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1.
Arch Biochem Biophys ; 690: 108471, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32622788

RESUMO

Stilbenes, an active substances closely related to resistance and quality of grapes, are rarely found in natural resources. However its cumulative amount is affected by ultraviolet radiation (UV). The purpose of this study is to screen key genes in biosynthesis of stilbenes Trans-scripusin A and explore its synthetic pathway. We tested content of stilbenes with UHPLC-QQQ-MS2, results revealed that stilbenes accumulation is positively correlated with UV-B exposure time. Then, we performed transcriptome high-throughput sequencing of grapes under treatments. Results shown that 13,906 differentially expressed genes were obtained, which were mainly enriched in three major regions (ribosome, plant-pathogen interaction and biosynthesis of flavonoid). Three genes of trans-scripusin A synthesis pathway key got by combining KEGG annotation and reference gene HsCYP1B1. Phylogenetic analysis showed that SAH genes had high homology with other hydroxylase genes, and distributed in two subgroups. Gene structure analysis showed that SAH genes contained four exons, indicating that gene has low genetic diversity. Chromosome localization revealed that SAH genes were distributed on different chromosomes, in addition, the number of gene pairs between Vitis vinifera and other species was not related to genome size of other species. The expression profiles of SAH genes in different parts of Vitis vinifera L. were analyzed using qRT-PCR analysis, results indicated that expression of SAH genes be specific to fruit part. These paper provide theoretical basis for further study of polyphenols biosynthesis pathway in grape fruits. The study provides novel insights for further understanding quality of grapes response to UV radiation.


Assuntos
Frutas/genética , Regulação da Expressão Gênica de Plantas/efeitos da radiação , RNA Mensageiro/efeitos da radiação , Vitis/genética , Vias Biossintéticas , Cromatografia Líquida de Alta Pressão , Flavonoides/metabolismo , Frutas/metabolismo , Frutas/efeitos da radiação , Ensaios de Triagem em Larga Escala , Conformação de Ácido Nucleico , Filogenia , Polifenóis/metabolismo , RNA-Seq , Ribossomos/metabolismo , Estilbenos/metabolismo , Estresse Fisiológico/genética , Estresse Fisiológico/efeitos da radiação , Espectrometria de Massas em Tandem , Transcriptoma/efeitos da radiação , Raios Ultravioleta , Vitis/metabolismo , Vitis/efeitos da radiação
2.
Sci Rep ; 10(1): 3321, 2020 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-32094353

RESUMO

Fluorescent light (FL) has been shown to induce a cellular immune and inflammatory response that is conserved over 450 MY of evolutionary divergence and among vertebrates having drastically different lifestyles such as Mus musculus, Danio rerio, Oryzias latipes and Xiphophorus maculatus. This surprising finding of an inflammation and immune response to FL not only holds for direct light receiving organs (skin) but is also observed within internal organs (brain and liver). Light responsive genetic circuitry initiated by the IL1B regulator induces a highly conserved acute phase response in each organ assessed for all of biological models surveyed to date; however, the specific light wavelengths triggering this response have yet to be determined so investigation of mechanisms and/or light specific molecule(s) leading to this response are difficult to assess. To understand how specific light wavelengths are received in both external and internal organs, zebrafish were exposed to specific 50 nm light wavebands spanning the visible spectrum from 300-600 nm and the genetic responses to each waveband exposure were assessed. Surprisingly, the induced cellular stress response previously observed following FL exposure is not triggered by the lower "damaging" wavelengths of light (UVB and UVA from 300-400 nm) but instead is maximally induced by higher wavelengths ranging from 450-500 nm in skin to 500-600 nm in both brain and liver).


Assuntos
Inflamação/patologia , Luz , Estresse Fisiológico/efeitos da radiação , Peixe-Zebra/fisiologia , Animais , Encéfalo/metabolismo , Encéfalo/efeitos da radiação , Fluorescência , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Fígado/metabolismo , Fígado/efeitos da radiação , Pele/metabolismo , Pele/efeitos da radiação , Espectrometria de Fluorescência , Peixe-Zebra/genética
3.
Environ Pollut ; 259: 113895, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31926393

