Phosphatidylethanolamine N-methyltransferase and choline dehydrogenase gene polymorphisms are associated with human sperm concentration

Choline is a crucial factor in the regulation of sperm membrane structure and fluidity, and this nutrient plays an important role in the maturation and fertilizing capacity of spermatozoa. Transcripts of phosphatidylethanolamine N-methyltransferase （PEMT） and choline dehydrogenase （CHDH）, two basic enzymes of choline metabolism, have been observed in the human testis, demonstrating their gene expression in this tissue. In the present study, we explored the contribution of the PEMTand CHDHgene variants to sperm parameters. Two hundred oligospermic and 250 normozoospermic men were recruited. DNA was extracted from the spermatozoa, and the PEMT -774G〉C and CHDH ＋432G〉T polymorphisms were genotyped. The genotype distribution of the PEMT-774G〉C polymorphism did not differ between oligospermic and normozoospermic men. In contrast, in the case of the CHDH ＋432G〉T polymorphism, oligospermic men presented the CHDH432GIG genotype more frequently than normozoospermic men （62% vs. 42%, P〈0.001）. The PEMT774GIG genotype was associated with a higher sperm concentration compared to the PEMT774GIC and 774C/C genotypes in oligospermic men （12.5±5.6× 10^6 spermatozoa m1-1 vs. 8.3±5.2×10^6 spermatozoa m1-1, P〈0.002） and normozoospermic men （81.5±55.6×10^6 vs. 68.1±44.5×10^6 spermatozoa m1-1, P〈0.006）. In addition, the CHDH432G/G genotype was associated with higher sperm concentration compared to CHDH432G.T and 432T/T genotypes in oligospermic （11.8±5.1×10^6 vs. 7.8±5.3×10^6 spermatozoa m1-1, P〈0.003） and normozoospermic men （98.6±62.2×10^6 vs. 58.8±＋33.6×10^6 spermatozoa m1-1, P〉0.001）. In our series, the PEMT-774G〈C and CHDH ＋432G〈T polymorphisms were associated with sperm concentration. This finding suggests a possible influence of these genes on sperm quality.

Severity of ulcerative colitis is associated with a polymorphism at diamine oxidase gene but not at histamine N-methyltransferase gene

AIM： To analyse the role of two common polymorphisms in genes coding for histamine metabolising enzymes as it relates to the risk to develop ulcerative colitis （UC） and the clinical course of these patients. METHODS： A cohort of 229 unrelated patients with UC recruited from a single centre and 261 healthy volunteers were analysed for the presence of Thr105Ile and His645Asp amino acid substitutions at histamine N-methyltransferase （HNMT） and diamine oxidase （ABP1） enzymes, respectively, by amplification-restriction procedures. All patients were phenotyped and followed up for at least 2 years （mean time 11 years）. RESULTS： There were no significant differences in the distribution of ABP1 alleles between ulcerative colitis patients and healthy individuals [OR （95% CI） for variant alleles = 1.22 （0.91-1.61）]. However, mutated ABP1 alleles were present with higher frequency among the 58 patients that required immunosuppresive drugs [OR （95 % CI） for carriers of mutated alleles 2.41 （1.21-4.83; P=0.006）], with a significant gene-dose effect （P= 0.0038）. In agreement with the predominant role of ABP1 versus HNMT on local histamine metabolism in human bowel, the frequencies for carriers of HNMT genotypes or mutated alleles were similar among patients,regardless clinical evolution, and control individuals. CONCLUSION： The His645Asp polymorphism of the histamine metabolising enzyme ABP1 is related to severity of ulcerative colitis.

A Comparative Study About the Neuroprotective Effects of EPA-Enriched Phosphoethanolamine Plasmalogen and Phosphatidylethanolamine Against Oxidative Damage in Primary Hippocampal Neurons

s Oxidative stress is involved in the progression of neurodegenerative diseases.Previous evidences showed that plasma-logens could improve neurodegenerative diseases.In this study,we investigated the function of phosphoethanolamine plasmalogens enriched with EPA(EPA-pPE)and phosphatidylethanolamine enriched with EPA(EPA-PE)on oxidative damage prevention after hy-drogen peroxide(H2O2)and tert-butylhydroperoxide(t-BHP)challenge in primary hippocampal neurons.Results showed that neurons pretreated with EPA-pPE and EPA-PE demonstrated the ability to alleviate oxidative damage,which was proved by the in-creased cell viability.Moreover,the shape and number of neurons were more similar to those of the control group.Antioxidant acti-vity,apoptosis,as well as TrkB/ERK/CREB signaling pathway were investigated to explore the mechanisms.The results suggested that EPA-PE was superior to EPA-pPE in regulating mitochondrial apoptosis.EPA-pPE was more prominent than EPA-PE in upre-gulating TrkB/ERK/CREB signaling pathway.Phospholipids with EPA exerted neuroprotective effects via inhibiting oxidative stress,suppressing apoptosis,and regulating TrkB/ERK/CREB signaling pathway.Therefore,the results provide a scientific basis for utili-zation of phospholipids enriched with EPA on the treatment of neurodegenerative disease.

