Frontiers in Plant Science
·
2019
·
IF 4.106
Zhang Qiang,Liu Xiaofei,Zhang Zhifei,Liu Ningfang,Li Danzhu,Hu Longxing
Melatonin (MT), polyamines (PAs), and ethylene have been suggested to play key roles in plant growth and development in response to environmental abiotic stresses. However, the effect of melatonin on polyamine and ethylene metabolism under waterlogging stress has rarely been elucidated. The main purpose of this study was to investigate the effect of melatonin pretreatment on waterlogging stress in alfalfa. The experiment was arranged into four treatment groups control with water pretreatment (CK-MT), control with melatonin pretreatment (CK+MT), waterlogging pretreated with water (WL-MT) and waterlogging pretreated with melatonin (WL+MT), with three replications. Six-week-old alfalfa seedlings were pretreated with 100 μM melatonin and exposed to waterlogging stress for 10 days. Plant growth rate, different physiological characteristics, and gene expression level were measured. Results showed that waterlogging induced melatonin accumulation, and melatonin pretreatment increased endogenous MT levels for the control and water-logged plants. Waterlogging stress caused a significant reduction in plant growth, chlorophyll content, photochemical efficiency (Fv/Fm) and net photosynthetic rate (Pn), while also causing increased leaf electrolyte leakage (EL) and malondialdehyde (MDA) content. Pretreatment with melatonin alleviated the waterlogging-induced damage and reduction in plant growth, chlorophyll content, Fv/Fm and Pn. Waterlogging stress significantly increased leaf polyamines (Put, Spd, Spm) and ethylene levels, and the increased PAs and ethylene levels are coupled with higher metabolic enzymes and gene expressions. While pretreatment with melatonin further increased Put, Spd and Spm levels, it also decreased ethylene levels under waterlogging, and those increased PAs levels or decreased ethylene levels are regulated by the metabolic enzymes and gene expressions. The results in this study provide more comprehensive insight into the physiological and molecular mechanisms of melatonin-improved waterlogging tolerance in alfalfa. Furthermore, they suggested that melatonin improved waterlogging tolerance in alfalfa at least partially by reprogramming ethylene and PA biosynthesis, attributable to the increased PAs and decreased ethylene levels, which leads to more enhanced membrane stability and photosynthesis as well as less leaf senescence caused by ethylene.
研究领域:
植物生理学
·
分子生物学
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DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2023
·
IF 6.1
Wenjing Liu,Xiaoxiang Hu,Linghao Fang,Yujie Cai
Spermidine is a naturally occurring polyamine with multiple biological activities and potential food and agricultural applications. However, sustainable and scalable spermidine production has not yet been attained. In this study, a homospermidine synthase (HSS) from Pseudomonas frederiksbergensis (PfHSS) capable of catalyzing the synthesis of spermidine from 1,3-diaminopropane and putrescine was identified based on multiple sequence alignment using Blastochloris viridis HSS (BvHSS) as a template. The optimal reaction pH and temperature for purified PfHSS were determined to be 8.5 and 45 °C, respectively, and K+ was able to promote the enzyme activity. Further analysis of the structural and functional relationships through molecular docking and molecular dynamics simulation indicates that glutamic acid at position 359 is the essential residue for the enzyme-catalyzed synthesis of spermidine. The whole-cell catalytic reaction yielded 1321.4 mg/L spermidine and 678.2 mg/L of homospermidine. This study presents a novel, promising, and sustainable biological method for producing spermidine.
研究领域:
生物化学
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合成生物学
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食品科学
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农业科学
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DOI
PubMed
高影响因子
TALANTA
·
2020
·
IF 5.339
Zhang-Na Qin,Qiong-Wei Yu,Ping Zhou,Yu-Qi Feng
Bioactive polyamines play important roles in many biological processes such as gene expression, cell growth, protein synthesis , and signal transduction . Accurate determination of polyamines is helpful for studying their biological functions. Herein, a C 60 -based chemical labeling strategy was proposed for the determination of polyamines (putrescine, cadaverine , spermidine , and spermine) in biological samples using matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). An N-hydroxysuccinimide ester functionalized C 60 (NHS–C 60 ) was used as a labeling reagent and the m/z of the labeled polyamines reached up to more than 900 Da, which avoided matrix interferences in the low m/z region. In addition, as NHS–C 60 derivatives, mono- and bis-substituted polyamines were produced simultaneously, which benefited the qualitative analysis of polyamines. The analytical method was validated using NHS–C 60 labeled polyamines in cells and mice feces samples. Good linearities were obtained with correlation coefficients ranging from 0.9786 to 0.9982. The limits of quantification were in the range of 0.68–1.48 pmol. Good reproducibility and reliability of our proposed method were confirmed by intra- and inter-day precisions ranged from 2.8 to 16.6%, and the recoveries ranged between 81.8 and 119.9%. Finally, the proposed method was applied to determine polyamines in cells and mice feces. Three polyamines were detected in the cells, and the contents of cadaverine and spermidine in the feces of high-fat diet mice were found to be significantly lower than those in the normal diet mice. The results show that the proposed NHS–C 60 labeling coupled with MALDI MS strategy is suitable for the determination of polyamines in biological samples.
