact this species in future oceans, and ultimately the structure and stability of coral reefs.


Assuntos
Antozoários/crescimento & desenvolvimento , Dióxido de Carbono/metabolismo , Recifes de Corais , Estágios do Ciclo de Vida , Rodófitas/crescimento & desenvolvimento , Temperatura , Adaptação Fisiológica , Animais , Mudança Climática , Ecossistema , Concentração de Íons de Hidrogênio , Oceanos e Mares , Rodófitas/metabolismo , Água do Mar , Fatores de Tempo
8.
Chemosphere ; 259: 127418, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32574848

RESUMO

This work evaluated the effect of different initial biomass ratios in a co-culture of an alkaliphilic methanotrophic bacteria consortium (AMB) and the green microalga Scenedesmus obtusiusculus (GM) on the maximum CH4 specific biodegradation rate and global carbon uptake. The highest maximum specific biodegradation rate was 589 ± 0.01 mgCH4 gbiomass-1 d-1 obtained for a proportion of 3:1 AMB-GM (w w-1) and 8% of initial CH4 in the headspace. The methane degradation rate was 1.5 times lower than the value obtained solely by the AMB consortium, and it was associated with pH increases due to the evolved CO2 consumption by the microalga. Increased activity of the AMB consortium along the experiments was due to progressive adaptation. Massive sequencing revealed the presence of methanotrophic/methylotrophic species such as Methylocystis sp., Methylomicrobium sp., Methylophaga sp., and Hyphomicrobium sp. Successful complete methane and carbon dioxide uptake was obtained with the 3:1, 4:1, and 5:1 AMB-GM biomass ratios, while for the rest of the ratios tested, more than 70% of the initial methane was transformed into biomass and inorganic carbon. This study showed that methanotrophic-microalgal co-cultures lead to a promising strategy for greenhouse gases mitigation in one step.


Assuntos
Biodegradação Ambiental , Gases de Efeito Estufa , Metano/metabolismo , Microalgas/fisiologia , Biomassa , Dióxido de Carbono/metabolismo , Técnicas de Cocultura , Methylocystaceae , Microalgas/metabolismo , Scenedesmus/metabolismo
9.
Life Sci ; 257: 117994, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32569780

RESUMO

Sleep-disordered breathing is characterized by disruptions of normal breathing patterns during sleep. Obesity is closely related to hypoventilation or apnea and becomes a primary risk factor for sleep-disordered breathing. Leptin, a peptide secreted by adipose tissue, has been implicated in central control of breathing. Activation of the retrotrapezoid nucleus (RTN) neurons, a critical central respiratory chemoreceptor candidate, potentiates a central drive to breathing. Here, we ask whether the disordered leptin signaling in the RTN is responsible for obesity-related hypoventilation. In a diet induced obesity (DIO) mouse model, the hypercapnic ventilatory response (HCVR) was assessed and the cellular leptin signaling in the RTN was examined. Our main findings demonstrate that DIO mice exhibit overweight, hypercapnia, high levels of serum and cerebrospinal leptin. During exposure to room air, DIO mice manifest basal hypoventilation with a rapid and shallow breathing pattern. Exposure to CO2 elicits the impaired HCVR in DIO mice. In addition, both the number of CO2-activated neurons and expression of TASK-2 channels in the RTN are dramatically reduced in DIO mice. Moreover, there is leptin signaling disorder in RTN neurons in DIO mice, including a significant decrease in leptin-activated RTN neurons, downregulation of phosphorylated STAT3 and upregulation of SOCS3. Altogether, we suggest that the disordered leptin/STAT3/SOCS3 signaling pathway in the RTN plays a role in obesity-related hypoventilation.


Assuntos
Células Quimiorreceptoras/metabolismo , Leptina/metabolismo , Obesidade/metabolismo , Animais , Dióxido de Carbono/metabolismo , Células Quimiorreceptoras/fisiologia , Hipercapnia/metabolismo , Leptina/fisiologia , Masculino , Bulbo/metabolismo , Bulbo/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Obesidade/fisiopatologia , Respiração , Mecânica Respiratória/fisiologia , Transdução de Sinais , Sono/fisiologia
10.
Ultrasonics ; 108: 106198, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32590261

