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1.
Sci Total Environ ; 924: 171572, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38461998

RESUMO

Nitrous oxide (N2O) is the third most important greenhouse gas, and can damage the atmospheric ozone layer, with associated threats to terrestrial ecosystems. However, to date it is unclear how extreme precipitation and nitrogen (N) input will affect N2O emissions in temperate desert steppe ecosystems. Therefore, we conducted an in-situ in a temperate desert steppe in the northwest of Inner Mongolia, China between 2018 and 2021, in which N inputs were combined with natural extreme precipitation events, with the aim of better understanding the mechanism of any interactive effects on N2O emission. The study result showed that N2O emission in this desert steppe was relatively small and did not show significant seasonal change. The annual N2O emission increased in a non-linear trend with increasing N input, with a much greater effect of N input in a wet year (2019) than in a dry year (2021). This was mainly due to the fact that the boost effect of high N input (on June 17th 2019) on N2O emission was greatly amplified by nearly 17-46 times by an extreme precipitation event on June 24th 2019. In contrast, this greatly promoting effect of high N input on N2O emission was not observed on September 26th 2019 by a similar extreme precipitation event. Further analysis showed that soil NH4+-N content and the abundance of ammonia oxidizing bacteria (amoA (AOB)) were the most critical factors affecting N2O emission. Soil moisture played an important indirect role in regulating N2O emission, mainly by influencing the abundance of amoA (AOB) and de-nitrification functional microorganisms (nosZ gene). In conclusion, the effect of extreme precipitation events on N2O emission was greatly increased by high N input. Furthermore, in this desert steppe, annual N2O flux is co-managed through soil nitrification substrate concentration (NH4+-N), the abundance of soil N transformation functional microorganisms and soil moisture. Overall, it was worth noting that an increase in extreme precipitation coupled with increasing N input may significantly increase future N2O emissions from desert steppes.


Assuntos
Ecossistema , Nitrogênio , Nitrogênio/análise , Microbiologia do Solo , Nitrificação , Solo/química , Óxido Nitroso/análise
3.
Sci Total Environ ; 915: 169915, 2024 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-38190901

RESUMO

Global nitrogen deposition is significantly altering the carbon (C), nitrogen (N) and phosphorus (P) stoichiometry in terrestrial ecosystems, yet how N deposition simultaneously affects plant-litter-soil-soil microbial stoichiometry in arid grassland is still unclear. In a five-year experimental study conducted in a desert steppe in Northern China, we investigated the effects of N addition on the C:N:P stoichiometry of plants, litter, soil, and soil microbes. We also used structural equation modelling (SEM) exploring the direct or indirect effects of N addition, plant species diversity, functional traits and diversity, soil microbial diversity, soil pH, soil electrical conductivity (EC) and moisture on the stoichiometry in plant-soil system. The results showed that N addition increased the N, P concentrations and N:P in plants, the N concentration and N:P in litter, and the C, N concentrations, C:P and N:P in microbes. Conversely, it decreased the C:N and C:P in plants, and litter C:N. Functional traits, functional dispersion (FDis), soil pH and EC accounted for a substantial proportion of the observed variations in elemental concentrations (from 42 % to 69 %) and stoichiometry (from 9 % to 73 %) across different components. SEM results showed that N addition decreased C:N and C:P in plants and litter by increasing FDis and leaf N content, while increased plant and litter N:P by decreasing leaf C content and increasing specific leaf area, respectively. Furthermore, N addition increased microbial C:P by increasing leaf thickness. We also found the mediating effects of soil pH and EC on C:N, C:P of litter and microbial N:P. Overall, our research suggests that plant functional traits as key predictors of nutrient cycling responses in desert steppes under N addition. This study extends the application of plant functional traits, enhances our understanding of C and nutrient cycling and facilitates predicting the response of desert steppes to N deposition.