研究领域:
分析化学
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生物化学
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医学
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产品关联
DOI
PubMed
高影响因子
BIOTECHNOLOGY AND APPLIED BIOCHEMISTRY
·
2024
·
IF 3.2
Qian Tan,Linbo Gou,Tai-Ping Fan,Yujie Cai
Clostridium aceticum DSM1496 is an acid-resistant strain in which ornithine decarboxylase (ODC) plays a crucial role in acid resistance. In this study, we expressed ODC derived from C. aceticum DSM1496 in Escherichia coli BL21 (DE3) and thoroughly examined its enzymatic properties. The enzyme has a molecular weight of 55.27 kDa and uses pyridoxal-5′-phosphate (PLP) as a coenzyme with a K m = 0.31 mM. ODC exhibits optimal activity at pH 7.5, and it maintains high stability even at pH 4.5. The peak reaction temperature for ODC is 30°C. Besides, it can be influenced by certain metal ions such as Mn 2+ . Although l -ornithine serves as the preferred substrate for ODC, the enzyme also decarboxylates l -arginine and l -lysine simultaneously. The results indicate that ODC derived from C. aceticum DSM1496 exhibits the ability to produce putrescine, cadaverine, and agmatine through decarboxylation. These polyamines have the potential to neutralize acid in an acidic environment, facilitating the growth of microorganisms. These significant findings provide a strong basis for further investigation into the acid-resistant mechanisms contributed by ODC.
研究领域:
微生物学
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生物化学
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产品关联
DOI
PubMed
高影响因子
Membranes
·
2022
·Vol. 12
·期 11
·1151
·
IF 4.562
Jiawen Wu,Zhiwen Li,Qingfeng Zhou,Mercy Chigwidi,Yang Jiao,Yanchao Xu,Hongjun Lin
The co-deposition between polyphenols and amines has been demonstrated in order to prepare positively charged nanofiltration (NF) membranes for multivalent cation rejection in recent years; however, the low reactivities of the involved polyphenols usually cause a long co-deposition time and unsatisfactory rejection. Herein, a novel plant polyphenol (PG) was co-deposited with tetraethylenepentamine (TEPA) in a much shorter time period to prepare positively charged NF with high multivalent cation rejection membranes. The performance of the co-deposition membranes can be easily controlled by adjusting the mass ratio of PG and TEPA, reaction time, and pH value of the buffer solution. The optimal membrane, prepared under a polyphenol and polyamine mass ratio of 1:1, coating time of 2 h, and pH value of 8.0, shows a decent pure water permeability of 8.43 L m−2h−1bar−1while maintaining a superior 96.24% MgCl2rejection. More importantly, the universality of this method was corroborated by employing other amines with different molecular weights in the co-deposition. This work provides new insights for the preparation of high-performance positively charged NF membranes.
研究领域:
材料科学
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环境工程
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化学工程
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DOI
高影响因子
ACS Applied Materials & Interfaces
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2019
·
IF 8.456
Ziyi Cai,Jiafu Shi,Weiran Li,Yizhou Wu,Yishan Zhang,Shaohua Zhang,Zhongyi Jiang
Enclosed films, also called capsules, bearing an ultrathin and robust nanoshell have sparked much interest for use in many applications, for which facile preparation methods are urgently pursued. Inspired by the pH-programmed adhesion/cohesion of mussel-secreted foot proteins, polyphenol/polyamine capsules with an ultrathin and robust nanoshell are fabricated through a pH-switched assembly on sacrificial calcium carbonate (CaCO3) templates. Polyphenols adhere to the templates at pH 6.0 and rapidly cohere with polyamines at pH 8.0. The pH-switched assembly process is accomplished in only a few minutes where multiple instances of electrostatic interactions and chemical conjugation between polyphenols and polyamines occur. As a result, the capsules exhibit a nanoshell thickness of ∼10 nm and a superior mechanical strength of ∼1.575 GPa (elasticity modulus). Cell mimics are prepared through encasing enzymes in the lumen and present an activity recovery of ∼70% along with little activity decline during reuse. Amine or phenolic groups on the nanoshell of capsules are then applied to induce the generation of titania or silver nanoparticles, which may expand the applications of the capsules to the photo- and biorelated realms. Our study not only deepens the understanding of the adhering process of mussels but also offers a generic method toward functional materials for diverse applications.
