SOIL BIOLOGY & BIOCHEMISTRY
·
2024
·
IF 9.8
Min Li,Jipeng Wang,Na Li,Qitong Wang,Peipei Zhang,Qiuhong Feng,Huajun Yin
Root activity creates a unique microbial hotspot in the rhizosphere, profoundly regulating free-living nitrogen fixation (FLNF). However, empirical assessments of rhizosphere FLNF and its ecological consequences for nitrogen (N) budgets remain lacking, particularly for different root functional modules. Here, we separately collected rhizosphere soils attached to two root functional modules, absorptive roots and transport roots, and investigated the rates ( 15 N 2 incorporation) and regulators of rhizosphere FLNF in a N-limited subalpine coniferous forest. The measured rates were further extrapolated to annual fluxes based on the volume of the rhizosphere and the relationship between FLNF rate and temperature. We found that absorptive roots drove significantly higher rhizosphere FLNF rates than did transport roots (12.2 vs. 7.5 ng N g −1 d −1 ), with both rhizosphere compartments exhibiting rates well exceeding those in the bulk soil (0.9 ng N g −1 d −1 ). The FLNF rates were positively correlated with soil organic carbon content but showed no significant relationship with the abundance or composition of the diazotrophic community. Moreover, when extrapolated to the ecosystem level the FLNF fluxes were 2-fold greater in the rhizosphere of absorptive roots than in that of transport roots (0.13 vs. 0.04 kg N ha −1 yr −1 ). Taken together, despite representing only 6.0% of the soil volume, the two rhizosphere compartments contributed as much as 47.2% to the total soil FLNF fluxes. Overall, we provide empirical evidence that despite its limited volume, the rhizosphere contributes disproportionately to the FLNF in subalpine forest soils. Our findings also underscore the critical role of root functional differentiation in regulating rhizosphere FLNF, which is essential for integrating this process into the ecosystem-level N cycle.
研究领域:
生态学
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微生物学
·
土壤学
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DOI
高影响因子
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
·
2025
·Vol. 122
·期 6
·e2417735122
·
IF 9.1
Wangshu Mou,Ria Khare,Joanna K. Polko,Isaiah Taylor,Juan Xu,Dawei Xue,Philip Benfey,Bram Van de Poel,Caren Chang,Joseph J. Kieber
In seed plants, the canonical role of 1-aminocyclopropane-1-carboxylic acid (ACC) is to serve as the precursor in the biosynthesis of the phytohormone ethylene, and indeed, ACC treatment is often used as a proxy for ethylene treatment. Increasing evidence suggests that ACC can also act independently of ethylene to regulate various aspects of plant growth and development. Here, we explore the effects of ACC on Arabidopsis thaliana root growth and the mechanisms by which it acts. ACC inhibits growth of the primary root in Arabidopsis seedlings when ethylene signaling is blocked, which becomes evident after 36 h of treatment with ACC. This reduced root growth is in part the result of suppressed cell proliferation in the root meristem resulting from altered expression of a key regulator of stem cell niche activity, WOX5. ACC also promotes lateral root (LR) development, in contrast to ethylene, which inhibits LR formation. Transcriptomic analysis of roots revealed no significant changes in gene expression after 45 min or 4 h of ACC treatment, but longer treatment times revealed a large number of differentially expressed genes, including the downregulation of the expression of a small group of phylogenetically related CLE peptides. Reduced expression of these group 1 CLEs in response to ACC leads to the activation of a transcription factor, LBD18, which promotes LR development. These results suggest that ACC acts to modulate multiple aspects of Arabidopsis root growth independently of ethylene via distinct transcriptional effects in the root meristem and LR precursor cells.
研究领域:
植物学
·
分子生物学
·
遗传学
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产品关联
DOI
PubMed
高影响因子
PLANT AND SOIL
·
2021
·Vol. 465
·期 1
·385-402
·
IF 4.192
Wang Baoying,Xia Qing,Li Yunlong,Zhao Jun,Yang Shaozhou,Wei Fugang,Huang Xinqi,Zhang Jinbo,Cai Zucong
Background and aims Root rot is a catastrophic disease of perennial medicinal plants which could be caused by various soil-borne fungal pathogens. However, the understanding of the composition and diversity of root rot pathogenic fungi, their successions and potential drivers remains limited. Methods Sanqi ginseng ( Panax notoginseng ) was selected as a model plant and the rhizosphere soils of root rot-infected Sanqi ginseng at different growth years were collected. Phenolic acid content, pathogen abundance, and fungal microbiota were examined by using the high-performance liquid chromatography (HPLC), real-time PCR and Miseq sequencing. Results Pathogenic agents dominated in the rhizospheric fungal microbiota of rotten Sanqi ginseng and mainly comprised of Ilyonectria , Plectosphaerella , Clonostachys , Gibberella , Pestalotiopsis , Fusarium , and Chalara , with Ilyonectria and Fusarium being most abundant. The composition of pathogenic microbiota, but not α-diversity indices, changed considerably with Sanqi ginseng growth. The shifts of phenolic acid profile were an important driver in changes of rhizosphere pathogenic microbiota, and same phenolic acid exerted distinct functions on differential pathogenic taxa. Particularly, the contents of p -coumaric acid, ferulic acid, and benzoic acid were positively correlated with the abundance of genus Fusarium and negatively correlated with the abundance of genus Ilyonectria . Conclusions Root rot-infected Sanqi ginseng rhizosphere harbors dynamically pathogenic microbiota driven by the shift of phenolic acids. This study provides insights into the composition, variation, and driver of root rot pathogenic microbiota; these insights are important for the development of targeted measure for the prevention and control of root rot diseases.