RESUMO

Artificial light at night (ALAN) can disrupt adaptive patterns of physiology and behavior that promote high fitness, resulting in physiological stress and elevation of steroid glucocorticoids (corticosterone, CORT in birds). Elevated CORT may have particularly profound effects early in life, with the potential for enduring effects that persist into adulthood. Research on the consequences of early-life exposure to ALAN remains limited, especially outside of the laboratory, and whether light exposure affects CORT concentrations in wild nestling birds particularly remains to be elucidated. We used an experimental setup to test the hypothesis that ALAN elevates CORT concentrations in developing free-living birds, by exposing nestling great tits (Parus major) to ALAN inside nest boxes. We measured CORT in feathers grown over the timeframe of the experiment (7 nights), such that CORT concentrations represent an integrative metric of hormone release over the period of nocturnal light exposure, and of development. We also assessed the relationships between feather CORT concentrations, body condition, nestling size rank and fledging success. In addition, we evaluated the relationship between feather CORT concentrations and telomere length. Nestlings exposed to ALAN had higher feather CORT concentrations than control nestlings, and nestlings in poorer body condition and smaller brood members also had higher CORT. On the other hand, telomere length, fledging success, and recruitment rate were not significantly associated with light exposure or feather CORT concentrations. Results indicate that exposure to ALAN elevates CORT concentrations in nestlings, which may reflect physiological stress. In addition, the organizational effects of CORT are known to be substantial. Thus, despite the lack of an effect on telomere length and survivorship, elevated CORT concentrations in nestlings exposed to ALAN may have subsequent impacts on later-life fitness and stress sensitivity.


Assuntos
Exposição Ambiental , Luz , Aves Canoras , Estresse Fisiológico , Animais , Corticosterona/análise , Exposição Ambiental/efeitos adversos , Plumas/química , Aves Canoras/fisiologia , Estresse Fisiológico/efeitos da radiação
4.
Curr Issues Mol Biol ; 38: 103-122, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31967578

RESUMO

Five bacterial (facultatively) anaerobic strains, namely Buttiauxella sp. MASE-IM-9, Clostridium sp. MASE-IM-4, Halanaerobium sp. MASE-BB-1, Trichococcus sp. MASE-IM-5, and Yersinia intermedia MASE-LG-1 isolated from different extreme natural environments were subjected to Mars relevant environmental stress factors in the laboratory under controlled conditions. These stress factors encompassed low water activity, oxidizing compounds, and ionizing radiation. Stress tests were performed under permanently anoxic conditions. The survival rate after addition of sodium perchlorate (Na-perchlorate) was found to be species-specific. The inter-comparison of the five microorganisms revealed that Clostridium sp. MASE-IM-4 was the most sensitive strain (D10-value (15 min, NaClO4) = 0.6 M). The most tolerant microorganism was Trichococcus sp. MASE-IM-5 with a calculated D10-value (15 min, NaClO4) of 1.9 M. Cultivation in the presence of Na-perchlorate in Martian relevant concentrations up to 1 wt% led to the observation of chains of cells in all strains. Exposure to Na-perchlorate led to a lowering of the survival rate after desiccation. Consecutive exposure to desiccating conditions and ionizing radiation led to additive effects. Moreover, in a desiccated state, an enhanced radiation tolerance could be observed for the strains Clostridium sp. MASE-IM-4 and Trichococcus sp. MASE-IM-5. These data show that anaerobic microorganisms from Mars analogue environments can resist a variety of Martian-simulated stresses either individually or in combination. However, responses were species-specific and some Mars-simulated extremes killed certain organisms. Thus, although Martian stresses would be expected to act differentially on microorganisms, none of the expected extremes tested here and found on Mars prevent the growth of anaerobic microorganisms.


Assuntos
Bactérias Anaeróbias/crescimento & desenvolvimento , Meio Ambiente Extraterreno , Ambientes Extremos , Bactérias Anaeróbias/efeitos dos fármacos , Bactérias Anaeróbias/efeitos da radiação , Carnobacteriaceae/efeitos dos fármacos , Carnobacteriaceae/crescimento & desenvolvimento , Carnobacteriaceae/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Clostridium/efeitos dos fármacos , Clostridium/crescimento & desenvolvimento , Clostridium/efeitos da radiação , Dessecação , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/crescimento & desenvolvimento , Enterobacteriaceae/efeitos da radiação , Firmicutes/efeitos dos fármacos , Firmicutes/crescimento & desenvolvimento , Firmicutes/efeitos da radiação , Marte , Estresse Oxidativo , Percloratos/toxicidade , Tolerância a Radiação , Compostos de Sódio/toxicidade , Estresse Fisiológico/efeitos da radiação , Fatores de Tempo , Yersinia/efeitos dos fármacos , Yersinia/crescimento & desenvolvimento , Yersinia/efeitos da radiação
5.
Biochim Biophys Acta Bioenerg ; 1861(4): 148014, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30880080