研究领域:
材料科学
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生物化学
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仿生学
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DOI
高影响因子
PHYTOPATHOLOGY
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2024
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IF 2.6
Sun Qifang,Yingbin Hao,Yongquan Liu,Meng Cui,Zhang Gaowei,Yu Wenjie,Liping Luo
Citrus Huanglongbing, one of the most devastating citrus diseases, is caused by Candidatus Liberibacter asiaticus (CLas). Polyamines are aliphatic nitrogen-containing compounds that play important roles in disease resistance. However, the role of polyamine metabolism in the tolerance of citrus to infection with CLas have not been extensively studied. We used HPLC and UPLC-Q/TOF-MS to detect the contents of nine polyamine metabolism-related compounds (PMRCs) in six citrus cultivars with varying levels of tolerance to CLas. Moreover, we systematically detected the changes of PMRC and H2O2 contents, and compared the gene expression levels and activities of enzymes involved in the polyamine metabolic pathway among healthy, asymptomatic, and symptomatic leaves of Newhall navel oranges infected with CLas. The tolerant and moderately tolerant varieties showed higher PMRC levels than those of susceptible varieties. Compared with the healthy group, the symptomatic group showed significantly increased contents of arginine, ornithine, γ-aminobutyric acid, and putrescine by approximately 180, 19, 1.5, and 0.2 times, respectively, and up-regulated expression of biosynthetic genes. Arginase and ornithine decarboxylase enzyme activities were the highest in the symptomatic group, while arginine decarboxylase and agmatine deiminase enzyme activities were the highest in the asymptomatic group. The two polyamine biosynthetic pathways showed different trends with the increase of the titer of CLas, indicating that polyamines were mainly synthesized through the arginine decarboxylase pathway in the asymptomatic leaves, and were synthesized via the ornithine decarboxylase pathway in symptomatic leaves. These findings provide new insight into the changes of polyamine metabolism in citrus infected with CLas.
研究领域:
植物学
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分子生物学
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DOI
PubMed
高影响因子
DALTON TRANSACTIONS
·
2016
·Vol. 45
·期 13
·5484-5491
·
IF 4.177
Bo Li,Xudong Wang,Yali Guo,Anam Iqbal,Yaping Dong,Wu Li,Weisheng Liu,Wenwu Qin,Shizhen Chen,Xin Zhou,Yunhuang Yang
A one-step hydrothermal method was developed to fabricate Fe3O4–carbon dots (Fe3O4–CDs) magnetic–fluorescent hybrid nanoparticles (NPs). Ferric ammonium citrate (FAC) was used as a cheap and nontoxic iron precursor and as the carbon source. Moreover, triethylenetetramine (TETA) was used to improve the adhesive strength of CDs on Fe3O4 and the fluorescence intensity of CDs. The prepared water-soluble hybrid NPs not only exhibit excellent superparamagnetic properties (Ms = 56.8 emu g−1), but also demonstrate excitation-independent photoluminescence for down-conversion and up-conversion at 445 nm. Moreover, the prepared water-soluble Fe3O4–CDs hybrid NPs have a dual modal imaging ability for both magnetic resonance imaging (MRI) and fluorescence imaging.
研究领域:
材料科学
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医学影像
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纳米技术
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2023
·
IF 9.5
Li Zhang,Nanxi Di,Zhi Wang,Song Zhao
Nanofiltration (NF) has the potential to achieve the efficient effluent separation. However, conventional polyamide-based NF membranes face several challenging issues, including negatively charged surface, insufficient water permeance and low selectivity of organic micropollutants. Herein, we designed a novel polyamine membrane generated from the nucleophilic substitution reaction between 1,4,7,10-tetraazacyclododecane (Cyclen) and 1,3,5-tris(bromomethyl)benzene (TBB), and proposed its fabrication via oligomer triggered interfacial polymerization (OT-IP). As the crucial component of the polyamine membrane, the amine-linked Cyclen-TBB selective layer was assembled onto a porous substrate through interfacial polymerization between alkaline aqueous solution and organic solution consisting of Cyclen and TBB premixed in n-hexane. The resultant Cyclen-TBB composite membrane possessed an effective pore size of ∼1.6 nm and strongly positively charged surface with a zeta potential of +18.4 mV in a neutral solution. Owing to these characteristics, the Cyclen-TBB composite membrane exhibited a high water permeance of 77.0 L·m −2 ·h −1 ·bar −1 , and high rejections to positively charged dyes and drugs with molecular weights above 500 Da. Moreover, the composite membrane possessed splendid chemical resistance under both acidic or alkaline conditions, and operational stability during continuous filtration. These results demonstrate that novel highly permeable and positively-charged polyamine NF membranes are potential candidates for selective separation of molecules, and provide a feasible alternative for application in the treatment of industrial and pharmaceutical effluents.