研究领域:
微生物学
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植物病理学
·
土壤学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL POLLUTION
·
2024
·
IF 7.6
Lijuan Luo,Junhui Wu,Xueting Yuan,Xinyan Li,Bi Huang,Shanshan Chen,Jiewei Deng,Tiangang Luan
Psychoactive substances abuse is a global issue, with the methamphetamine (METH) being the most used and produced illicit substance in recent years. METH has been recognized as emerging contaminants in aquatic ecosystems. Research on the removal of METH from surface water is still lacking in-depth exploration. The effects of key aqueous environmental factors on the photodegradation of METH were investigated in this study. NO₃ ⁻ , Fe 3+ and dissolved organic matter (DOM) enhanced the photodegradation of METH, respectively, with degradation rates increasing as their concentrations increased. When HCO₃ ⁻ coexisted with NO₃ ⁻ , it exhibited dual effects on METH photodegradation: low concentrations inhibited the process, whereas high concentrations promoted it. The primary photodegradation products of METH, such as OH-METH, (OH) 2 -METH, AMP and NO 2 -OH-METH, were identified. The latter two compounds were newly discovered in this study. The mechanism of NO₃ ⁻ , HCO₃ ⁻ and Fe 3+ accelerating the photodegradation of METH in water was proposed to proceed via the generation of hydroxyl radical (HO∙), leading to the oxidation of METH, along with the involvement of nitro radical (∙NO 2 ) and carbonate radical (CO 3 •- ).
研究领域:
环境科学
·
化学
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产品关联
DOI
PubMed
高影响因子
Biomaterials Science
·
2019
·Vol. 7
·期 5
·2152-2164
·
IF 5.251
Tianqi Yi,Jun Huang,Xuewen Chen,Haiyun Xiong,Yang Kang,Jun Wu
Nano-drug delivery systems are widely used in medical diagnoses, tumour drug delivery and other fields due to their unique advantages. Thus, the preparation of more biocompatible nanocarriers by modifying natural materials has become a research hotspot in recent years. As a type of abundant and environment-friendly natural material, puerarin has been proven to be effective in the treatment of many diseases. However, its low solubility and low oral utilization limit its use. In this study, a novel biocompatible nanomaterial was developed. Puerarin was modified with an unsaturated olefin via acryloyl chloride and the amphiphilic polymer poly-puerarin was finally obtained through free radical polymerization, which was used in the preparation of a drug delivery system. Poly-puerarin nanoparticles (PPue NPs) were prepared by nanoprecipitation and used as a platform to load paclitaxel (PPue@PTX NPs). Physicochemical characterization showed that the nanoparticle size was around 70 nm and the drug loading efficiency of PTX was up to 23.8%. The cytotoxicity test revealed that the modified puerarin derivatives, PPue, exhibited good biocompatibility even at large doses of 100 μg mL−1 and the PPue@PTX NPs still maintained the excellent anti-cancer effect of PTX. The in vitro cellular uptake assay demonstrated that the PPue@PTX NPs were rapidly uptaken by CT26 cells. In the in vivo experiments, the PPue@PTX NPs featured rapid aggregation and slow clearance and the most significant effect of inhibiting tumour growth among all the treatment groups. Therefore, our work provides a new strategy for the modification of natural drugs and PPue is expected to become a new safe and reliable nano-drug delivery platform.