RESUMO

The spring ephemeral Berteroa incana is a familial relative of Arabidopsis thaliana and thrives in a diverse range of terrestrial ecosystems. Within this study, the novel chlorophyll fluorescence parameter of photochemical quenching in the dark (qPd) was used to measure the redox state of the primary quinone electron acceptor (QA) in order to estimate the openness of photosystem II (PSII) reaction centres (RC). From this, the early onset of photoinactivation can be sensitively quantified alongside the light tolerance of PSII and the photoprotective efficiency of nonphotochemical quenching (NPQ). This study shows that, with regards to A. thaliana, NPQ is enhanced in B. incana in both low-light (LL) and high-light (HL) acclimation states. Moreover, light tolerance is increased by up to 500%, the rate of photoinactivation is heavily diminished, and the ability to recover from light stress is enhanced in B. incana, relative to A. thaliana. This is due to faster synthesis of zeaxanthin and a larger xanthophyll cycle (XC) pool available for deepoxidation. Moreover, preferential energy transfer via CP47 around the RC further enhances efficient photoprotection. As a result, a high functional cross-section of photosystem II is maintained and is not downregulated when B. incana is acclimated to HL. A greater capacity for protective NPQ allows B. incana to maintain an enhanced light-harvesting capability when acclimated to a range of light conditions. This enhancement of flexible short-term protection saves the metabolic cost of long-term acclimatory changes.


Assuntos
Aclimatação/fisiologia , Brassicaceae/fisiologia , Processos Fotoquímicos , Estações do Ano , Aclimatação/efeitos da radiação , Arabidopsis/fisiologia , Arabidopsis/efeitos da radiação , Brassicaceae/efeitos da radiação , Transferência de Energia , Cinética , Luz , Complexo de Proteína do Fotossistema II/metabolismo , Espectrometria de Fluorescência , Estresse Fisiológico/efeitos da radiação , Regulação para Cima/efeitos da radiação , Xantofilas/metabolismo , Zeaxantinas/biossíntese
6.
Biochim Biophys Acta Bioenerg ; 1861(4): 148037, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-31228405

RESUMO

Photosynthetic organisms need to sense and respond to fluctuating environmental conditions, to perform efficient photosynthesis and avoid the formation of harmful reactive oxygen species. Cyanobacteria have developed a photoprotective mechanism that decreases the energy arriving at the reaction centers by increasing thermal energy dissipation at the level of the phycobilisome, the extramembranal light-harvesting antenna. This mechanism is triggered by the photoactive orange carotenoid protein (OCP). In this study, we characterized OCP and the related photoprotective mechanism in non-stressed and light-stressed cells of three different strains of Planktothrix that can form impressive blooms. In addition to changing lake ecosystemic functions and biodiversity, Planktothrix blooms can have adverse effects on human and animal health as they produce toxins (e.g., microcystins). Three Planktothrix strains were selected: two green strains, PCC 10110 (microcystin producer) and PCC 7805 (non-microcystin producer), and one red strain, PCC 7821. The green strains colonize shallow lakes with higher light intensities while red strains proliferate in deep lakes. Our study allowed us to conclude that there is a correlation between the ecological niche in which these strains proliferate and the rates of induction and recovery of OCP-related photoprotection. However, differences in the resistance to prolonged high-light stress were correlated to a better replacement of damaged D1 protein and not to differences in OCP photoprotection. Finally, microcystins do not seem to be involved in photoprotection as was previously suggested.


Assuntos
Proteínas de Bactérias/metabolismo , Cianobactérias/fisiologia , Cianobactérias/efeitos da radiação , Luz , Estresse Fisiológico/efeitos da radiação , Proteínas de Bactérias/genética , Proteínas de Bactérias/ultraestrutura , Cianobactérias/genética , Cianobactérias/ultraestrutura , Regulação Bacteriana da Expressão Gênica/efeitos da radiação , Complexo de Proteína do Fotossistema II/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
7.
Int J Radiat Biol ; 96(4): 552-559, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31852388

RESUMO

Purpose: Light intensity is one of the important environmental factors that have strong influence on larviculture. Culture of fish at high intensity of light generates harmful radicals in the body that can compromise their health and production. The present study aims to evaluate the effect of various light intensities on the physiology of rohu Labeo rohita fry.Materials and Methods: Rohu fry (13.56 ± 0.4 mg) were exposed at five different light intensities: 0.17 ± 0.005 (Lc, control), 1.45 ± 0.23 (L1), 2.69 ± 0.47 (L2), 3.93 ± 0.72 (L3) and 5.06 ± 0.95 Wm-2 (L4). After 90 days of culture, rohu were harvested.Results and Conclusions: A 2-5% mortality of rohu was recorded in L3 and L4 treatments. The average weight and specific growth rate were significantly (p < .05) higher in Lc treatment compared to others. The light intensity and swimming activity of rohu showed direct relationship, whereas, light intensity showed inverse relation with nitric oxide synthase and reduced glutathione levels. Significantly (p < .05) higher glutathione S-transferase and glutathione peroxidase activies were found in rohu exposed at L4 treatment. Higher light intensities resulted in oxidative stress in the muscles of rohu. Thiobarbituric acid reactive substances, carbonyl protein and heat shock protein 70 were significantly (p < .05) higher in rohu exposed at L4 compared to other treatments. Exposure of rohu fry to intense light resulted into physiological stress and immunosupression.


