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1.
Chem Res Toxicol ; 37(7): 1187-1198, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38837948

RESUMEN

Hydroquinone(HQ) is a widely used industrial raw material and is a topical lightening product found in over-the-counter products. However, inappropriate exposure to HQ can pose certain health hazards. This study aims to explore the mechanisms of DNA damage and cell apoptosis caused by HQ, with a focus on whether HQ activates the nuclear factor-κB (NF-κB) pathway to participate in this process and to investigate the correlation between the NF-κB pathway activation and poly(ADP-ribose) polymerase 1(PARP1). Through various experimental techniques, such as DNA damage detection, cell apoptosis assessment, cell survival rate analysis, immunofluorescence, and nuclear-cytoplasmic separation, the cytotoxic effects of HQ were verified, and the activation of the NF-κB pathway was observed. Simultaneously, the relationship between the NF-κB pathway and PARP1 was verified by shRNA interference experiments. The results showed that HQ could significantly activate the NF-κB pathway, leading to a decreased cell survival rate, increased DNA damage, and cell apoptosis. Inhibiting the NF-κB pathway could significantly reduce HQ-induced DNA damage and cell apoptosis and restore cell proliferation and survival rate. shRNA interference experiments further indicated that the activation of the NF-κB pathway was regulated by PARP1. This study confirmed the important role of the NF-κB pathway in HQ-induced DNA damage and cell apoptosis and revealed that the activation of the NF-κB pathway was mediated by PARP1. This research provides important clues for a deeper understanding of the toxic mechanism of HQ.


Asunto(s)
Apoptosis , Supervivencia Celular , Daño del ADN , Hidroquinonas , FN-kappa B , Poli(ADP-Ribosa) Polimerasa-1 , Apoptosis/efectos de los fármacos , Poli(ADP-Ribosa) Polimerasa-1/metabolismo , Poli(ADP-Ribosa) Polimerasa-1/antagonistas & inhibidores , Hidroquinonas/farmacología , Humanos , FN-kappa B/metabolismo , Daño del ADN/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Línea Celular , Transducción de Señal/efectos de los fármacos , Relación Dosis-Respuesta a Droga
2.
Ecotoxicol Environ Saf ; 276: 116295, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38581908

RESUMEN

Leukemia caused by environmental chemical pollutants has attracted great attention, the malignant leukemic transformation model of TK6 cells induced by hydroquinone (HQ) has been previously found in our team. However, the type of leukemia corresponding to this malignant transformed cell line model needs further study and interpretation. Furthermore, the molecular mechanism of malignant proliferation of leukemic cells induced by HQ remains unclear. This study is the first to reveal the expression of aberrant genes in leukemic cells of HQ-induced malignant transformation, which may correspond to chronic lymphocytic leukemia (CLL). The expression of Linc01588, a long non-coding RNA (lncRNA), was significantly up-regulated in CLL patients and leukemic cell line model which previously described. After gain-of-function assays and loss-of-function assays, feeble cell viability, severe apoptotic phenotype and the increased secretion of TNF-α were easily observed in malignant leukemic TK6 cells with Linc01588 deletion after HQ intervention. The tumors derived from malignant TK6 cells with Linc01588 deletion inoculated subcutaneously in nude mice were smaller than controls. In CLL and its cell line model, the expression of Linc01588 and miR-9-5p, miR-9-5p and SIRT1 were negative correlation respectively in CLL and cell line model, while the expression of Linc01588 and SIRT1 were positive correlation. The dual-luciferase reporter assay showed that Linc01588 & miR-9-5p, miR-9-5p & SIRT1 could bind directly, respectively. Furthermore, knockdown of miR-9-5p successfully rescued the severe apoptotic phenotype and the increased secretion of TNF-α caused by the Linc01588 deletion, the deletion of Linc01588 in human CLL cell line MEC-2 could also inhibit malignant biological characteristics, and the phenotype caused by the deletion of Linc01588 could also be rescued after overexpression of SIRT1. Moreover, the regulation of SIRT1 expression in HQ19 cells by Linc01588 and miR-9-5 P may be related to the Akt/NF-κB pathway. In brief, Linc01588 deletion inhibits the malignant biological characteristics of HQ-induced leukemic cells via miR-9-5p/SIRT1, and it is a novel and hopeful clue for the clinical targeted therapy of CLL.