Assuntos
Ecossistema , Solo , Solo/química , Microbiologia do Solo , Nitrogênio/análise , Plantas , Fósforo/análise , Carbono/análise , China , Pradaria
5.
Nat Plants ; 9(9): 1451-1467, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37563458

RESUMO

In plants, restoring intercellular communication is required for cell activity in buds during the growth transition from slow to fast growth after dormancy release. However, the epigenetic regulation of this phenomenon is far from understood. Here we demonstrate that lily VERNALIZATION INSENSITIVE 3-LIKE 1 (LoVIL1) confers growth transition by mediating plasmodesmata opening via epigenetic repression of CALLOSE SYNTHASE 3 (LoCALS3). Moreover, we found that a novel transcription factor, NUCLEAR FACTOR Y, SUBUNIT A7 (LoNFYA7), is capable of recruiting the LoVIL1-Polycomb Repressive Complex 2 (PRC2) and enhancing H3K27me3 at the LoCALS3 locus by recognizing the CCAAT cis-element (Cce) of its promoter. The LoNFYA7-LoVIL1 module serves as a key player in orchestrating the phase transition from slow to fast growth in lily bulbs. These studies also indicate that LoVIL1 is a suitable marker for the bud-growth-transition trait following dormancy release in lily cultivars.


Assuntos
Epigênese Genética , Lilium , Glucosiltransferases/genética , Complexo Repressor Polycomb 2 , Regulação da Expressão Gênica de Plantas
6.
Chemosphere ; 335: 139080, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37263510

RESUMO

Important functions of constructed wetland related to biogeochemical processes are mediated by soil microbes and low-temperature damage is the main limiting factor for microbes in winter. However, the response thresholds for active microbial community and enzyme activities to continuous decreases in temperature remain unclear. In this study, total 90 soil samples were collected every week over a 6-week period to track the dynamics of four enzymes involved in cycles of C, N, P and active bacterial community as field soil temperature decreased continuously from 6.62 °C to 0.55 °C. Enzyme activity changed suddenly when the temperature decreased to 4.83 °C, the nitrite reductase activity reduced by 36.2%, while alkaline phosphatase activity is increased by 396%. The cellulase and urease were only marginally influenced by cold stress. Decreased nitrite reductase activities corresponded with loss of nir-type denitrifiers important for nitrite reduction. For cold stress, N-related bacteria were sensitive species. Whereas increased alkaline phosphatase activity may be due to the fact that P-related bacteria were opportunistic species. Key functional taxa connected with degradation of cellulose promoted species coexistence and microbial network stability. The lower and upper temperature thresholds for community change were 4.85 °C and 6.30 °C, respectively. Collectively, these results revealed that microbial taxa involved in C, N and P cycling respond differently to continuous decreases in temperature and higher than 4.85 °C is an ideal environment to prevent loss of microbial diversity and functions in winter, providing a scientific reference for the targeted isolation and cultivation of key microbial taxa in rhizosphere soil and adjusting temperature range to improve the purification capacity of wetlands during low temperature periods.


Assuntos
Microbiota , Áreas Alagadas , Temperatura , Fosfatase Alcalina/metabolismo , Bactérias/metabolismo , Solo/química , Nitrito Redutases/metabolismo , Microbiologia do Solo
7.
Sci Total Environ ; 884: 163902, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37137371

RESUMO

Plant elemental composition and stoichiometry are useful tools for understanding plant nutrient strategy and biogeochemical cycling in terrestrial ecosystems. However, no studies have examined how plant leaf carbon (C), nitrogen (N), and phosphorus (P) stoichiometry responds to abiotic and biotic factors in the fragile desert-grassland ecological transition zone in northern China. Then a systematically designed 400 km transect was established to investigate the C, N, and P stoichiometry of 870 leaf samples of 61 species from 47 plant communities in the desert-grassland transition zone. At the individual level, plant taxonomic groups and life forms rather than climate or soil factors determined the leaf C, N, and P stoichiometry. In addition, leaf C, N, and P stoichiometry (except leaf C) was significantly influenced by soil moisture content in the desert-grassland transition zone. At the community level, leaf C content showed a considerable interspecific variation (73.41 %); however, the variation in leaf N and P content, as well as C:N and C:P ratios, was mainly due to intraspecific variation, which was in turn driven by soil moisture. We suggested that intraspecific trait variation played a key role in regulating community structure and function to enhance the resistance and resilience of plant communities to climate change in the desert-grassland transition zone. Our results highlighted the role of soil moisture content as a critical parameter for modeling the biogeochemical cycling in dryland plant-soil systems.