Assuntos
Cyprinidae/fisiologia , Luz/efeitos adversos , Animais , Cyprinidae/crescimento & desenvolvimento , Glutationa/metabolismo , Proteínas de Choque Térmico HSP70/análise , Peroxidação de Lipídeos/efeitos da radiação , Estresse Oxidativo/efeitos da radiação , Estresse Fisiológico/efeitos da radiação , Natação
8.
Plant Physiol Biochem ; 147: 21-30, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31837557

RESUMO

Ultraviolet (UV)-B priming can boost the abiotic stress tolerance of plants by activating stress-responsive pathways. The main objective of the present study was to investigate the persistence of priming imprints and cross-tolerance inducing effects of UV-B priming in abiotic stress-sensitive rice (Oryza sativa L. 'Aiswarya') when subjected to various abiotic stressors (NaCl, PEG, and UV-B). The UV-B priming of rice seeds and seedlings effectively enhanced photosynthetic efficiency, antioxidant machinery activity, and antioxidative enzyme production, especially when seedlings were exposed to NaCl, followed by UV-B and PEG. The ability of UV-B priming to induce cross-tolerance against NaCl stress was substantiated by the greater antioxidant activity of the primed and NaCl-stressed seedlings. The greater performance and stress tolerance of the seedlings from UV-B-primed seeds were attributed to the carryover of priming imprints from seeds into the seedlings. Indeed, UV-B priming activated the antioxidant systems of the seedlings, even under non-stress conditions, and resulted in greater responses upon subsequent stress exposure, which suggested that preparedness for encountering imminent stress was attained by UV-B priming in a stress-sensitive rice.


Assuntos
Oryza , Plântula , Estresse Fisiológico , Raios Ultravioleta , Oryza/efeitos dos fármacos , Oryza/fisiologia , Oryza/efeitos da radiação , Oxirredutases/metabolismo , Fotossíntese , Plântula/enzimologia , Plântula/fisiologia , Plântula/efeitos da radiação , Estresse Fisiológico/efeitos da radiação
9.
Mol Cell Biochem ; 465(1-2): 141-153, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31823188

RESUMO

Ultraviolet radiations (UVR) are responsible for a wide variety of acute and chronic effects on the animal skin. However, the effect of UVR-induced oxidative stress and protection through paracrine factors on animal skin has received little attention. We previously demonstrated how heat stress-induced adaptation in Bos indicus melanocytes was dependent on the level of melanin and reduction of apoptosis. Therefore, in the present investigation, the survival mechanisms adopted by melanocytes under UV stress and the role of α-MSH in cell survival under in vitro conditions were studied. After the treatment of melanocyte cells with UVR (using Osram ultravitalux 300 W lamp), analysis of Gene expression using Real-Time PCR was done to study the adopted molecular pathways under stressful conditions. In addition, α-MSH was used to assess its modulating role in cell survival under stress. This study revealed the increase in the expression of genes related to melanogenesis, cell cycle, heat shock proteins, and apoptosis of the cells after UVR stress and demonstrated the role of paracrine factor (α-MSH) in elevating the protection response to stressful conditions like UVR stress by increasing the melanogenesis and decreasing the mitochondrial-mediated apoptosis. Based on the results of the present study, it can be stated that α-MSH can play a pivotal role in the protection of animal skin cells under stressful conditions in climate-changing scenario.


Assuntos
Apoptose/efeitos da radiação , Melaninas/metabolismo , Melanócitos/metabolismo , Estresse Fisiológico/efeitos da radiação , Raios Ultravioleta/efeitos adversos , alfa-MSH/metabolismo , Animais , Bovinos , Melanócitos/patologia , Pele/metabolismo , Pele/patologia
10.
Plant Biol (Stuttg) ; 22 Suppl 1: 143-152, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30597713

RESUMO

Plastid casein kinase 2 (CK2), which is a major Ser/Thr-specific enzyme in higher organisms, plays an essential role in plant development and diverse abiotic stresses. CKB1 is a regulatory subunit beta of CK2. To expand our understand of functions of the CKB1 gene in Arabidopsis thaliana, protein changes among wild-type (WT) and CKB1 gain- and loss-of-function mutants were compared. Proteins extracted from the CKB1 knockout mutant and overexpressing mutant were compared with Col-0 plants using 2D-PAGE. Proteins regulated by CKB1 were identified with matrix-assisted laser desorption ionisation time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF), and its transcript was verified by qRT-PCR. Bioinformatics analysis, including gene ontology and protein-protein interaction analysis, were employed. The results of mass spectra and bioinformatics analysis suggest that CKB1 may have functions in regulation of the ribosomal protein L10 (RPL10) family and is involved in ultraviolet-B (UV-B) response. Furthermore, qRT-PCR verification showed CKB1 expression was up-regulated by UV-B stress. The expression levels of five genes in the RPL10 family were reduced in the ckb1 T-DNA insertion mutants, whereas they increased in the CKB1 overexpressing mutants under both normal conditions and UV-B treatment. In conclusion, CKB1 has important functions in UV-B radiation stress. Our study implies that CKB1 positively regulates UV-B radiation stress signalling, possibly through modulating expression of the RPL10 family.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Caseína Quinase II , Regulação da Expressão Gênica de Plantas , Proteína Ribossômica L10 , Raios Ultravioleta , Arabidopsis/efeitos da radiação , Proteínas de Arabidopsis/genética , Caseína Quinase II/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Proteína Ribossômica L10/genética , Estresse Fisiológico/efeitos da radiação
11.
Biochem Biophys Res Commun ; 522(1): 177-183, 2020 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-31757427