Asunto(s)
Hidroquinonas , Leucemia Linfocítica Crónica de Células B , Ratones Desnudos , MicroARNs , ARN Largo no Codificante , Sirtuina 1 , Sirtuina 1/genética , Sirtuina 1/metabolismo , MicroARNs/genética , Hidroquinonas/toxicidad , Humanos , ARN Largo no Codificante/genética , Animales , Línea Celular Tumoral , Leucemia Linfocítica Crónica de Células B/genética , Leucemia Linfocítica Crónica de Células B/patología , Ratones , Apoptosis/efectos de los fármacos , Femenino , Masculino , Proliferación Celular/efectos de los fármacos
3.
Appl Environ Microbiol ; 88(7): e0221521, 2022 04 12.
Artículo en Inglés | MEDLINE | ID: mdl-35311507

RESUMEN

Rhodotorula mucilaginosa shows adaption to a broad range of Pb2+ stress. In this study, three key pathways, i.e., glycolysis (EMP), the tricarboxylic acid (TCA) cycle, and oxidative phosphorylation (OXPHOS), were investigated under 0-2,500 mg · L-1 Pb stress, primarily based on biochemical analysis and RNA sequencing. R. mucilaginosa cells showed similar metabolic response to low/medium (500/1000 mg · L-1) Pb2+ stress. High (2,500 mg · L-1) Pb2+ stress exerted severe cytotoxicity to R. mucilaginosa. The downregulation of HK under low-medium Pb2+ suggested a correlation with the low hexokinase enzymatic activity in vivo. However, IDH3, regulating a key step of circulation in TCA, was upregulated to promote ATP feedstock for downstream OXPHOS. Then, through activation of complex I & IV in the electron transport chain (ETC) and ATP synthase, ATP production was finally enhanced. This mechanism enabled fungal cells to compensate for ATP consumption under low-medium Pb2+ toxicity. Hence, R. mucilaginosa tolerance to such a broad range of Pb2+ concentrations can be attributed to energy adaption. In contrast, high Pb2+ stress caused ATP deficiency. Then, the subsequent degradation of intracellular defense systems further intensified Pb toxicity. This study correlated responses of EMP, TCA, and OXPHOS pathways in R. mucilaginosa under Pb stress, hence providing new insights into the fungal resistance to heavy metal stress. IMPORTANCE Glycolysis (EMP), the tricarboxylic acid (TCA) cycle, and oxidative phosphorylation (OXPHOS) are critical metabolism pathways for microorganisms to obtain energy during the resistance to heavy metal (HM) stress. However, these pathways at the genetic level have not been elucidated to evaluate their cytoprotective functions for Rhodotorula mucilaginosa under Pb stress. In this study, we investigated these three pathways based on biochemical analysis and RNA sequencing. Under low-medium (500-1,000 mg · L-1) Pb2+ stress, ATP production was stimulated mainly due to the upregulation of genes associated with the TCA cycle and the electron transport chain (ETC). Such an energy compensatory mechanism could allow R. mucilaginosa acclimation to a broad range of Pb2+ concentrations (up to 1000 mg · L-1). In contrast, high (2500 mg · L-1) Pb2+ stress exerted its excessive toxicity by provoking ATP deficiency and damage to intracellular resistance systems. This study provided new insights into R. mucilaginosa resistance to HM stress from the perspective of metabolism.


Asunto(s)
Plomo , Metales Pesados , Adenosina Trifosfato , Ciclo del Ácido Cítrico , Perfilación de la Expresión Génica , Plomo/toxicidad , Rhodotorula , Ácidos Tricarboxílicos
4.
Plant Physiol ; 187(4): 2563-2576, 2021 12 04.
Artículo en Inglés | MEDLINE | ID: mdl-34618079