Assuntos
Ecossistema , Pradaria , Folhas de Planta/química , Plantas/química , China , Nitrogênio/análise , Fósforo/análise , Solo/química
8.
Sci Total Environ ; 861: 160654, 2023 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-36473666

RESUMO

Soil microbe diversity plays a key role in dryland ecosystem function under global climate change, yet little is known about how plant-soil microbe relationships respond to climate change. Altered precipitation patterns strongly shape plant community composition in deserts and steppes, but little research has demonstrated whether plant biodiversity attributes mediate the response of soil microbial diversity to long- and short-term precipitation changes. Here we used a comparative study to explore how altered precipitation along the natural and experimental gradients affected associations of soil bacterial and fungal diversity with plant biodiversity attributes (species, functional and phylogenetic diversity) and soil properties in desert-shrub and steppe-grass communities. We found that along both gradients, increasing precipitation increased soil bacterial and fungal richness in the desert and soil fungal richness in the steppe. Soil bacterial richness in the steppe was also increased by increasing precipitation in the experiment but was decreased along the natural gradient. Plant biodiversity and soil properties explained the variations in soil bacterial and fungal richness from 43 % to 96 % along the natural gradient and from 19 to 46 % in the experiment. Overall, precipitation effects on soil bacterial or fungal richness were mediated by plant biodiversity attributes (species richness and plant height) or soil properties (soil water content) along the natural gradient but were mediated by plant biodiversity attributes (functional or phylogenetic diversity) in the experiment. These results suggest that different mechanisms are responsible for the responses of soil bacterial and fungal diversity to long- and short-term precipitation changes. Long- and short-term precipitation changes may modify plant biodiversity attribute effects on soil microbial diversity in deserts and steppes, highlighting the importance of precipitation changes in shaping relationships between plant and soil microbial diversity in water-limited areas.


Assuntos
Ecossistema , Solo , Microbiologia do Solo , Filogenia , Biodiversidade , Plantas , Bactérias , Água
9.
Environ Sci Pollut Res Int ; 30(9): 24319-24328, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36334210

RESUMO

Extreme droughts strongly impact grassland ecology, both functionally and structurally. However, a comprehensive understanding of the drought impacts on the ecosystem stability is critical for its sustainable development under changing climate. We experimentally report the impact of extreme drought on the temporal stability of aboveground net primary productivity (ANPP) and belowground net primary productivity (BNPP) in a desert steppe of northern China. The relative importance evaluation of extreme drought, soil properties, species asynchrony, taxonomic, functional, and phylogenetic diversity was performed using structural equation modeling (SEM) to measure the temporal ANPP and BNPP stabilities. Our findings suggested that extreme drought decreased BNPP stability but did not affect ANPP stability. Extreme drought reduced taxonomic and phylogenetic diversity, ANPP, and soil water content but did not affect species asynchrony, functional diversity, or BNPP. Species richness, Shannon-Wiener index, and soil water content were positively correlated with BNPP stability. The SEM results showed a drought-mediated indirect weakening of BNPP stability via modification of species richness. Asynchrony of species unrelated to drought, however, directly affected ANPP stability. The mechanisms underlying the response determination of ANPP and BNPP stability to extreme drought in desert steppe varied notably. Depending on the species asynchrony, ANPP reduced by extreme drought could maintain higher stability. However, extreme drought lowered BNPP stability by altering species richness.


Assuntos
Secas , Ecossistema , Filogenia , China , Água , Solo , Pradaria
10.
Front Immunol ; 13: 981502, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36189238