Phosphomonoester Phosphoethanolamine Induces Apoptosis in Human Chronic Myeloid Leukemia Cells

Background:Leukemia is a type of cancer that starts in the blood or blood-forming tissues.It results from the clonal proliferation of hematopoietic cells in the bone marrow and/or lymphoid tissues,which subsequently reach the peripheral circulation and can infiltrate other systems.There are many different kinds of leukemia,and treatments are different for each one.Chronic leukemia is with a slower growing than acute leukemia but could be just as life-threatening.Phospholipids are antitumor analogs,such as synthetic phosphoethanolamine,which is a phosphorylated compound capable of controlling cellular proliferation and inducing apoptosis in several types of tumor cells.Methods:K562 and K562-Lucena(MDR+)human chronic myeloid leukemia cells were treated with synthetic phosphoethanolamine(Pho-s).The viability was evaluated by sulforhodamine B(SRB)assay and cell cycle phases,apoptosis,markers expression,and mitochondrial potential were assessed by flow cytometry.Results:Tumor cells formed clusters in suspension and decreased significantly viability.The concentrations for IC50%were obtained.Pho-s treated were 43.1 mM(K562)and 145.9 mM(K562-Lucena MDR+)in a period of 24 hours.Pho-s induced changes in the distribution of cell population phases of cell cycle which showed an increase in fragmented DNA and increased markers expression envolved apoptosis pathways a decrease in the G1/G0 phase.Discussion:Treatment of K562 and K562-Lucena(MDR+)chronic myeloid leukemia cells with Pho-s showed dose and time dependent cytotoxic effects.This cytotoxicity induced a decrease in proliferative capacity,mitochondrial electrical potential,and consequently release of cytochrome C;inhibition of Bcl-2 family protein expression,increase in pro-apoptotic family members Bad and Bax,dependent on p53 expression.Conclusion:This study presented a significant therapeutic potential of Phos-s in this type of leukemia through the apoptotic effects on tumor cells independently of the molecular resistance profile(MDR+).

Meclizine Chloridrate and Methyl-β-Cyclodextrin Associated with Monophosphoester Synthetic Phosphoethanolamine Modulating Proliferative Potential in Triple-Negative Breast Cancer Cells

Synthetic phosphoethanolamine(Pho-s)is a monophosphoester ester with anti-inflammatory and pro-apoptotic properties.Meclizine chloridrate(MC)is a histamine H1 receptor blocker that is also able to inhibit cellular respiration.However,MC does not inhibit cellular respiration in isolated mitochondria such as antimycin and rotenone.Methyl-β-cyclodextrin(MβCD)belongs to theβ-cyclodextrin family,which is capable of removing cholesterol from the plasma membrane.The aim of this study was to evaluate the proliferative effects of meclizine chloridrate and methyl-β-cyclodextrin compounds associated with synthetic phosphoethanolamine in a triple-negative human breast tumor line,MDA-MB-231 Cell viability of the tumor line and normal cells FN1 was evaluated by MTT colorimetric test;the production of free radicals was determined by lipoperoxidation(LPO)test;and the percentage of cell cycle phases and proliferative index was evaluated by flow cytometry.Cell viability demonstrated a significant decrease with the treatments of MβCD,MC and Pho-s associated with MC.The production of free radicals decreases significantly in all treatments.In addition,a significant increase of DNA fragment and decrease in G0/G1 cell cycle phase were observed in cellular percentage with concentrations of 20 and 30 mM of Pho-s in association with MC and MβCD,respectively.

