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1.
Microb Ecol ; 85(4): 1382-1395, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-35583685

RESUMO

Understanding how microbial communities adapt to environmental stresses is critical for interpreting ecological patterns and microbial diversity. In the case of the Gobi Desert, little is known on the environmental factors that explain hypolithic colonization under quartz stones. By analyzing nine hypolithic communities across an arid gradient and the effects of the season of the year in the Hexi Corridor of this desert, we found a significant decrease in hypolithic colonization rates (from 47.24 to 15.73%) with the increasing drought gradient and found two distinct communities in Hot and Cold samples, which survived or proliferated after a hot or a cold period. While Cold communities showed a greater species diversity and a predominance of Cyanobacteria, Hot communities showed a predominance of members of the Proteobacteria and the Firmicutes. In comparison, Cold communities also possessed stronger functions in the photosynthesis and carbon metabolism. Based on the findings of this study, we proposed that the hypolithic communities of the Hexi Corridor of the Gobi Desert might follow a seasonal developmental cycle in which temperature play an important role. Thus after a critical thermal threshold is crossed, heterotrophic microorganisms predominate in the hot period, while Cyanobacteria predominate in the cold period.


Assuntos
Cianobactérias , Microbiota , Estações do Ano , Clima Desértico , Cianobactérias/genética , Temperatura , Microbiologia do Solo
3.
Int J Syst Evol Microbiol ; 69(2): 397-403, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30543508

RESUMO

A Gram-stain-positive, aerobic, non-motile and mycolic-acid-containing strain, designated Y48T, was isolated from soil contaminated by crude oil located in the northern margin of the Qaidam Basin. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain Y48T belongs to the genus Nocardia and is closely related to N. cummidelens DSM 44490T (99.0 % similarity), N. soli DSM 44488T (99.0 %), N. lasii 3C-HV12T (98.9 %), N. salmonicida NBRC 13393T (98.6 %), N. ignorata NBRC 108230T (98.6 %) and N. coubleae NBRC 108252T (98.6 %). The average nucleotide identity and DNA-DNA hybridization values between strain Y48T and the reference strains were 75.9-84.5 and 27.5-29.0 %, respectively, values that were below the thresholds for species delineation. Chemotaxonomic analysis indicated that the major fatty acids of strain Y48T were C16 : 0, summed feature 3 (C16 : 1ω6c/C16 : 1ω7c), C18 : 1ω9c and C18 : 0 10-methyl (TBSA). The respiratory quinone was MK-8(H4, ω-cycl). The polar lipid profile was composed of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside, two glycolipids and three unidentified lipids. The cell-wall hydrolysates contained meso-diaminopimelic acid, with ribose, arabinose, glucose and galactose as whole-cell sugars. A combination of 16S rRNA gene sequence analysis, and phenotypic and chemotaxonomic characterizations demonstrated that strain Y48T represents a novel species of the genus Nocardia, for which the name Nocardia mangyaensis sp. nov. is proposed. The type strain is Y48T (=JCM 32795T=CGMCC 4.7494T).


Assuntos
Nocardia/classificação , Poluição por Petróleo , Filogenia , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Nocardia/isolamento & purificação , Hibridização de Ácido Nucleico , Petróleo , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Poluentes do Solo , Tibet , Vitamina K 2/análogos & derivados , Vitamina K 2/química
4.
Ying Yong Sheng Tai Xue Bao ; 29(2): 678-686, 2018 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-29692085

RESUMO

Non-invasive microsensing technique has been widely used in evaluating the adaptive responses of plant cells and tissues to abiotic stresses. One of the representative techniques is the microelectrode ion flux estimation (MIFE), which allows concurrent quantification of net fluxes with high spatial and temporal resolution. More importantly, this technique permits simultaneous recording of ion concentration and mobility with less intervention to the in situ physiological status. With the availability of such advanced technique, the last three decades have seen a significant progress towards the role of ion signaling in a variety of abiotic stresses including salinity, extreme temperature, osmotic stress, hypoxia, and drought. In this review, we gave a brief introduction of the MIFE working principles and focused on its applications in detecting ion responses to various abiotic stresses.


Assuntos
Secas , Microeletrodos , Estresse Fisiológico , Íons/análise , Salinidade , Transdução de Sinais
5.
Ecotoxicol Environ Saf ; 147: 913-918, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28985652

RESUMO

The remobilization of cadmium (Cd) from shoots to grain is the key process to determine the Cd accumulation in grain. The apoplastic pH of plants is an important factor and signal in influencing on plant responding to environmental variation and inorganic elements uptake. It is proposed that pH of rice plants responds and influences on Cd remobilization from shoots to grain when rice is exposed to Cd stress. The results of hydroponic experiment showed that: pH of the rice leaf vascular bundles among 3 cultivars was almost increased, pH value of 1 cultivar was slightly increasing when rice plants were treated with Cd. The decrease degree of H+ concentration in leaf vascular bundles was different among cultivars. The cultivar with higher decreasing in H+ concentration, showed higher Cd transfer efficiency from shoots to grain. The H+ concentration of leaf vascular bundles under normal condition was negatively correlated to cadmium accumulation in leaf. Moreover, pH change was related to Cd accumulation in shots and remobilization from shoots to grain. Uncovering the role of pH response is a key component for the understanding Cd uptake and remobilization mechanism for rice production.