RESUMEN

Brassinosteroids (BRs) regulate various agronomic traits such as plant height, leaf angle, and grain size in rice (Oryza sativa L.); thus, BR signaling components are promising targets for molecular rational design. However, genetic materials for BR-signaling genes or family members remain limited in rice. Here, by genome editing using clustered regularly interspaced short palindromic repeats (CRSPR)/Cas9 tools, we generated a panel of single, double, triple, or quadruple mutants within three BR signaling gene families, including GSK3/SHAGGY-LIKE KINASE1 (GSK1)-GSK4, BRASSINAZOLE-RESISTANT1 (OsBZR1)-OsBZR4, and protein phosphatases with kelch-like (PPKL)1-PPKL3, under the same background (Zhonghua11, japonica). The high-order mutants were produced by either simultaneously targeting multiple sites on different genes of one family (GSKs and PPKLs) or targeting the overlapping sequences of family members (OsBZRs). The mutants exhibited a diversity of plant height, leaf angle, and grain morphology. Comparison analysis of the phenotypes together with BR sensitivity tests suggested the existence of functional redundancy, differentiation, or dominancy among the members within each family. In addition, we generated a set of transgenic plants overexpressing GSK2, OsBZR1/2, and PPKL2, respectively, in wild-type or activated forms with fusion of different tags, and also verified the protein response to BR application. Collectively, these plants greatly enriched the diversity of important agronomic traits in rice. We propose that editing of BR-related family genes could be a feasible approach for screening of desired plants to meet different requirements. Release of these materials as well as the related information also provides valuable resources for further BR research and utilization.


Asunto(s)
Brasinoesteroides/metabolismo , Edición Génica , Genoma de Planta , Oryza/genética , Proteínas de Plantas/metabolismo , Transducción de Señal
5.
Plant Cell Environ ; 45(5): 1520-1536, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35150141

RESUMEN

Nitrogen (N) is an essential macronutrient for crop growth and yield. Improving the N use efficiency (NUE) of crops is important to agriculture. However, the molecular mechanisms underlying NUE regulation remain largely elusive. Here we report that the OsNLP3 (NIN-like protein 3) regulates NUE and grain yield in rice under N sufficient conditions. OsNLP3 transcript level is significantly induced by N starvation and its protein nucleocytosolic shuttling is specifically regulated by nitrate. Loss-of-function of OsNLP3 reduces plant growth, grain yield, and NUE under sufficient nitrate conditions, whereas under low nitrate or different ammonium conditions, osnlp3 mutants show no clear difference from the wild type. Importantly, under sufficient N conditions in the field, OsNLP3 overexpression lines display improved grain yield and NUE compared with the wild type. OsNLP3 orchestrates the expression of multiple N uptake and assimilation genes by directly binding to the nitrate-responsive cis-elements in their promoters. Overall, our study demonstrates that OsNLP3, together with OsNLP1 and OsNLP4, plays overlapping and differential roles in N acquisition and NUE, and modulates NUE and the grain yield increase promoted by N fertilizer. Therefore, OsNLP3 is a promising candidate gene for the genetic improvement of grain yield and NUE in rice.


Asunto(s)
Oryza , Grano Comestible/metabolismo , Fertilizantes , Nitratos/metabolismo , Nitrógeno/metabolismo , Oryza/genética , Oryza/metabolismo
6.
J Integr Plant Biol ; 64(8): 1614-1630, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35766344

RESUMEN

Japonica/geng and indica/xian are two major rice (Oryza sativa) subspecies with multiple divergent traits, but how these traits are related and interact within each subspecies remains elusive. Brassinosteroids (BRs) are a class of steroid phytohormones that modulate many important agronomic traits in rice. Here, using different physiological assays, we revealed that japonica rice exhibits an overall lower BR sensitivity than indica. Extensive screening of BR signaling genes led to the identification of a set of genes distributed throughout the primary BR signaling pathway with divergent polymorphisms. Among these, we demonstrate that the C38/T variant in BR Signaling Kinase2 (OsBSK2), causing the amino acid change P13L, plays a central role in mediating differential BR signaling in japonica and indica rice. OsBSK2L13 in indica plays a greater role in BR signaling than OsBSK2P13 in japonica by affecting the auto-binding and protein accumulation of OsBSK2. Finally, we determined that OsBSK2 is involved in a number of divergent traits in japonica relative to indica rice, including grain shape, tiller number, cold adaptation, and nitrogen-use efficiency. Our study suggests that the natural variation in OsBSK2 plays a key role in the divergence of BR signaling, which underlies multiple divergent traits between japonica and indica.