RESUMO

Behçet's syndrome (BS) is a chronic form of relapsing multisystem vasculitis, characterized by recurrent oral and genital ulcers. Intestinal BS is a special type of BS. Volcano-shaped ulcers in the ileocecum are a typical finding of intestinal BS, and punched-out ulcers can be observed in the intestine or esophagus. At present, there is no recognized radical treatment for intestinal BS. Glucocorticoids and immunosuppressants are currently the main drugs used to improve the condition. Although it has been reported that monoclonal anti-TNF antibodies may be effective for some refractory intestinal BS, further randomized, prospective trials are necessary to confirm these findings. Some patients are restricted from using biological agents because of serious allergic reactions of drugs, inconvenient drug injections or the impact of the novel coronavirus epidemic. If endoscopic remission (endoscopic healing) is not achieved for a prolonged period of time, serious complications, such as perforation, fistula formation, and gastrointestinal bleeding can be induced. Therefore, it is necessary to develop new treatment methods for controlling disease progression. We reviewed the relevant literature, combined with the analysis of the correlation between the pathogenesis of BS and the mechanism of Janus kinase (JAK) inhibition, and considered that tofacitinib (TOF) may be effective for managing refractory intestinal BS. We report for the first time that four patients with severe refractory intestinal BS were successfully treated with TOF. We hope to provide valuable information on JAK inhibitors as potential therapeutic targets for the treatment of severe refractory intestinal BS.


Assuntos
Síndrome de Behçet , Inibidores de Janus Quinases , Piperidinas , Pirimidinas , Anticorpos Monoclonais/uso terapêutico , Síndrome de Behçet/tratamento farmacológico , Fatores Biológicos/uso terapêutico , COVID-19/epidemiologia , Humanos , Imunossupressores/uso terapêutico , Intestinos/patologia , Inibidores de Janus Quinases/uso terapêutico , Janus Quinases , Piperidinas/uso terapêutico , Estudos Prospectivos , Pirimidinas/uso terapêutico , Inibidores do Fator de Necrose Tumoral , Úlcera/tratamento farmacológico
11.
Front Plant Sci ; 13: 983600, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36147225

RESUMO

Drought greatly affects the growth and development of garden plants and affects their ornamental value. WRKY transcription factors make up one of the largest transcription factor families in plants and they play an important role in the plant response to drought stress. However, the function of the WRKY gene in response to drought stress in Iris germanica, which is commonly used in landscaping, has not been studied. In this study, we isolated two WRKY transcription factor genes from Iris germanica, IgWRKY50 and IgWRKY32, which belong to Group II and Group III of the WRKY family, respectively. IgWRKY50 and IgWRKY32 could be induced by PEG-6000, high temperature and ABA in Iris germanica. IgWRKY50 and IgWRKY32 could quickly respond to drought and they peaked at 3 h after PEG-6000 treatment (19.93- and 23.32-fold). The fusion proteins IgWRKY50-GFP and IgWRKY32-GFP were located in the nucleus of mesophyll protoplasts of Arabidopsis. The overexpression of the IgWRKY50 and IgWRKY32 genes improved the osmotic tolerance of transgenic Arabidopsis, mainly exhibited by the transgenic plants having a higher germination rate and a longer total root length on 1/2 MS medium containing mannitol. Under PEG-6000 stress, the transgenic plants had higher stomatal closure than the wild type (WT). Under natural drought stress, the water loss rate of the isolated leaves of transgenic Arabidopsis was lower than that of WT, the contents of proline (Pro) and soluble protein (SP) and the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in the transgenic plants were higher, but the content of malondialdehyde (MDA) was lower. Furthermore, the expression of several stress-related genes (RD29A, DREB2A, PP2CA, and ABA2) was significantly increased in IgWRKY50- and IgWRKY32- overexpressing transgenic Arabidposis plants after drought treatment. These results suggest that IgWRKY50 and IgWRKY32, as two positive regulators, enhance the drought resistance of transgenic Arabidopsis by mediating the ABA signal transduction pathway. IgWRKY50 and IgWRKY32 can be used as candidate genes for molecular breeding of drought resistance in Iris.