RESUMO

Contrast-enhanced ultrasound (CEUS) is widely applied in cancer diagnosis clinically. However, the gas-filled contrast agents are unstable in the blood and exhibit shorter imaging time, which limit their clinical use. In this study, a diagnostic nanoparticle system was developed for dual-mode imaging (ultrasound and fluorescence), which after encapsulation with doxorubicin (DOX) demonstrated simultaneous therapeutic function towards cancer treatment. Thus, calcium carbonate (CaCO3) nanoparticles were encapsulated with doxorubicin (DOX) to obtain CaCO3-DOX. Under acidic conditions, it produced carbon dioxide (CO2) to enhance ultrasound imaging and increase the release of DOX. After intravenously injecting CaCO3-DOX to tumor-bearing mice, in the presence of an ultrasound field, CO2bubbles were sufficiently generated at the tumor tissues for echogenic reflectivity. Also, the indocyanine green (ICG) was encapsulated into CaCO3 nanoparticles, to further detect the tumor with fluorescence. The resultant theranostic nanoparticle system exhibited therapeutic efficacy towards tumour-bearing mice. Overall, this investigation provides an attractive strategy for dual-mode cancer diagnostics.


Assuntos
Carbonato de Cálcio/farmacologia , Doxorrubicina/farmacologia , Imagem Multimodal , Neoplasias Experimentais/diagnóstico por imagem , Neoplasias Experimentais/tratamento farmacológico , Nanomedicina Teranóstica/métodos , Ultrassonografia/métodos , Animais , Carbonato de Cálcio/química , Dióxido de Carbono/metabolismo , Linhagem Celular Tumoral , Meios de Contraste , Doxorrubicina/química , Portadores de Fármacos/química , Portadores de Fármacos/farmacologia , Fluorescência , Concentração de Íons de Hidrogênio , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Nanopartículas/química , Microambiente Tumoral
12.
Food Chem ; 328: 127102, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-32512468

RESUMO

Sprouting process enhances plant bioactive compounds. Broccoli (Brassica oleracea L) sprouts are well known for their high levels of glucosinolates (GLs), amino acids, and antioxidants, which offer outstanding biological activities with positive impacts on plant metabolism. Elevated CO2 (eCO2, 620 ppm) was applied for 9 days to further improve nutritive and health-promoting values of three cultivars of broccoli sprouts i.e., Southern star, Prominence and Monotop. eCO2 improved sprouts growth and induced GLs accumulation e.g., glucoraphanin, possibly through amino acids production e.g., high methionine and tryptophan. There were increases in myrosinase activity, which stimulated GLs hydrolysis to yield health-promoting sulforaphane. Interestingly, low levels of ineffective sulforaphane nitrile were detected and positively correlated with reduced epithiospecifier protein after eCO2 treatment. High glucoraphanin and sulforaphane levels in eCO2 treated sprouts improved the anticarcinogenic and anti-inflammatory properties of their extracts. In conclusion, eCO2 treatment enriches broccoli sprouts with health-promoting metabolites and bioactivities.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Brassica/metabolismo , Dióxido de Carbono/metabolismo , Glucosinolatos/metabolismo , Aminoácidos/metabolismo , Anti-Inflamatórios/farmacologia , Brassica/química , Brassica/crescimento & desenvolvimento , Linhagem Celular , Glucosinolatos/farmacologia , Humanos , Imidoésteres/metabolismo , Imidoésteres/farmacologia , Isotiocianatos/metabolismo , Isotiocianatos/farmacologia , Extratos Vegetais/farmacologia
13.
PLoS One ; 15(6): e0234994, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32598370

RESUMO

Estuaries are characterized by high fluctuation of their environmental conditions. Environmental parameters measured show that the seawater properties of the Quempillén estuary (i.e. temperature, salinity, pCO2, pH and ΩCaCO3) were highly fluctuating and related with season and tide. We test the effects of increasing temperature and pCO2 in the seawater on the physiological energetics of the bivalve Ostrea chilensis. Juvenile oysters were exposed to an orthogonal combination of three temperatures (10, 15, and 20°C) and two pCO2 levels (~400 and ~1000 µatm) for a period of 60 days to evaluate the temporal effect (i.e. 10, 20, 30, 60 days) on the physiological rates of the oysters. Results indicated a significant effect of temperature and time of exposure on the clearance rate, while pCO2 and the interaction between pCO2 and the other factors studied did not show significant effects. Significant effects of temperature and time of exposure were also observed on the absorption rate, but not the pCO2 nor its interaction with other factors studied. Oxygen consumption was significantly affected by pCO2, temperature and time. Scope for growth was only significantly affected by time; despite this, the highest values were observed for individuals subject to to 20°C and to ~1000 µatm pCO2. In this study, Ostrea chilensis showed high phenotypic plasticity to respond to the high levels of temperature and pCO2 experienced in its habitat as no negative physiological effects were observed. Thus, the highly variable conditions of this organism's environment could select for individuals that are more resistant to future scenarios of climate change, mainly to warming and acidification.