RESUMO

UV RESISTANCE LOCUS 8 (UVR8) is a UV-B photoreceptor that regulates various aspects of plant photomorphogenesis. Physiological functions of UVR8 have been extensively investigated in Arabidopsis. However, functions of Tomato UVR8 (SlUVR8) are largely unknown. To analyze physiological functions of SlUVR8, we generated sluvr8 knock-out mutant lines with CRISPR-CAS9 gene editing approach. At seedling stage, SlUVR8 regulates hypocotyl elongation and anthocyanin accumulation under UV-B. Moreover, SlUVR8 regulates acclimation to low dose UV-B and promotes tolerance to elevated UV-B stress. These results revealed pivotal roles of SlUVR8 in the regulation of Tomato seedling development and UV-B stress tolerance. The manipulation of photoreceptor SlUVR8 may represent a powerful tool to improve Tomato plant performance in nature where high dose UV-B is present.


Assuntos
Lycopersicon esculentum/crescimento & desenvolvimento , Fotorreceptores de Plantas/metabolismo , Plântula/crescimento & desenvolvimento , Raios Ultravioleta/efeitos adversos , Antocianinas/metabolismo , Lycopersicon esculentum/efeitos da radiação , Plântula/efeitos da radiação , Estresse Fisiológico/efeitos da radiação
12.
Cell ; 179(5): 1098-1111.e23, 2019 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-31730852

RESUMO

We report a 100-million atom-scale model of an entire cell organelle, a photosynthetic chromatophore vesicle from a purple bacterium, that reveals the cascade of energy conversion steps culminating in the generation of ATP from sunlight. Molecular dynamics simulations of this vesicle elucidate how the integral membrane complexes influence local curvature to tune photoexcitation of pigments. Brownian dynamics of small molecules within the chromatophore probe the mechanisms of directional charge transport under various pH and salinity conditions. Reproducing phenotypic properties from atomistic details, a kinetic model evinces that low-light adaptations of the bacterium emerge as a spontaneous outcome of optimizing the balance between the chromatophore's structural integrity and robust energy conversion. Parallels are drawn with the more universal mitochondrial bioenergetic machinery, from whence molecular-scale insights into the mechanism of cellular aging are inferred. Together, our integrative method and spectroscopic experiments pave the way to first-principles modeling of whole living cells.


Assuntos
Células/metabolismo , Metabolismo Energético , Adaptação Fisiológica/efeitos da radiação , Trifosfato de Adenosina/metabolismo , Benzoquinonas/metabolismo , Membrana Celular/metabolismo , Membrana Celular/efeitos da radiação , Células/efeitos da radiação , Cromatóforos/metabolismo , Citocromos c2/metabolismo , Difusão , Transporte de Elétrons/efeitos da radiação , Metabolismo Energético/efeitos da radiação , Meio Ambiente , Ligação de Hidrogênio , Cinética , Luz , Simulação de Dinâmica Molecular , Fenótipo , Proteínas/metabolismo , Rhodobacter sphaeroides/fisiologia , Rhodobacter sphaeroides/efeitos da radiação , Eletricidade Estática , Estresse Fisiológico/efeitos da radiação , Temperatura
13.
Nucleic Acids Res ; 47(21): 11403-11417, 2019 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-31598697

RESUMO

Exposure to harmful conditions such as radiation and desiccation induce oxidative stress and DNA damage. In radiation-resistant Deinococcus bacteria, the radiation/desiccation response is controlled by two proteins: the XRE family transcriptional repressor DdrO and the COG2856 metalloprotease IrrE. The latter cleaves and inactivates DdrO. Here, we report the biochemical characterization and crystal structure of DdrO, which is the first structure of a XRE protein targeted by a COG2856 protein. DdrO is composed of two domains that fold independently and are separated by a flexible linker. The N-terminal domain corresponds to the DNA-binding domain. The C-terminal domain, containing three alpha helices arranged in a novel fold, is required for DdrO dimerization. Cleavage by IrrE occurs in the loop between the last two helices of DdrO and abolishes dimerization and DNA binding. The cleavage site is hidden in the DdrO dimer structure, indicating that IrrE cleaves DdrO monomers or that the interaction with IrrE induces a structural change rendering accessible the cleavage site. Predicted COG2856/XRE regulatory protein pairs are found in many bacteria, and available data suggest two different molecular mechanisms for stress-induced gene expression: COG2856 protein-mediated cleavage or inhibition of oligomerization without cleavage of the XRE repressor.