研究领域:
药学
·
生物材料
·
肿瘤学
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产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2024
·
IF 10.8
Yanyan Chen,Hao Deng,Pengliang Liang,Heng Yang,Long Jiang,Jing Yin,Jia Liu,Shuying Shi,Huiqiang Liu,Yuxiang Li,Ying Xiong
Sustainable photocatalysis can effectively reduce the radioactive 99TcO4– to less soluble TcO2·nH2O(s), but the reduction efficiency is highly susceptible to coexisting nitrate (NO3–). Here, we quantitatively investigate photocatalytic remediation conditions for Tc-contaminated water stimulated by the analogue perrhenate (ReO4–) in the presence of NO3–, and we elucidate the influence mechanism of NO3– by in situ characterizations. The interfering NO3– can compete with Re(VII) for the carbonyl radical (·CO2–) produced by formic acid (HCOOH) oxidation to generate nitrogen-containing products such as NH4+, NO2–, and NOx, resulting in the decrease in the Re(VII) reduction ratio. Under the conditions of 4% (volume ratio) HCOOH and pH = 3, the yield of NOx is the lowest, and the selectivity of N2 reaches 93%, which makes the overall reaction more in line with the pollution-free concept. The X-ray absorption fine structure reveals that the redox product Re(IV) mainly exists in the form of ReO2·nH2O(s) and is accompanied by a decrease with the increase in NO3– concentration. Re(VII)/Tc(VII) reduction suffers from a serious interferential effect of NO3–, whereas the higher the concentration of NO3–, the more conducive to slowing down the reoxidation of the reduction products, which is advantageous for the subsequent sequestration or separation.
研究领域:
环境科学
·
放射化学
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Qun Wang,Han Zeng,Youheng Liang,Ye Cao,Yang Xiao,Jun Ma
The heterogeneous catalyst Mackinawite (FeS) was applied to activate periodate (IO 4 − ) to degrade endocrine disruptors bisphenol AF (BPAF). This study investigated the influence of FeS dosage, periodate dosage, BPAF concentration, initial pH value and inorganic ions on BPAF degradation by FeS/IO 4 − system. The results showed that the BPAF was effectively degraded by FeS/IO 4 − system. The acidic pH exhibited higher efficiency in BPAF degradation compared with alkaline and neutral conditions. Furthermore, the BPAF degradation was dramatically promoted in the presence of Cl − and SO 4 2− , whereas CO 3 2− inhibited BPAF degradation. The radical scavenging tests and EPR indicated that singlet oxygen ( 1 O 2 ), superoxide radicals (O 2 − ) and SO 4 − were committed to the degradation of BPAF, among which O 2 − , 1 O 2 were predominant radicals. The separate experiments showed that Fe(Ⅱ) participated in the activation of periodate. Furthermore, the effects of sulfur species (including the S 2− , SO 3 2− ) on BPAF degradation by FeS/IO 4 − system were studied. The radical quenching tests suggested that S 2− and SO 3 2− were responsible for producing SO 4 − . The findings of this study elucidated an approach for the removal of micro-pollutants in the water environment through heterogeneous activation of periodate by FeS.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Juan Liu,Wenju Weng,Chunxiao Yin,Guiling Luo,Hui Xie,Yanyan Niu,Xiaoyan Li,Guangjiu Li,Yaru Xi,Yutong Gong,Shuyao Zhang,Wei Sun
In this paper zinc-based metal organic framework material (ZIF-8) modified carbon ionic liquid electrode (CILE) was prepared and electrodeposited with gold nanoparticles to get a composite modified electrode, which was used as the sensing interface for the immobilization of hemoglobin (Hb) with Nafion to prepare a modified electrode (Nafion/Hb/Au/ZIF-8/CILE). Electrochemical behaviors of Hb on the modified electrode were checked by cyclic voltammetry with a pair of well-defined redox peaks appeared. The effects of pH and scan rate on direct electrochemistry of Hb were studied with electrochemical parameters calculated. The prepared electrochemical enzyme sensor showed good catalytic activity to the electroreduction of bromate and nitrite with the linear ranges from 0.5 to 10.0 mmol/L and from 0.1 to 0.8 mmol/L, respectively. The detection limits were calculated as 0.83 mmol/L and 0.03 mmol/L, and the water samples were analyzed to prove the practical application.