Assuntos
Aclimatação , Variação Biológica da População , Exposição Ambiental/efeitos adversos , Ostrea/fisiologia , Água do Mar/química , Animais , Dióxido de Carbono/análise , Dióxido de Carbono/metabolismo , Chile , Mudança Climática , Temperatura Alta/efeitos adversos , Concentração de Íons de Hidrogênio , Consumo de Oxigênio , Salinidade
14.
Life Sci ; 256: 117922, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32522569

RESUMO

To test the hypothesis of STC-1 participation in maintenance of glucose homeostasis in fed and fasting (48 h) rats, we investigated that this hormone may be implicated in the regulation of renal gluconeogenesis pathway from lactate and lactate oxidation in renal cortex and medulla. Our results demonstrate the hSTC-1 role on lactate metabolism in the renal cortex and medulla from fed and fasting rats. hSTC-1 increased the gluconeogenesis activity in fed state in renal cortex, and this increase was induced by raise in Pck1 gene expression. In fasting animals hSTC-1 increase the renal medulla gluconeogenesis activity, but Pck1 gene expression was not alter. The stimulatory effect of hSTC-1 on 14C-lactate oxidation occurred only in the renal cortex from fed rats. These findings show the hSTC-1 contribution to lactate homeostasis and supplies glucose to other tissues. This response may represent a strategy of action of STC-1 in response to fasting stress as postulated by different authors. On the other hand, hSTC-1 acts downstream of adenylcyclase pathway, decreasing the gluconeogenesis activity induced by cAMP intracellular increase or stimulating the phosphodiesterase activity in the renal cortex. However, no hSTC-1 effect on 14C-lactate oxidation was found after increase in the intracellular cAMP. The findings also revealed that the renal cortex and medulla respond differently to hSTC-1, possibly due to the higher level of STC-1 gene expression in inner renal medulla than in renal cortex.


Assuntos
Gluconeogênese/efeitos dos fármacos , Glicoproteínas/metabolismo , Hormônios/metabolismo , Rim/metabolismo , Lactatos/metabolismo , Proteínas Recombinantes/metabolismo , Adenilil Ciclases/metabolismo , Animais , Dióxido de Carbono/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Regulação da Expressão Gênica , Glucose/metabolismo , Glicoproteínas/genética , Hormônios/genética , Humanos , Córtex Renal/metabolismo , Medula Renal/metabolismo , Masculino , Oxirredução , Diester Fosfórico Hidrolases/metabolismo , Ratos , Ratos Wistar , Proteínas Recombinantes/genética , Transdução de Sinais
15.
Nat Commun ; 11(1): 2999, 2020 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-32532992

RESUMO

Recent studies show coordinated relationships between plant leaf traits and their capacity to predict ecosystem functions. However, how leaf traits will change within species and whether interspecific trait relationships will shift under future environmental changes both remain unclear. Here, we examine the bivariate correlations between leaf economic traits of 515 species in 210 experiments which mimic climate warming, drought, elevated CO2, and nitrogen deposition. We find divergent directions of changes in trait-pairs between species, and the directions mostly do not follow the interspecific trait relationships. However, the slopes in the logarithmic transformed interspecific trait relationships hold stable under environmental changes, while only their elevations vary. The elevation changes of trait relationship are mainly driven by asymmetrically interspecific responses contrary to the direction of the leaf economic spectrum. These findings suggest robust interspecific trait relationships under global changes, and call for linking within-species responses to interspecific coordination of plant traits.


Assuntos
Mudança Climática , Ecossistema , Aquecimento Global , Folhas de Planta/metabolismo , Plantas/metabolismo , Algoritmos , Dióxido de Carbono/metabolismo , Secas , Modelos Biológicos , Nitrogênio/metabolismo , Fenótipo , Folhas de Planta/anatomia & histologia , Plantas/anatomia & histologia , Plantas/classificação , Especificidade da Espécie
16.
Plant Mol Biol ; 104(1-2): 55-65, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32572798

RESUMO

Increase in atmospheric carbon dioxide (CO2) has a significant effect on plant growth and development. To explore the elevated-CO2 response, we generated transcriptional profiles over a time course (2 h-14 days) of exposure to elevated CO2 in Arabidopsis thaliana. Genes related to photosynthesis were down-regulated and circadian rhythm-related genes were abnormally regulated in the early to middle phase of elevated CO2 exposure. To understand the novel mechanism of elevated CO2 signaling, we focused on 42 unknown small coding genes that showed differential expression patterns under elevated CO2 conditions. Four transgenic plants overexpressing the small coding gene exhibited a growth-defective phenotype under elevated CO2 but not under current CO2. Transcriptome analysis showed that circadian rhythm-related genes were commonly regulated in four transgenic plants. These circadian rhythm-related genes were transcribed in the dark when CO2 concentrations in the leaf was high. Taken together, our identified four small coding genes are likely to participate in elevated CO2 signaling to the circadian rhythm.