Assuntos
Cádmio/metabolismo , Grão Comestível/metabolismo , Oryza/metabolismo , Brotos de Planta/metabolismo , Feixe Vascular de Plantas/química , Poluentes do Solo/metabolismo , Transporte Biológico , Cádmio/análise , Grão Comestível/química , Concentração de Íons de Hidrogênio , Hidroponia , Modelos Teóricos , Oryza/química , Folhas de Planta/química , Brotos de Planta/química , Poluentes do Solo/análise , Especificidade da Espécie
6.
J Zhejiang Univ Sci B ; 15(9): 801-8, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25183034

RESUMO

ß-Amylase activity (BAA) and thermostability (BAT) are important traits for malt quality. In this study, 138 Tibetan annual wild barley accessions and 20 cultivated genotypes differing in BAA were planted and analyzed in 2009 and 2012. Significant differences were detected among genotypes in BAA and BAT. The cultivated genotypes had a mean BAA of 1137.6 U/g and a range of from 602.1 to 1407.5 U/g, while the wild accessions had a mean of 1517.9 U/g and a range of from 829.7 to 2310.0 U/g. The cultivated genotypes had a mean relative residual ß-amylase activity (RRBAA) of 61.6% and a range of from 22.2% to 82.3%, while the wild barleys had a mean of 57.8% and a range of from 21.9% to 96.1%. Moreover, there was a significant difference among genotypes in the response of RRBAA to the temperature and duration of heat treatment. The wild barleys had wider variation in BAA and BAT than cultivated genotypes.


Assuntos
Hordeum/enzimologia , Hordeum/genética , Proteínas de Plantas/metabolismo , beta-Amilase/metabolismo , Produtos Agrícolas/enzimologia , Produtos Agrícolas/genética , Estabilidade Enzimática , Genótipo , Temperatura Alta , Proteínas de Plantas/genética , Tibet , beta-Amilase/genética
7.
Environ Toxicol Chem ; 32(6): 1420-5, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23417770

RESUMO

The effect of sodium chloride (NaCl) on cadmium (Cd) uptake, translocation, and oxidative stress was investigated using 2 tobacco cultivars differing in Cd tolerance. The growth inhibition of the tobacco plants exposed to Cd toxicity was in part alleviated by moderate addition of NaCl in the culture solution. Cadmium concentration of shoots and roots in the 2 cultivars increased with increasing Cd levels in the solution and decreased with the addition of NaCl. The addition of NaCl could alleviate the oxidative stress caused by Cd toxicity, as reflected by reduced production of malondialdehyde and recovered or enhanced activities of antioxidative enzymes catalase and glutathione peroxidase. The results also showed that the enhancement of antioxidative enzyme activity by NaCl for the tobacco plants exposed to Cd stress is related to induced Ca signaling.


Assuntos
Adaptação Fisiológica , Cádmio/toxicidade , Nicotiana/fisiologia , Cloreto de Sódio/metabolismo , Poluentes do Solo/toxicidade , Catalase/metabolismo , Glutationa Peroxidase/metabolismo , Malondialdeído/metabolismo , Oxirredução , Estresse Oxidativo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Cloreto de Sódio/química , Solo/química , Poluentes do Solo/metabolismo , Nicotiana/efeitos dos fármacos
8.
Artigo em Chinês | MEDLINE | ID: mdl-16261198

RESUMO

OBJECTIVE: To study the preventive and therapeutic effects of recombinant IFN-alpha2b for nasal spray on SARS-CoV infection in Macaca mulata (rhesus monkey). METHODS: Ten rhesus monkeys were divided into two groups, 5 in interferon group, and 5 in control group. Before and after SARS-CoV attack, the virus was detected in samples such as pharyngeal swab in all the two groups by Real-time PCR (RT-PCR) and virus isolation was performed. RESULTS: After virus attack, the level of SARS-CoV-specific IgG and neutralizing antibody were induced by SARS-CoV in the interferon group was weaker than in control group. Hematology items showed no apparent changes after virus attack in treated group. Through pathological examination, the morphology of the lung tissues of two Macaques in the treated group was normal, while the other three displayed the interstitial pneumonia with the thickened septum and infiltration with mononuclear cells. Among which, one monkey showed part of thickened septum fused with each other. These lesions in the interferon treated animals were similar to those seen in the animals in control group, but with smaller scope of pathological changes. No significant abnormity was detected in other organs. CONCLUSION: Recombinant IFN-alpha2b could effectively interdict or weaken SARS-CoV injury in monkeys.


Assuntos
Interferon-alfa/uso terapêutico , Doenças dos Macacos/tratamento farmacológico , Síndrome Respiratória Aguda Grave/tratamento farmacológico , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/efeitos dos fármacos , Animais , Antivirais/uso terapêutico , Chlorocebus aethiops , Modelos Animais de Doenças , Feminino , Interferon alfa-2 , Pulmão/efeitos dos fármacos , Pulmão/patologia , Pulmão/virologia , Macaca mulatta , Masculino , Doenças dos Macacos/prevenção & controle , Doenças dos Macacos/virologia , Distribuição Aleatória , Proteínas Recombinantes , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/isolamento & purificação , Síndrome Respiratória Aguda Grave/prevenção & controle , Síndrome Respiratória Aguda Grave/virologia , Células Vero
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