Asunto(s)
Oryza , Brasinoesteroides/metabolismo , Oryza/metabolismo , Fenotipo , Reguladores del Crecimiento de las Plantas/metabolismo , Proteínas de Plantas/metabolismo
7.
Plant Biotechnol J ; 19(3): 448-461, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-32876985

RESUMEN

Nitrogen (N) is one of the key essential macronutrients that affects rice growth and yield. Inorganic N fertilizers are excessively used to boost yield and generate serious collateral environmental pollution. Therefore, improving crop N use efficiency (NUE) is highly desirable and has been a major endeavour in crop improvement. However, only a few regulators have been identified that can be used to improve NUE in rice to date. Here we show that the rice NIN-like protein 4 (OsNLP4) significantly improves the rice NUE and yield. Field trials consistently showed that loss-of-OsNLP4 dramatically reduced yield and NUE compared with wild type under different N regimes. In contrast, the OsNLP4 overexpression lines remarkably increased yield by 30% and NUE by 47% under moderate N level compared with wild type. Transcriptomic analyses revealed that OsNLP4 orchestrates the expression of a majority of known N uptake, assimilation and signalling genes by directly binding to the nitrate-responsive cis-element in their promoters to regulate their expression. Moreover, overexpression of OsNLP4 can recover the phenotype of Arabidopsis nlp7 mutant and enhance its biomass. Our results demonstrate that OsNLP4 plays a pivotal role in rice NUE and sheds light on crop NUE improvement.


Asunto(s)
Arabidopsis , Oryza , Fertilizantes , Nitratos , Nitrógeno , Oryza/genética
8.
Environ Microbiol ; 22(4): 1507-1516, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31215728

RESUMEN

Successful application of microorganisms to heavy metal remediation depends on their resistance to toxic metals. This study contrasted the differences of tolerant mechanisms between Pb2+ and Cd2+ in Enterobacter sp. Microbial respiration and production of formic acid showed that Enterobacter sp. had a higher tolerant concentration of Pb (>1000 mg l-1 ) than Cd (about 200 mg l-1 ). Additionally, SEM confirmed that most of Pb and Cd nanoparticles (NPs) were adsorbed onto cell membrane. The Cd stress, even at low concentration (50 mg l-1 ), significantly enlarged the sizes of cells. The cellular size raised from 0.4 × 1.0 to 0.9 × 1.6 µm on average, inducing a platelet-like shape. In contrast, Pb cations did not stimulate such enlargement even up to 1000 mg l-1 . Moreover, Cd NPs were adsorbed homogeneously by almost all the bacterial cells under TEM. However, only a few cells work as 'hot spots' on the sorption of Pb NPs. The heterogeneous sorption might result from a 'self-sacrifice' mechanism, i.e., some cells at a special life stage contributed mostly to Pb sorption. This mechanism, together with the lower mobility of Pb cations, caused higher microbial tolerance and removal efficiency towards Pb2+ . This study sheds evident contrasts of bacterial resistance to the two most common heavy metals.


Asunto(s)
Cadmio/toxicidad , Enterobacter/efectos de los fármacos , Plomo/toxicidad , Nanopartículas del Metal/toxicidad , Adsorción , Cadmio/química , Membrana Celular/química , Tamaño de la Célula/efectos de los fármacos , Enterobacter/química , Enterobacter/metabolismo , Enterobacter/ultraestructura , Formiatos/metabolismo , Plomo/química , Nanopartículas del Metal/química , Microscopía Electrónica de Transmisión , Estrés Fisiológico
9.
Proc Biol Sci ; 287(1925): 20200403, 2020 04 29.
Artículo en Inglés | MEDLINE | ID: mdl-32290797