Assuntos
Deinococcus , Proteínas Repressoras/química , Estresse Fisiológico/genética , Estresse Fisiológico/efeitos da radiação , Fatores de Transcrição/química , Sequência de Aminoácidos , Cristalografia por Raios X , Dano ao DNA , Deinococcus/enzimologia , Deinococcus/genética , Deinococcus/metabolismo , Deinococcus/efeitos da radiação , Regulação Bacteriana da Expressão Gênica/efeitos da radiação , Metaloproteases/química , Metaloproteases/genética , Metaloproteases/metabolismo , Modelos Moleculares , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Proteínas Repressoras/genética , Fatores de Transcrição/genética
14.
Plant Physiol ; 181(4): 1480-1497, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31604811

RESUMO

Degradation of periplasmic proteins (Deg)/high temperature requirement A (HtrA) proteases are ATP-independent Ser endopeptidases that perform key aspects of protein quality control in all domains of life. Here, we characterized Chlamydomonas reinhardtii DEG1C, which together with DEG1A and DEG1B is orthologous to Arabidopsis (Arabidopsis thaliana) Deg1 in the thylakoid lumen. We show that DEG1C is localized to the stroma and the periphery of thylakoid membranes. Purified DEG1C exhibited high proteolytic activity against unfolded model substrates and its activity increased with temperature and pH. DEG1C forms monomers, trimers, and hexamers that are in dynamic equilibrium. DEG1C protein levels increased upon nitrogen, sulfur, and phosphorus starvation; under heat, oxidative, and high light stress; and when Sec-mediated protein translocation was impaired. DEG1C depletion was not associated with any obvious aberrant phenotypes under nonstress conditions, high light exposure, or heat stress. However, quantitative shotgun proteomics revealed differences in the abundance of 307 proteins between a deg1c knock-out mutant and the wild type under nonstress conditions. Among the 115 upregulated proteins are PSII biogenesis factors, FtsH proteases, and proteins normally involved in high light responses, including the carbon dioxide concentrating mechanism, photorespiration, antioxidant defense, and photoprotection. We propose that the lack of DEG1C activity leads to a physiological state of the cells resembling that induced by high light intensities and therefore triggers high light protection responses.


Assuntos
Aclimatação/efeitos da radiação , Chlamydomonas/genética , Chlamydomonas/efeitos da radiação , Luz , Mutação/genética , Proteínas de Plantas/genética , Acetatos/metabolismo , Concentração de Íons de Hidrogênio , Modelos Biológicos , Fenótipo , Fotossíntese/efeitos da radiação , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Dobramento de Proteína/efeitos da radiação , Multimerização Proteica , Proteólise/efeitos da radiação , Estresse Fisiológico/efeitos da radiação , Frações Subcelulares/metabolismo , Frações Subcelulares/efeitos da radiação , Especificidade por Substrato/efeitos da radiação , Temperatura , Tilacoides/metabolismo , Tilacoides/efeitos da radiação
15.
Plant Signal Behav ; 14(10): e1649568, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31397633

RESUMO

High light and high temperature (HLHT) stress induces the production of damaging reactive oxygen species (ROS) in many plants. Recently, we described a HLHT-sensitive rice (Oryza sativa) mutant, local lesions (ls1), that exhibits local lesions under HLHT, due to DNA damage and excess ROS accumulation. Here, we determined that an HLHT treatment induced the local lesion phenotype in ls1 within 6 h. Corroborating this result, we found that transient HLHT treatment influenced the expression of many genes in the ls1 mutant, while affecting the growth and development of young leaves.


Assuntos
Genes de Plantas , Temperatura Alta , Luz , Mutação/genética , Oryza/genética , Oryza/fisiologia , Estresse Fisiológico/efeitos da radiação , Transcriptoma/genética , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Ontologia Genética , Oryza/efeitos da radiação , Fenótipo , Folhas de Planta/fisiologia , Folhas de Planta/efeitos da radiação , Estresse Fisiológico/genética , Transcriptoma/efeitos da radiação
16.
Ultrasound Med Biol ; 45(11): 3005-3017, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31421866

RESUMO

Eukaryotic cells can survive sonoporation and repair their plasma membrane wounds. However, it is not clear how the repaired plasma membranes will differ from the intact ones. To answer this question, we used high-resolution confocal microscopy and scanning electron microscopy to study plasma membrane lipid alterations induced by sonoporation. First, we found that the wound-induced increase in membrane lipid content was not limited to the sonoporation sites. The degree of lipid increase was dependent on pore distance, calcium influx and pore size. Second, we observed interesting lipid striation patterns on the sonoporated plasma membranes. This patterning effect was reversible in the cell subjected to small-scale sonoporation and could be recognized using digital image orientation analysis. Third, we showed that actin stress fibers underneath the plasma membrane hindered the addition and the protrusion of lipids to produce the patterning effect. Our findings demonstrated that the sonoporated and repaired plasma membranes have distinct lipid distribution characteristics.