Assuntos
Arabidopsis/genética , Arabidopsis/metabolismo , Dióxido de Carbono/metabolismo , Ritmo Circadiano/genética , Ritmo Circadiano/fisiologia , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação para Baixo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Fenótipo , Fotossíntese/genética , Desenvolvimento Vegetal , Folhas de Planta/genética , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , RNA de Plantas/genética , RNA de Plantas/isolamento & purificação , Transcriptoma
17.
PLoS One ; 15(5): e0233303, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32437419

RESUMO

This study compares thirteen rice-based cropping systems in the coastal part of West Bengal, India in terms of productivity, profitability, energetics, and emissions. Information on the crop management practices of these systems was collected on 60 farms through a questionnaire survey. Rice-bitter gourd system was observed to have the highest system yield (49.88 ± 4.34 tha-1yr-1) followed by rice-potato-ridge gourd (37.78 ± 2.77 tha-1yr-1) and rice-potato-pumpkin (36.84 ± 2.04 tha-1yr-1) systems. The rice-bitter gourd system also recorded the highest benefit:cost ratio (3.92 ± 0.061). The lowest system yield and economics were recorded in the rice-fallow-fallow system. Rice-sunflower system recorded highest specific energy (2.54 ± 0.102 MJkg-1), followed by rice-rice (2.14 ± 0.174 MJkg-1) and rice-fallow-fallow (1.91 ± 0.327 MJkg-1) systems, lowest being observed in the rice-bitter gourd (0.52 ± 0.290 MJkg-1) and rice-pointed gourd (0.52 ± 0.373 MJkg-1) systems. Yield-scaled GHGs (YSGHG) emission was highest (1.265 ± 0.29 t CO2eqt-1 system yield) for rice-fallow-fallow system and was lowest for rice-vegetable systems. To estimate the uncertainty of the YSGHG across different systems under study, Monte-Carlo Simulation was performed. It was observed that there was a 5% probability of recording YSGHG emission > 1.15 t CO2eqt-1 system yield from different cropping systems in the present experiment. Multiple system properties such as productivity, economics, energy, and emission from all rice-based systems taken together, the rice-vegetable system performed consistently well across parameters and may be practised for higher economic returns with judicious and sustainable utilization of resources in the coastal saline tracts of the region.


Assuntos
Produtos Agrícolas/economia , Gases de Efeito Estufa/metabolismo , Oryza/metabolismo , Dióxido de Carbono/metabolismo , Mudança Climática/economia , Simulação por Computador , Produção Agrícola/economia , Produção Agrícola/métodos , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/metabolismo , Índia , Metano/metabolismo , Método de Monte Carlo , Óxido Nitroso/metabolismo , Oryza/crescimento & desenvolvimento , Medição de Risco , Salinidade
20.
PLoS Comput Biol ; 16(5): e1007841, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32384085

RESUMO

Light is one of the factors that can play a role in bacterial infiltration into leafy greens by keeping stomata open and providing photosynthetic products for microorganisms. We model chemotactic transport of bacteria within a leaf tissue in response to photosynthesis occurring within plant mesophyll. The model includes transport of carbon dioxide, oxygen, bicarbonate, sucrose/glucose, bacteria, and autoinducer-2 within the leaf tissue. Biological processes of carbon fixation in chloroplasts, and respiration in mitochondria of the plant cells, as well as motility, chemotaxis, nutrient consumption and communication in the bacterial community are considered. We show that presence of light is enough to boost bacterial chemotaxis through the stomatal opening and toward photosynthetic products within the leaf tissue. Bacterial chemotactic ability is a major player in infiltration, and plant stomatal defense in closing the stomata as a perception of microbe-associated molecular patterns is an effective way to inhibit the infiltration.


Assuntos
Fenômenos Fisiológicos Bacterianos , Quimiotaxia , Luz , Modelos Biológicos , Estômatos de Plantas/microbiologia , Dióxido de Carbono/metabolismo , Estômatos de Plantas/fisiologia
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