RESUMEN

Even though bacteria are important in determining plant growth and health via volatile organic compounds (VOCs), it is unclear how these beneficial effects emerge in multi-species microbiomes. Here we studied this using a model plant-bacteria system, where we manipulated bacterial community richness and composition and determined the subsequent effects on VOC production and VOC-mediated pathogen suppression and plant growth-promotion. We assembled VOC-producing bacterial communities in different richness levels ranging from one to 12 strains using three soil-dwelling bacterial genera (Bacillus, Paenibacillus and Pseudomonas) and investigated how the composition and richness of bacterial community affect the production and functioning of VOCs. We found that VOC production correlated positively with pathogen suppression and plant growth promotion and that all bacteria produced a diverse set of VOCs. However, while pathogen suppression was maximized at intermediate community richness levels when the relative amount and the number of VOCs were the highest, plant growth promotion was maximized at low richness levels and was only affected by the relative amount of plant growth-promoting VOCs. The contrasting effects of richness could be explained by differences in the amount and number of produced VOCs and by opposing effects of community productivity and evenness on pathogen suppression and plant-growth promotion along the richness gradient. Together, these results suggest that the number of interacting bacterial species and the structure of the rhizosphere microbiome drive the balance between VOC-mediated microbe-pathogen and microbe-plant interactions potentially affecting plant disease outcomes in natural and agricultural ecosystems.


Asunto(s)
Microbiota , Plantas/microbiología , Rizosfera , Microbiología del Suelo , Desarrollo de la Planta
10.
Plant Physiol ; 181(3): 1295-1313, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31431512

RESUMEN

Most characterized plant resistance proteins belong to the nucleotide-binding domain and Leu-rich repeat-containing (NLR) family. NLRs are present in an auto-inhibited state in the absence of specific pathogens, while gain-of-function mutations in NLRs usually cause autoimmunity. Here, we show that a gain-of-function mutation, weaker defense (wed), which caused a Phe-to-Leu substitution in the nucleotide-binding domain of a typical NLR in rice (Oryza sativa), led to enhanced susceptibility to Xanthomonas oryzae pv. Oryzae The unexpected accumulation of salicylic acid (SA), along with downregulation of NONEXPRESSOR OF PR1 (NPR1), in wed indicates the potential presence of a feedback regulation loop of SA biosynthesis in rice. Epistasis analyses illustrated that SA accumulation and the NLR-associated components RAR1, OsRac1, and PhyB are dispensable for the wed phenotypes. Intriguingly, besides pattern-triggered immunity, effector-triggered immunity conferred by different resistance proteins, including Xa3/Xa26, Xa4, and Xa21, was also disturbed by wed to a certain extent, indicating the existence of shared regulatory mechanisms for various defense systems. The identification of wed therefore provides a unique system for genetic dissection of shared immune signaling pathways activated by different types of immune receptors.


Asunto(s)
Oryza/metabolismo , Oryza/microbiología , Proteínas de Plantas/metabolismo , Proteínas/metabolismo , Regulación de la Expresión Génica de las Plantas/genética , Proteínas Repetidas Ricas en Leucina , Mutación/genética , Oryza/genética , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/genética , Proteínas/genética , Xanthomonas/patogenicidad
11.
Ecotoxicol Environ Saf ; 194: 110441, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32155484

RESUMEN

Vesicles (Ves) within fungal cells are the critical linkage between intracellular and extracellular systems. This study explored the application of Pb2+ to probe the physiology of intracellular Ves in Rhodotorula mucilaginosa (Rho). At low Pb2+ levels (0-500 mg/L), there was no evident change in the content of extracellular polymeric substances (EPS) or microbial activity. At medium-high levels (1000-2000 mg/L), the sizes of Ves within the Rho cells were significantly enlarged, with abundant lead nano-particles (Pb NPs) formed either on the cell surface or interior, whereas the EPS content and bioactivity were still stable. At a high level (2500 mg/L), the Rho cells were severely deformed, with cell counts reduced by more than 99%. However, the EPS contents and the respiration rate of the surviving cells dramatically increased to the maximum values (i.e., 1785 mg/1010 cells and 37 mg C 10-10 cells h-1, respectively). The Ves surface adsorbed Pb cations with higher density, compared with the cell membrane. Moreover, fusion of some Ves to the membrane (functioning in transport) was observed under transmission electron microscope (TEM). Three pathways of detoxification via intracellular Ves were finally proposed, i.e., Ve-mediated transport (from intracellular to extracellular) of EPS components, absorption of Pb NPs on the Ve surface, and accumulation of Pb NPs within Ves. This study sheds light on the possibility of exploring microbial physiology via Pb2+ cations.