DSPE-mPEG2000修饰荷叶碱脂质体制备及其体内药动学研究

目的制备二硬脂酰磷脂酰乙醇胺-聚乙二醇2000(DSPE-mPEG2000)修饰荷叶碱脂质体,并考察其体内药动学。方法薄膜超声法制备脂质体。以磷脂酰胆碱与胆固醇比例、脂药比、DSPE-mPEG2000用量、水化温度、超声时间为影响因素,单因素试验优化处方,测定包封率、载药量、粒径、PDI、Zeta电位、体外释药。18只大鼠随机分为3组,分别灌胃给予荷叶碱原料药、不含DSPE-mPEG2000荷叶碱脂质体、DSPE-mPEG2000修饰荷叶碱脂质体的0.5%CMC-Na混悬液(20 mg/kg),于0、0.25、0.5、1、1.5、2、3、4、6、8、12 h采血,HPLC-MS/MS法测定荷叶碱血药浓度,计算主要药动学参数。结果最佳处方为荷叶碱用量20 mg,磷脂酰胆碱与胆固醇比例5∶1,脂药比12∶1,DSPE-mPEG2000用量30 mg,水化温度40℃,超声时间15 min,平均包封率为71.69%,载药量为4.59%,粒径为161.84 nm,PDI为0.163,Zeta电位为-7.17 mV。DSPE-mPEG2000修饰后,荷叶碱在人工胃液、人工肠液中48 h内累积释放度分别为66.17%、53.90%。与原料药比较,脂质体t_(max)、t_(1/2)延长(P<0.01),C_(max)、AUC_(0~t)、AUC_(0~∞)升高(P<0.01),相对生物利用度增加至6.14倍。结论DSPE-mPEG2000修饰脂质体可促进荷叶碱口服吸收。

Nicotinamide N-methyltransferase and liver diseases

Cellular metabolism-induced epigenetic regulation is essential for the maintenance of cellular homeostasis.Nicotinamide N-methyltransferase(NNMT)is emerging as a key point of intersection between cellular metabolism and epigenetic regulation and has a central role in various physiological and pathological processes.NNMT catalyzes the methylation of nicotinamide(NAM)using the universal methyl donor S-adenosyl methionine(SAM)to yield S-adeno-syl-L-homocysteine(SAH)and N1-methylnicotinamide(MNAM),directly linking methylation balance with nicotinamide adenosine dinucleotide(NAD+)contents.NNMT acts on either the SAM-methylation balance or both NAD+metabolism,depending on the tissue involved or pathological settings where metabolic demand is increased.Under physiological conditions,the liver act as an essential metabolic organ with abundant NNMT expression,while NNMT hepatic function is not mediated by its methyltransferase activity due to other major methyltransferases such as glycine N-methyltransferase(GNMT)in the liver.However,hepatic NNMT,as well as its metabolite is improperly regulated and linked to the worse pathological states in liver diseases,including alcoholic liver disease,non-alcoholic fatty liver disease(NAFLD),liver cirrhosis,and hepatocellular carcinoma(HCC),suggesting a potential role in the process of liver diseases.In this review,we summarize how NNMT regulates cell methylation balance and NAD metabolism,and extensively outline the current knowledge concerning the functions of NNMT in hepatic metabolism including glucose,lipid and energy,with a specific focus on the contribution of NNMT to the pathophysiology of liver-related diseases.NNMT is involved in the development and progression of liver diseases.Understanding the complex NNMT regulatory network and its effects on pathogenesis could provide new therapeutic strategies in the context of liver diseases.

枸杞胆碱合成关键酶基因PEAMT的克隆及生物信息学分析

利用RT-PCR和RACE结合的方法,获得了枸杞磷酸乙醇胺N-甲基转移酶PEAMT基因cDNA全序列(命名为LbPEAMT)。LbPEAMTcDNA全长1 863bp,开放读码框1 497bp,编码一个由498个氨基酸构成的多肽,理论分子量为56.53kDa,等电点pI为5.50。通过多种序列比对,该基因编码的氨基酸序列与番茄PEAMT氨基酸的相似性为93%。二级结构预测LbPEAMT蛋白由44.98%的α-螺旋、17.67%的延伸链、6.63%的β-转角和30.72%的不规则卷曲组成。LbPEAMT是一个亲水蛋白。含有2个S-腺苷甲硫氨酸依赖催化活性结构域,分别位于N端65-164aa和C端290-392aa。每个活性区都包含有4个部分基序,分别为I、post I、post II和post III。LbPEAMT的这2个活性区在蛋白、磷脂和小分子甲基转移酶中都是相对保守的。

盐穗木HcPEAMT基因的克隆及表达分析

依据盐穗木编码PEAMT的EST序列设计引物,通过快速扩增cDNA末端技术,获得盐穗木磷酸乙醇胺甲基转移酶(phosphoethanolamine N-methyltransferase,PEAMT)全长cDNA,命名为HcPEAMT。序列分析表明HcPEAMT基因开放阅读框为1 482bp,编码494个氨基酸,推测分子量为56.3kD,理论等电点为5.51。保守结构域分析表明,HcPEAMT含有2个独立的S-腺苷甲硫氨酸依赖性甲基转移酶的保守结构域,每个结构域含有4个基序。系统进化树分析确认HcPEAMT与盐生植物盐角草的亲缘关系较近。实时荧光定量PCR分析表明,盐胁迫3h时,盐穗木同化枝和根中HcPEAMT基因的表达迅速上调并达到最大值,分别为对照的4.3倍和6.7倍。脱落酸(ABA)胁迫3h时,同化枝中HcPEAMT的表达量达到最高,而根中HcPEAMT的表达在12h才达到最高,表达量分别为对照的2.6和2.5倍。研究结果表明,HcPEAMT基因表达受盐胁迫的强烈诱导,也受ABA胁迫的诱导。该研究结果有助于阐明HcPEAMT基因表达与植物抗逆性的相关性。