Assuntos
Membrana Celular/efeitos da radiação , Fibroblastos/efeitos da radiação , Ondas de Choque de Alta Energia , Lipídeos/análise , Sonicação , Membrana Celular/ultraestrutura , Células Cultivadas , Fibroblastos/ultraestrutura , Humanos , Microbolhas , Microscopia Confocal , Microscopia Eletrônica de Varredura , Estresse Fisiológico/efeitos da radiação
17.
Plant J ; 100(5): 1007-1021, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31410901

RESUMO

DNA damage responses are crucial for plant growth under genotoxic stress. Accumulating evidence indicates that DNA damage responses differ between plant cell types. Here, quantitative shotgun phosphoproteomics provided high-throughput analysis of the DNA damage response network in callus cells. MS analysis revealed a wide network of highly dynamic changes in the phosphoprotein profile of genotoxin-treated cells, largely mediated by the ATAXIA TELANGIECTASIA MUTATED (ATM) protein kinase, representing candidate factors that modulate plant growth, development and DNA repair. A C-terminal dual serine target motif unique to H2AX in the plant lineage showed 171-fold phosphorylation that was absent in atm mutant lines. The physiological significance of post-translational DNA damage signalling to plant growth and survival was demonstrated using reverse genetics and complementation studies of h2ax mutants, establishing the functional role of ATM-mediated histone modification in plant growth under genotoxic stress. Our findings demonstrate the complexity and functional significance of post-translational DNA damage signalling responses in plants and establish the requirement of H2AX phosphorylation for plant survival under genotoxic stress.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Reparo do DNA , Histonas/metabolismo , Proteoma/metabolismo , Sementes/crescimento & desenvolvimento , Estresse Fisiológico , Transportadores de Cassetes de Ligação de ATP/genética , Envelhecimento/metabolismo , Envelhecimento/fisiologia , Envelhecimento/efeitos da radiação , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/efeitos da radiação , Proteínas de Arabidopsis/genética , Células Cultivadas , Dano ao DNA/genética , Dano ao DNA/efeitos da radiação , Reparo do DNA/genética , Reparo do DNA/efeitos da radiação , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Ontologia Genética , Germinação/genética , Germinação/efeitos da radiação , Histonas/química , Espectrometria de Massas , Fosforilação , Proteoma/genética , Proteoma/efeitos da radiação , Sementes/metabolismo , Sementes/fisiologia , Sementes/efeitos da radiação , Serina/química , Serina/metabolismo , Transdução de Sinais/efeitos da radiação , Estresse Fisiológico/genética , Estresse Fisiológico/efeitos da radiação , Raios X
18.
Int J Biol Macromol ; 139: 1212-1223, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31415851

RESUMO

Chitosan, being one of the most promising biological macromolecules, has an immense scope in agriculture to boost crop growth and defense responses. In this study, chitosan was exposed to gamma rays in order to obtain a low molecular weight derivative. Viscometric characterization showed a sharp decrease in molecular weight and FTIR based analysis confirmed retention of structural integrity of the polymer upon gamma irradiation. Assessments of various physiological and biochemical attributes were carried out on sugarcane plantlets that were subjected to progressive water deficit stress. The irradiated chitosan was found to differentially ameliorate water deficit stress tolerance against that of normal chitosan through positive modulation of various gas exchange parameters alongside significant improvement in relative tissue water content, SOD activity, soluble sugars and adenine energetics. Furthermore, application of irradiated chitosan significantly reduced cell membrane damage, lipid peroxidation, H2O2 and free-proline accumulations. This is the first report on the use of gamma irradiated chitosan to alleviate water deficit stress tolerance in sugarcane. Overall comparative assessments showed that differential plant responses were triggered upon foliar application of normal and gamma irradiated chitosan in sugarcane plants grown under water deficit stress conditions.