Asunto(s)
Sustancias Peligrosas/toxicidad , Plomo/toxicidad , Rhodotorula/fisiología , Adsorción , Cationes , Pruebas de Toxicidad
12.
Environ Microbiol ; 21(1): 471-479, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30421848

RESUMEN

Environmental microorganisms have been widely applied in heavy metal remediation. This study explored the mechanisms of lead tolerance of two typical filamentous fungi, Aspergillus niger and Penicillium oxalicum. It is shown that the mechanisms of reducing Pb toxicity by these two fungi have three major pathways. The secreted oxalic acid can react with Pb (II) to form insoluble Pb minerals, primarily lead oxalate. Then, the enhanced biosorption via forming new border of cell wall prevents the transportation of Pb (II) into hypha. In addition, the fungal activity could be maintained even at high Pb concentration due to the intracellular accumulation. It was confirmed that A. niger has the higher Pb tolerance (up to 1500 mg l-1 Pb level) compared with P. oxalicum (up to 1000 mg l-1 ). Meanwhile, Pb levels below 1000 mg l-1 partially stimulate the bioactivity of A. niger, which was confirmed by its elevated respiration (from 53 to 63 mg C l-1 medium h-1 ). This subsequently enhanced microbial functions of A. niger to resist Pb toxicity. A better understanding of Pb tolerance of these two fungi sheds a bright future of applying them to remediate lead-contaminated environments.


Asunto(s)
Aspergillus niger/metabolismo , Biodegradación Ambiental , Plomo/toxicidad , Ácido Oxálico/metabolismo , Penicillium/metabolismo , Aspergillus niger/efectos de los fármacos , Minerales/metabolismo , Oxalatos/metabolismo , Penicillium/efectos de los fármacos
13.
Nanotechnology ; 30(4): 045602, 2019 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-30479314

RESUMEN

Recently, there has been strong interest in flexible and wearable electronics to meet the technological demands of modern society. Environmentally-friendly and scalable electronic textiles is a key area that is still significantly underdeveloped. Here, we describe a novel strain sensor composed of aligned cellulose acetate (CA) nanofibers with belt-like morphology and a reduced graphene oxide (RGO) layer. The unique spatial alignment, microstructure and wettability of CA nanofibrous membranes facilitate their close contact with deposited GO colloids. After a portable and fast hot-press process within 700 s at 150 °C, the GO on CA membrane can be facilely reduced to a conductive RGO layer. Moreover, the connection among contiguous CA nanofibers and the interaction between the GO and CA substrate were both highly enhanced, resulting in superior mechanical strength with Young's modulus of 1.3 GPa and small sheet resistance lower than 10 kΩ. Therefore, the conductive RGO/CA membrane was successfully utilized as a strain sensor in a broad deformation range and with versatile deformation types. Moreover, the distinctive mechanical strength under different stretch angles endowed the well-aligned RGO/CA film with intriguing sensitivity against stress direction. Such a cost-effective and environmentally-friendly method can be easily extended to the scalable production of graphene-based flexible electronic textiles.

14.
Ecotoxicol Environ Saf ; 174: 484-490, 2019 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-30856560

RESUMEN

Microorganisms have been widely applied to heavy metal adsorption due to their strong secretion of extracellular polymeric substances (EPS). This study explored the responses of Rhodotorula mucilaginosa (R1, a red yeast with substantial EPS supply) under Pb stress. The maximum sorption of Pb cations by R1 was ~650 mg/L. In particular, despite the declined microbial biomass, the total Pb sorption after incubation was actually elevated in the solution with high Pb concentration. At 0-1000 mg/L Pb(NO3)2 level, the longitudinal sizes of the yeast capsules increased from 2.04 to 2.90 µm. At 1500 mg/L, however, the survived yeast started to lose the membrane integrity of the cells. Meanwhile, the percentages of organic carbon contents of EPS decreased from 40% to 33% when the Pb(NO3)2 concentration raised to 2500 mg/L, confirming the incorporation of Pb2+ cations into the fungal EPS during the sorption. For the survived R1 cells, function of polysaccharides to resist Pb toxicity only worked at extremely high Pb(NO3)2 levels (>= 1500 mg/L). In contrast, proteins showed continuously enhanced ability to resist Pb toxicity, consistent with their increasing content (per cell) in the EPS. Moreover, ATR-IR spectra showed that the intensity of amide II peak at 1540 cm-1 was significantly increased, indicating elevated glutathione (GSH) in EPS. This suggested that GSH could be the critical Pb-binding component in EPS proteins. This study hence elucidated roles of polysaccharides and proteins in EPS under the toxicity caused by heavy metals.