研究领域:
材料科学
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环境工程
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化学工程
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产品关联
DOI
高影响因子
ACS Omega
·
2020
·
IF 2.87
Yanxue Gu,Yucui Hou,Shuhang Ren,Ying Sun,Weize Wu
CO2 emission from flue gas is an important issue threatening human survival. Deep eutectic solvents (DESs), which have many unique properties, have been studied for CO2 capture. However, water can be absorbed by DESs during the absorption of CO2, which may increase the energy cost during the desorption of CO2. In this work, a new kind of hydrophobic functional DES formed by polyamine hydrochloride and thymol was synthesized and used for CO2 capture. It had been found that these DESs could efficiently capture CO2 even at low partial pressures. The CO2 capacity of [TEPA]Cl-thymol (n[TEPA]Cl/nthymol = 1:3) was high up to 1.355 mol CO2/mol DES at 40 °C and 101.3 kPa. Interestingly, these DESs were still hydrophobic after saturated with CO2. The CO2 absorption capacity increased with a decrease of temperature and an increase of CO2 partial pressure. Regeneration results showed that no obvious loss in the capacity could be found after five absorption/desorption cycles of these DESs. The Fourier transform infrared (FT-IR) spectra indicated that CO2 could interact with amino in the DESs by the formation of carboxylate. Moreover, the equilibrium constant and Henry’s law constant in chemical absorption and physical absorption were studied.
研究领域:
化学工程
·
环境科学
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产品关联
DOI
PubMed
高影响因子
Science China-Technological Sciences
·
2021
·Vol. 64
·期 10
·2211-2219
·
IF 3.572
Cai YaHui,Chen DongYun,Li NaJun,Xu QingFeng,Li Hua,He JingHui,Lu JianMei
The efficient and rapid separation of oil from stabilized oil-in-water emulsions with micro/nanometer size is a global challenge. Owing to the low oil content in oil-in-water emulsions, separating the oil by simply controlling the surface wettability is difficult. Controlling the pore size of the membrane surface to achieve separation will lead to a sharp decrease in flux. Herein, inspired by cell membrane transportation, a hydrophilic/hydrophobic bifunctional Janus membrane for stable oil-in-water separation was prepared by simple surface polymerization and vapor diffusion. The prepared Janus membrane contained a hydrophobic side and hydrophilic polyamine layer. When used for oil-in-water emulsion separation, the polyamine layer accumulated micro/nanometer oil droplets, forming an oil layer on the hydrophobic surface. Water was retained by the 1 H ,1 H ,2 H ,2 H -perfluorooctyl trichlorosilane layer, allowing oil droplets to selectively permeate through the membrane, achieving the separation effect. As the pore size of the modified fabric was basically unchanged, the permeation flux was fast (1.53×10 3 Lm −2 h −1 ). Furthermore, the poly( N,N -dimethylaminoethyl methacrylate) layer destroyed the emulsion stability, making the emulsion droplets aggregate without affecting the separation efficiency with fast permeation flux. Therefore, the prepared bifunctional Janus membrane shows great potential for actual wastewater treatment.
研究领域:
材料科学
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环境工程
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产品关联
DOI
高影响因子
CARBON
·
2017
·
IF 6.337
Xiaoyan Pei,Dazhen Xiong,Jing Fan,Zhiyong Li,Huiyong Wang,Jianji Wang
In recent years, carbon nanodots (CDs) have attracted increasing attention in many applications because of their superior optical and chemical properties. To manipulate CDs properties for their smart applications, CDs with CO 2 switchable luminescence property have been designed and prepared in the present work. It is found that fluorescence of the polyamine-functionalized CDs can be switched “off” and “on” in DMSO-water mixture by alternatively bubbling and removal of CO 2 . 13 C NMR spectra suggest that the mechanism behind the fluorescence “on-off” results involves the reversible acid-base reaction of the functionalized CDs with CO 2 and the formation of hydrophilic polyammonium bicarbonates. Due to the poor solubility of polyammonium bicarbonates in DMSO-water mixture, the formation of the polyammonium bicarbonates precipitation, by CO 2 bubbling, decreases the concentration of the functionalized CDs in aqueous DMSO, leading to the switch off of the fluorescence. When CO 2 is removed by N 2 bubbling, the precipitation is returned to the DMSO-water mixture, and thereby the fluorescence is switched on again. Based on this novel CO 2 -switchable photoluminescence property, the functionalized CDs have been used for the quantitative detection of CO 2 and SO 2 in aqueous solution and in the air.
研究领域:
材料科学
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化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）