12.
Front Microbiol ; 13: 945847, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35992685

RESUMO

Fertilization is an effective agronomic strategy to improve the efficiency of phytoextraction by Salix integra Thunb. However, the specific effects of the simultaneous application of nitrogen (N) and sulfur (S) fertilizers in the rhizosphere remain unclear. We investigated the bioavailability of lead (Pb) and Cadmium (Cd) along with the microbial metabolic functions and community structure in the rhizosphere soil of S. integra after the application of N (0, 100, and 200 kg·ha-1·year-1) and S (0, 100, and 200 kg·ha-1·year-1) fertilizers for 180 days. The simultaneous application of N and S fertilizers significantly enhanced the absorption of Pb and Cd by S. integra, whereas this effect was not observed for the single application of N or S fertilizer. The contents of acid-soluble Pb and Cd in the rhizosphere soil significantly increased after either single or combined fertilize applications. The microbial metabolic activity was enhanced by the N and S fertilizers, whereas the microbial diversity markedly decreased. The metabolic patterns were mainly affected by the concentration of N fertilizer. The dominant fungi and bacteria were similar under each treatment, although the relative abundances of the dominant and special species differed. Compared to the N200S100 and N200S200 treatments, the N100S100 and N100S200 treatments resulted in fewer pathogenic fungi and more rhizosphere growth-promoting bacteria, which promoted phytoremediation by S. integra. Redundancy analysis indicated that the pH and nitrate content were the key factors affecting the structure of the microbial community. Collectively, the results suggest interactive effects between N and S fertilizers on the rhizosphere soil, providing a potential strategy for plant-microbial remediation by S. integra.

13.
Cancer Gene Ther ; 29(11): 1648-1661, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35661832

RESUMO

Gastric cancer (GC) is one of the most common malignancies, leading to millions of deaths each year. Here, we investigated the molecular mechanisms of GC, with a focus on circXRCC5/miR-655-3p/RREB1/UBA2 axis. circXRCC5 was identified in 62 paired cancer specimens and adjacent normal tissues by genome-wide bioinformatics analysis and verified by qRT-PCR and Sanger sequencing. Knockdown or exogenous expression of circXRCC5 was performed to validate the functional significance of circXRCC5 using both in vitro and in vivo assays, including CCK-8, colony formation, EdU incorporation, transwell system, as well as animal experiments. RNA immunoprecipitation, biotinylated RNA pull-down, ChIP, and dual-luciferase assays were employed to validate the regulatory network of circXRCC5/miR-655-3p/RREB1/UBA2. Frequently elevated circXRCC5 in GC tissues and cell lines was associated with poor prognosis of GC patients. Functionally, circXRCC5 overexpression facilitated GC cell proliferation, migration, and invasion, as well as promoted tumor growth and metastasis in vivo. Mechanistically, circXRCC5 served as a sponge of miR-655-3p to induce upregulation of RREB1. RREB1 was identified as a transcriptional activator of UBA2, thus contributing to GC tumorigenesis. Moreover, RNA binding protein (RBP) HNRNPC was proved to interact with circXRCC5 to promote circXRCC5 biogenesis. Collectively, circXRCC5 facilitates GC progression through the HNRNPC/circXRCC5/miR-655-3p/RREB1/UBA2 axis, which might bring novel therapeutic strategies for GC treatment.


Assuntos
MicroRNAs , Neoplasias Gástricas , Animais , Neoplasias Gástricas/patologia , MicroRNAs/genética , MicroRNAs/metabolismo , Regulação Neoplásica da Expressão Gênica , Proliferação de Células/genética , Retroalimentação , Linhagem Celular Tumoral
14.
Crit Rev Oncol Hematol ; 176: 103732, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35697233

RESUMO

Prostate cancer (PCa) is a highly prevalent disease that affects men's health worldwide and is the second most common malignancy in males. Ferroptosis is a novel form of programmed cell death characterized by iron overload and the accumulation of lipid peroxidation, which differs from the regulated cell death modes of necrosis, apoptosis, and autophagy. Substantial progress has been achieved in researching the occurrence and regulatory mechanisms of ferroptosis, which is closely associated with cancer initiation, progression, and suppression and is expected to become a new breakthrough point in the PCa treatment. This review will summarize the mechanisms involved in PCa, and we detail the molecular mechanisms of ferroptosis and its role in PCa treatment.