Asunto(s)
Contaminantes Ambientales/toxicidad , Matriz Extracelular de Sustancias Poliméricas/metabolismo , Proteínas Fúngicas/metabolismo , Plomo/toxicidad , Polisacáridos/metabolismo , Rhodotorula/efectos de los fármacos , Adsorción , Biomasa , Contaminantes Ambientales/metabolismo , Plomo/metabolismo , Estrés Oxidativo/efectos de los fármacos , Rhodotorula/crecimiento & desarrollo , Rhodotorula/metabolismo , Rhodotorula/ultraestructura
15.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(5): 1565-70, 2016 May.
Artículo en Zh | MEDLINE | ID: mdl-30001064

RESUMEN

Quartz Volume Diffuser(QVD) is used in the observing system of Space-Borne differential optical absorption spectrometer. The precision of observed solar spectrum directly influences the accuracy of the gas retrievals. Therefore the QVD is required for well Lambert feature to ensure the accuracy of full field solar spectrum, and it can provide uniformity source in the observing view of the instrument. Using bidirectional reflectance distribution function(BRDF) measurement instrument, adopting the powder pressboard of F4(polytetrafluoroethylene(PTFE)), QVD's BRDF is measured by choosing the relative measurement method. Four kinds of QVD's BRDF is obtained in the range of 180~880 nm, the observing view of -70°ï½ž+70°. Two kinds of QVD which has a well Lambert feature are selected by analyzing the QVD's BRDF. The diffuse sunlight measured by QVD and F4 is compared, which show that QVD has well scattering properties with regard to solar spectrum and can be selected as the measuring diffuser. That supports for next Ultraviolet irradiation measurement, atomic oxygen erosion measurement and comparison measurement.

16.
Can J Microbiol ; 61(1): 65-71, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25496139

RESUMEN

The acidophilic Fe-oxidizing and S-oxidizing bacterium YY2 was isolated from the acid drainage of a coalmine. Based on morphological and physiological characteristics and phylogenetic analysis, it was identified as Acidithiobacillus ferrooxidans. Significant differences were observed in the oxidation efficiency and cell morphology when YY2 was cultured in 9K medium with ferrous ion (Fe(2+)), elemental sulfur (S(0)), and pyrite as the sole energy source. YY2 exhibited marked Fe(2+) oxidation activity; 44.2 g · L(-1) FeSO4 · 7H2O was completely oxidized in 30 h, but the rates of S(0) and pyrite oxidization were slower. After 20 days, the efficiencies of oxidizing 10 g · L(-1) S(0) and 10 g · L(-1) pyrite were approximately 9.6% and 20%, respectively. Cells cultured in pyrite as substrate secreted more extracellular polymeric substances than they did when cultured in Fe(2+) or S(0). Additionally, 75% total sulfur removal and 86% pyritic sulfur removal was achieved in a sequencing batch reactor of biodesulfurization of coal.