研究领域:
生物化学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Water Process Engineering
·
2025
·
IF 6.7
Haoran Xv,Qian Zhang,Thiquynhxuan Le,Duclenh Phan,Libo Zhang
Ammonium persulfate has been proven to be effective in purifying thiosulfate (S 2 O 3 2− ) and sulfite (SO 3 2− ) impurities in desulfurization solutions. However, the sole use of ammonium persulfate as an oxidant faces the challenge of high oxidant consumption. In this study, a novel approach was proposed to enhance the oxidation efficiency of ammonium persulfate on sulfur-containing ions through ultrasonic activation. The results indicate that this technology has the advantages of high purification efficiency and low usage of ammonium persulfate. Specifically, the concentrations of S 2 O 3 2− and SO 3 2− decreased from 16.26 g/L and 38.30 g/L to 1.09 g/L and 8.89 g/L, respectively, meeting the actual production requirements; and the usage of ammonium persulfate could be reduced by 10–30 g per liter of solution compared with the case of ammonium persulfate alone. The introduction of ultrasound increased the generation of free radicals (SO 4 · − and ·OH), enhancing their oxidative capacity. The contribution of free radicals to the oxidation of S₂O₃ 2− and SO₃ 2− increased from 11.1 % and 9.8 % to 50.0 % and 25.8 %, respectively. This study reveals that the ultrasonic activated ammonium persulfate is expected to achieve efficient purification of the desulfurization mother liquor and reduce the addition of ammonium persulfate.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Environmental Pollutants and Bioavailability
·
2019
·
IF 0
Xiaona Li,Yang Song,Yongrong Bian,Fang Wang,Chenggang Gu,Xinglun Yang,Xin Jiang
The effect of oxalic acid on phenanthrene sorption was varied from that on pyrene sorption. 1.0 mg L-1 of oxalic acid inhibited phenanthrene sorption, whereas 20, 50 and 100 mg L-1 of oxalic acid enhanced the sorption. However, pyrene sorption onto biochar was all inhibited among different concentrations of oxalic acid. New functional groups and increased polarity were observed in the biochar coexisted with oxalic acid, moreover, a high concentration of oxalic acid led to an increased specific surface area of the biochar. These changed factors contributed to biochar sorption to phenanthrene, which was dominated by surface adsorption. Weakened aromaticity and increased release of dissolved organic carbon from biochar may have been the main reason for inhibited pyrene sorption onto biochar by oxalic acid. Therefore, this study suggested that root exudates could greatly influence the sorption behavior of biochar towards PAHs in soil rhizosphere, which deserves attention in agricultural systems.
研究领域:
环境科学
·
农业科学
✓ 已验证
产品关联
DOI
Catalysts
·
2022
·Vol. 12
·期 10
·1207
·
IF 4.501
Chenliu Tang,Zhicheng Long,Yidan Wang,Dongze Ma,Xiaobiao Zhu
This study investigated the inhibition effects of sulfate on ferrous ion-activated persulfate oxidation of azo dye reactive brilliant red X-3B. The experimental results showed that the degradation efficiency of reactive brilliant red X-3B decreased from 100% to 63% in 60 min when the initial concentration of sulfate increased from 0 to 3 g/L. The ferrous/persulfate molar ratio had remarkable influence on persulfate oxidation capability in presence of sulfate. SO42−could coordinate with Fe2+and Fe3+in generating FeSO4ion pairs as well as FeSO4+or Fe(SO4)2−complexes, which were difficult to activate persulfate and reduced the regeneration of Fe2+. Radicals quenching and electron paramagnetic resonance experiments showed that ·OH and SO4·−were responsible for the oxidation of reactive brilliant red X-3B; however, the addition of sulfate significantly inhibited the generation of SO4·−, and then the generation of ·OH. Moreover, the corresponding Nernst equation indicated that high concentration of sulfate reduced the oxidation potential of SO4·−/SO42−. Experimental results proved that the adverse effects of sulfate on the persulfate oxidation could be counteracted either by batch addition of ferrous or by adding Ba2+to remove SO42−in the system.Keywords:persulfate;sulfate;sulfate radicals;reactive brilliant red X-3B
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
PLANT CELL AND ENVIRONMENT
·
2025
·
IF 6.3
Hongcheng Zhao,Jiarui Xu,Lin Huang,Yizhe Ding,Xianyong Lin,Chengliang Sun
Beneficial microbiomes significantly modulate root hair morphogenesis, yet the underlying signalling pathways remain unclear. Through comprehensive phenotypic analysis, we demonstrated that Azospirillum brasilense , a well-known plant-growth-promoting rhizobacteria (PGPR), promotes root hair development by prolonging the elongation period. The promotion of root hair growth by A. brasilense is attributed to increased auxin accumulation in root apices and enhanced shootward transport from the root tip, which is mediated by the accumulation of the auxin importer auxin transporter protein 1 (AUX1) in the lateral root cap and the overlying epidermis. Chemical or genetic disruption of auxin signalling abolished bacteria-induced root hair responses. Furthermore, A. brasilense upregulated several root hair-related basic helix-loop-helix family transcription factors, including root hair defective 6 (RHD6) and RHD6-LIKE 1 (RSL1), which control root hair development through RSL4. Morphological analysis revealed that while the rsl2rsl4 double mutant remained hairless after inoculation, A. brasilense successfully rescued root hair growth in rhd6rsl1 . These findings suggest that A. brasilense can bypass RHD6 to activate RSL4, which then drives root hair development dependent on ROS. Collectively, our study uncovers the core signalling components modulated by A. brasilense to fine-tune root hair responses.
研究领域:
植物生物学
·
微生物学
·
发育生物学
·
分子信号传导
·
根际细菌-植物互作
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）