Assuntos
Ferroptose , Sobrecarga de Ferro , Neoplasias da Próstata , Apoptose/genética , Ferroptose/genética , Humanos , Peroxidação de Lipídeos , Masculino , Neoplasias da Próstata/genética , Neoplasias da Próstata/terapia
15.
Comput Math Methods Med ; 2022: 7169353, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35529255

RESUMO

The prevalence of lung cancer induced by cigarette smoking has increased over time. Long noncoding (lnc) RNAs, regulatory factors that play a role in human diseases, are commonly dysregulated in lung cancer. Cigarette smoking is closely related to changes in lncRNA expression, which can affect lung cancer. Herein, we assess the mechanism of lung cancer initiation induced by smoking. To calculate the impact of smoking on the survival of patients with lung cancer, we extracted data from The Cancer Genome Atlas and Gene Expression Omnibus databases and identified the differentially expressed genes in the lung cancer tissue compared to the normal lung tissue. Genes positively and negatively associated with smoking were identified. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and Cytoscape analyses were performed to determine the function of the genes and the effects of smoking on the immune microenvironment. lncRNAs corresponding to smoking-associated genes were identified, and a smoking-related lncRNA model was constructed using univariate and multivariate Cox analyses. This model was used to assess the survival of and potential risk in patients who smoked. During screening, 562 differentially expressed genes were identified, and we elucidated that smoking affected the survival of patients 4.5 years after the diagnosis of lung cancer. Furthermore, genes negatively associated with smoking were closely associated with immunity. Twelve immune cell types were also found to infiltrate differentially in smokers and nonsmokers. Thus, the smoking-associated lncRNA model is a good predictor of survival and risk in smokers and may be used as an independent prognostic factor for lung cancer.


Assuntos
Neoplasias Pulmonares , RNA Longo não Codificante , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Humanos , Neoplasias Pulmonares/genética , Prognóstico , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Fumar/efeitos adversos , Microambiente Tumoral
16.
Front Microbiol ; 13: 1074841, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36704553

RESUMO

Soil microbial diversity, composition, and function are sensitive to global change factors. It has been predicted that the temperature and precipitation will increase in northern China. Although many studies have been carried out to reveal how global change factors affect soil microbial biomass and composition in terrestrial ecosystems, it is still unexplored how soil microbial diversity and composition, especially in microbial functional genes, respond to increasing precipitation and warming in a semiarid grassland of northern China. A field experiment was established to simulate warming and increasing precipitation in a temperate semiarid grassland of the Horqin region. Soil bacterial (16S) and fungal (ITS1) diversity, composition, and functional genes were analyzed after two growing seasons. The result showed that warming exerted negative effects on soil microbial diversity, composition, and predicted functional genes associated with carbon and nitrogen cycles. Increasing precipitation did not change soil microbial diversity, but it weakened the negative effects of simulated warming on soil microbial diversity. Bacterial and fungal diversities respond consistently to the global change scenario in semiarid sandy grassland, but the reasons were different for bacteria and fungi. The co-occurrence of warming and increasing precipitation will alleviate the negative effects of global change on biodiversity loss and ecosystem degradation under a predicted climate change scenario in a semiarid grassland. Our results provide evidence that soil microbial diversity, composition, and function changed under climate change conditions, and it will improve the predictive models of the ecological changes of temperate grassland in future climate change scenarios.

17.
Sci Total Environ ; 804: 150172, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34798732

RESUMO

Desert soils are an important sink of atmospheric methane (CH4) and regulate the global CH4 budget. However, it is still unclear how CH4 fluxes respond to precipitation changes in desert-steppe soils. Therefore, a two-year in situ control experiment was conducted to investigate the effect of precipitation changes on CH4 uptake in desert steppe of Inner Mongolia in northwest China and its driving mechanism. The result showed that this desert steppe was an important sink of CH4, with an annual uptake of 2.93 (2.64-3.22) kg C ha-1. It was found that CH4 uptake was reduced significantly for decreasing precipitation, especially in spring and summer. In contrast, an increasing trend of CH4 uptake was observed for increasing precipitation, although it was not statistically significant. Further analyses found that CH4 uptake was more sensitive to decreasing precipitation than increasing precipitation. This may be mainly due to the fact that only moderate water-filled pore space (WFPS) induced by precipitation promoted CH4 uptake, while too-high (>32%) or too-low WFPS inhibited its uptake. A structural equation model showed that the copy number of the pmoA functional gene was the most important factor affecting CH4 uptake. In contrast, soil moisture had a very important indirect effect on CH4 uptake, mainly through significantly affected soil porosity, the above-ground plant biomass and NO3--N content, further affected CH4 uptake. Overall, CH4 sinks in desert steppe was still mainly controlled by methane-oxidizing bacteria containing the key functional gene pmoA and WFPS. Therefore, precipitation plays an important role in regulating the intensity of CH4 sinks in desert steppe, while it is worth noting that too-little precipitation will significantly weaken CH4 sinks.