Asunto(s)
Acidithiobacillus/aislamiento & purificación , Acidithiobacillus/metabolismo , Carbón Mineral/microbiología , Azufre/metabolismo , Acidithiobacillus/clasificación , Acidithiobacillus/genética , Hierro/metabolismo , Datos de Secuencia Molecular , Oxidación-Reducción , Filogenia , Sulfuros/metabolismo
17.
Appl Opt ; 54(31): 9157-66, 2015 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-26560568

RESUMEN

The environmental measuring instrument (EMI) is a nadir-viewing wide-field imaging spectrometer, which adopts spaceborne diffusers in in-flight calibration systems, including an aluminum diffuser and a quartz volume diffuser. Spaceborne diffusers, are the key components of in-flight calibration systems, and are used to introduce sunlight into the EMI. Hemispheric reflectance and bidirectional reflectance distribution function were experimentally measured to analyze spaceborne diffuser performance. Radiation exposure experiments on atomic oxygen, UV, and radiation dose of the spaceborne diffusers were performed at ground level because the EMI works in low Earth orbit space environments. Effects of radiation exposure on spaceborne diffusers were discussed in detail. Protective methods were introduced to reduce the effects of the space environment, and an in-orbit monitoring method was also proposed.

18.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(7): 2049-53, 2015 Jul.
Artículo en Zh | MEDLINE | ID: mdl-26717777

RESUMEN

Spectral calibration of space-born imaging spectrometers based on spectrum-matching technique is presented, which adopts atmospheric absorption lines as the matching lines, and chooses correlation coefficient method as the criteria. In order to simulation the onboard spectral calibration, the spectrum-matching technique is applied on the imaging spectrometers that after the vibration test. The vibration test is able to simulation the launching. The spectral resolution, center wavelength of two-dimensional pixel is determined during onboard spectral calibration. As the calibration results show, the spectral resolution of imaging spectrometers after the vibration test is 0.40 nm, it is the same comparing to the value before the vibration, the wavelength shifts 0.08 nm towards the long wave for the spectral pixels, and the spectral smile is determined for all spatial elements, which shifts towards the short wave direction, with the max smile value is 0.96 nm, the result is similar to that before the vibration. As a result, the spectrum-matching technique is tested and verified.

19.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(9): 2578-82, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26669171

RESUMEN

Space-borne differential optical absorption spectrometer is a nadir viewing wide field imaging spectrometer, which adopts two-dimensional CCD detector arrays. The pixel response non-uniformity exists in each column of spatial dimension, which will introduce high-frequency instrument-related spectral structures in the measurement data. However, the non-uniformity calibration of space-born imaging spectrometer is difficulty due to two factors: the spectral smile effect and the large field of view. For this reason, a method of non-uniformity calibration is discussed in detail. The result shows that the spectral smile effect and non-uniformity of full FOV image are corrected effectively, and high-frequency instrument-related structures in the measurement data are removed.

20.
Plant Physiol ; 162(3): 1378-91, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23735506

RESUMEN

Enhancing drought tolerance without yield decrease has been a great challenge in crop improvement. Here, we report the Arabidopsis (Arabidopsis thaliana) homodomain-leucine zipper transcription factor Enhanced Drought Tolerance/HOMEODOMAIN GLABROUS11 (EDT1/HDG11) was able to confer drought tolerance and increase grain yield in transgenic rice (Oryza sativa) plants. The improved drought tolerance was associated with a more extensive root system, reduced stomatal density, and higher water use efficiency. The transgenic rice plants also had higher levels of abscisic acid, proline, soluble sugar, and reactive oxygen species-scavenging enzyme activities during stress treatments. The increased grain yield of the transgenic rice was contributed by improved seed setting, larger panicle, and more tillers as well as increased photosynthetic capacity. Digital gene expression analysis indicated that AtEDT1/HDG11 had a significant influence on gene expression profile in rice, which was consistent with the observed phenotypes of transgenic rice plants. Our study shows that AtEDT1/HDG11 can improve both stress tolerance and grain yield in rice, demonstrating the efficacy of AtEDT1/HDG11 in crop improvement.


Asunto(s)
Proteínas de Arabidopsis/genética , Oryza/fisiología , Plantas Modificadas Genéticamente , Factores de Transcripción/genética , Ácido Abscísico/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Sequías , Regulación de la Expresión Génica de las Plantas , Oryza/genética , Oryza/crecimiento & desarrollo , Fotosíntesis/genética , Hojas de la Planta/anatomía & histología , Hojas de la Planta/genética , Raíces de Plantas/genética , Estomas de Plantas/genética , Prolina/metabolismo , Estrés Fisiológico/genética , Superóxido Dismutasa/metabolismo , Factores de Transcripción/metabolismo
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