Assuntos
Secas , Raios gama , Folhas de Planta/efeitos da radiação , Saccharum/fisiologia , Saccharum/efeitos da radiação , Estresse Fisiológico/efeitos da radiação , Metabolismo Energético/efeitos da radiação , Peróxido de Hidrogênio/metabolismo , Peroxidação de Lipídeos/efeitos da radiação , Osmose/efeitos da radiação , Fotossíntese/efeitos da radiação , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Prolina/metabolismo , Saccharum/metabolismo , Superóxido Dismutase/metabolismo , Água/metabolismo
19.
J Strength Cond Res ; 33(10): 2608-2615, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31361730

RESUMO

Otani, H, Goto, T, Goto, H, Hosokawa, Y, and Shirato, M. Solar radiation exposure has diurnal effects on thermoregulatory responses during high-intensity exercise in the heat outdoors. J Strength Cond Res 33(10): 2608-2615, 2019-This study investigated the diurnal effects of variations in solar radiation associated with changing solar elevation angle on thermoregulatory responses during high-intensity exercise in the heat outdoors. Ten male high school soccer players completed two 2-hour soccer training sessions under a clear sky in the heat of summer. These sessions were commenced at 0900 hours (AM) and 1600 hours (PM) on separate days. Solar radiation and elevation angle were higher in AM (820-1,070 W·m and 45-69°) than PM (620-110 W·m and 34-10°: both p < 0.001). Neither ambient temperature (AM 29-32° C; PM 31-31° C) nor wet-bulb globe temperature was different between trials. Although mean skin temperature was not different between trials, infrared tympanic temperature was higher at the end of exercise in AM than PM (p < 0.001). Heart rate (p < 0.01) and body heat gain from the sun (p < 0.001) were greater during exercise in AM than PM. Dry heat loss was smaller, but evaporative heat loss was greater in AM than PM (both p < 0.001). Thermal sensation and rating of perceived exertion were similar between trials, but GPS measurements showed a less total distance and distance covered by walking, jogging, and running in AM than PM (p < 0.01). This study demonstrates a greater thermoregulatory strain in AM than PM during 2-hour high-intensity soccer training in the heat under a clear sky. This observation is accompanied by a progressive increase in environmental heat stress with rising solar radiation and elevation angle in AM and a greater body heat gain from the sun in AM compared with PM.


Assuntos
Regulação da Temperatura Corporal/efeitos da radiação , Exposição à Radiação , Futebol/fisiologia , Estresse Fisiológico/efeitos da radiação , Luz Solar , Adolescente , Temperatura Corporal , Regulação da Temperatura Corporal/fisiologia , Ritmo Circadiano/efeitos da radiação , Exercício Físico/fisiologia , Frequência Cardíaca , Temperatura Alta , Humanos , Masculino , Estresse Fisiológico/fisiologia , Sensação Térmica , Perda Insensível de Água
20.
Int J Mol Sci ; 20(15)2019 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-31357484

RESUMO

Sphingosine 1-phosphate (S1P) is a potent lipid mediator that modulates inflammation and angiogenesis. In this study, we investigated the possible involvement of S1P in the pathology of light-induced retinal degeneration in vivo and in vitro. The intracellular S1P and sphingosine kinase (SphK) activity in a photoreceptor cell line (661W cells) was significantly increased by exposure to light. The enhancement of SphK1 expression was dependent on illumination, and all-trans-retinal significantly promoted SphK1 expression. S1P treatment reduced protein kinase B (Akt) phosphorylation and increased the protein expression of cleaved caspase-3, and induced photoreceptor cell apoptosis. In vivo, light exposure enhanced the expression of SphK1 in the outer segments of photoreceptors. Intravitreal injection of a SphK inhibitor significantly suppressed the thinning of the outer nuclear layer and ameliorated the attenuation of the amplitudes of a-waves and b-waves of electroretinograms during light-induced retinal degeneration. These findings imply that light exposure induces the synthesis of S1P in photoreceptors by upregulating SphK1, which is facilitated by all-trans-retinal, causing retinal degeneration. Inhibition of this enhancement may be a therapeutic target of outer retinal degeneration, including age-related macular degeneration.


Assuntos
Luz , Lisofosfolipídeos/biossíntese , Células Fotorreceptoras/metabolismo , Células Fotorreceptoras/efeitos da radiação , Degeneração Retiniana/etiologia , Degeneração Retiniana/metabolismo , Esfingosina/análogos & derivados , Estresse Fisiológico/efeitos da radiação , Animais , Apoptose , Linhagem Celular , Modelos Animais de Doenças , Suscetibilidade a Doenças , Eletrorretinografia , Humanos , Luz/efeitos adversos , Degeneração Macular/etiologia , Degeneração Macular/metabolismo , Degeneração Macular/patologia , Camundongos , Fosfotransferases (Aceptor do Grupo Álcool)/antagonistas & inibidores , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Células Fotorreceptoras/patologia , Retina/metabolismo , Retina/patologia , Retina/efeitos da radiação , Degeneração Retiniana/diagnóstico por imagem , Degeneração Retiniana/patologia , Esfingosina/biossíntese , Tomografia de Coerência Óptica
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