Assuntos
Metano , Methylococcaceae , China , Metano/análise , Estações do Ano , Solo
18.
Front Microbiol ; 12: 730117, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34603260

RESUMO

Afforestation with trees and shrubs around cropland can effectively decrease soil degradation and avoid sand storms, but subsequent modification of litter quality accelerates the degradation of native organic matter via the soil priming effect (PE). Although carbon accumulation in agricultural soils after afforestation was widely studied, little is known about the extent to which soil organic carbon (SOC) mineralization is induced by complex residue input in agro-forest-grass composite ecosystems. Here, we mixed corn field soil and litter of afforestation tree and shrub species together in a micro-environment to quantify the effects of litter-mixture input on farmland soil priming associated with afforestation. Additionally, we studied the responses of bacterial and fungal species to litter chemistry, with the aim to identify the litter and microbial driver of soil priming. The results showed that soil priming was accelerated by different litter addition which varied from 24 to 74% of SOC mineralization, suggesting that priming intensity was relatively flexible and highly affected by litter quality. We also find that the macro-chemistry (including litter carbon, nitrogen, lignin, and cellulose) directly affects priming intensity, while micro-chemistry (including litter soluble sugar, water-soluble phenol, methanol-soluble phenol, and condensed tannin) indirectly influences priming via alteration to dominant bacterial taxa. The stepwise regression analysis suggested that litter nitrogen and cellulose were the critical litter drivers to soil priming (r 2 = 0.279), and the combination of bacterial phylum Proteobacteria, Firmicutes, Bacteroidetes, Acidobacteria, and fungal taxa Eurotiomycetes was a great model to explain the priming intensity (r 2 = 0.407).

19.
Materials (Basel) ; 14(20)2021 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-34683544

RESUMO

Infrared (IR) microlens arrays (MLA) have attracted increasing interest for use in infrared micro-optical devices and systems. However, the beam homogenization of IR laser light is relatively difficult to achieve because most materials absorb strongly in the IR wavelength band. In this paper, we present a new method for the application of double-sided quasi-periodic chalcogenide glass (ChG) MLAs to infrared laser homogenization systems. These are non-regular arrays of closely spaced MLAs. The double-sided MLAs were successfully prepared on the ChG surface using a single-pulse femtosecond laser-assisted chemical etching technique and a precision glass molding technique. More than two million close-packed microlenses on the ChG surface were successfully fabricated within 200 min. By taking advantage of ChG's good optical performance and transmittance (60%) in the infrared wavelength band (1~11 µm), the homogenization of the IR beam was successfully achieved using the ChG quasi-periodic MLA.

20.
Genes (Basel) ; 12(10)2021 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-34681029

RESUMO

Bud dormancy is an evolved trait that confers adaptation to harsh environments, and affects flower differentiation, crop yield and vegetative growth in perennials. ABA is a stress hormone and a major regulator of dormancy. Although the physiology of bud dormancy is complex, several advancements have been achieved in this field recently by using genetics, omics and bioinformatics methods. Here, we review the current knowledge on the role of ABA and environmental signals, as well as the interplay of other hormones and sucrose, in the regulation of this process. We also discuss emerging potential mechanisms in this physiological process, including epigenetic regulation.


Assuntos
Diferenciação Celular/genética , Epigênese Genética/genética , Flores/genética , Dormência de Plantas/genética , Aclimatação/genética , Produtos Agrícolas/genética , Produtos Agrícolas/crescimento & desenvolvimento , Flores/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas/genética , Reguladores de Crescimento de Plantas/genética
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