无芒隐子草CsPEAMT基因克隆及表达特性分析

以无芒隐子草(Cleistogenes songorica)干旱胁迫下的cDNA文库中磷酸乙醇胺N-甲基转移酶(phosphoethanolamine N-methyltransferase,PEAMT)基因的EST序列为基础,采用RACE方法克隆该基因编码区序列,该序列全长为2 104bp,开放读码框1 506bp,编码501个氨基酸。无芒隐子草PEAMT蛋白编码的氨基酸序列与多种植物的PEAMT氨基酸序列有较高相似性,其中与高粱SbPEAMT、玉米ZmPEAMT的蛋白序列相似性最高(93%),说明PEAMT基因在植物进化中非常保守。采用实时定量RT-PCR分析无芒隐子草幼苗在干旱过程中CsPEAMT基因的表达结果显示,干旱胁迫诱导CsPEAMT基因在根和叶中大量表达,且在干旱第8天时CsPEAMT基因在叶和根中表达量分别是未干旱对照的43.35倍和13.25倍,复水后CsPEAMT基因的表达量开始下调。研究表明CsPEAMT基因可能是无芒隐子草抗旱性相关的基因。

干燥过程中LEA-motif蛋白特征重复片段对POPE膜结构的保护研究

通过分子动力学模拟的方法,模拟了1-棕榈酰基-2-油酰基磷脂酰乙醇胺(1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine,POPE)生物膜在添加胚胎发育晚期丰富蛋白(Late embryogenesis abundant proteins,LEA蛋白)特征重复片段(LEA-motif)前后两种体系在低温下的干燥过程,对比分析了干燥过程中两种体系在POPE生物膜结构、扩散系数、侧链有序性及分子间氢键数目的变化,从微观角度揭示了POPE生物膜因干燥失水导致的结构变化以及添加LEA-motif之后LEA-motif与POPE生物膜的相互作用.结果表明,LEAmotif在脱水干燥过程中能够有效地稳定膜的结构,从而保护生物材料的生物活性.

植物磷酸乙醇胺甲基转移酶的生物信息学分析

运用生物信息学的方法,对已在Genbank数据库中注册的菠菜、甜菜、拟南芥、陆地棉和辽宁碱蓬等中磷酸胆碱合成的关键酶磷酸乙醇胺甲基转移酶(PEAMT)的氨基酸序列进行分析。结果显示:植物PEAMT属于稳定蛋白质,含有较丰富的赖氨酸和亮氨酸;不同植物PEAMT的氨基酸序列具有较高的同源性,含有与SAM结合的保守结合域及Tyr-His氨基酸对;植物PEAMT属于胞质酶,不与膜结合;分子进化研究表明PEAMT可作为植物遗传分化和分子进化研究的重要依据;氨基酸序列中不存在信号肽;分子中不存在跨膜结构域,可能受蛋白激酶C的磷酸化;无规则卷曲是多肽链中的主要结构元件;蛋白质保守区域包含两个AdoMet-MTase区域,属于典型的SAM依赖性甲基转移酶功能结构域。本研究还初步构建了菠菜PEAMT的三维模型,能够认识植物中PEAMT的特异性及催化分子机制,并为通过分子改造创造出具有更强抗逆效能的PEAMT提供理论参考。

Wistar大鼠脑内各区的Salsolinol氮甲基转移酶活性检测

Parkinson’s disease is a common chronic neurodegenerative disease.N-methylation can enhance the neurotoxiicity to dopaminergic neuron in the metabolic process of catechol isoquinolines and Salsolinol N-methyltransferases (SNMT) may play an important role in the pathogenesis of PD.A new method including SNMT purification and detecting SNMT activity was developed and displays an excellent sensitivity and stability.In addition,the SNMT activity in Wistar rats substantia nigra,striatum and cerebellum.

盐角草磷酸乙醇胺N-甲基转移酶基因(SePEAMT)启动子的克隆及瞬时表达

磷酸胆碱是合成磷脂酰胆碱和甘氨酸甜菜碱的重要前体,磷酸乙醇胺N-甲基转移酶(PEAMT)是磷酸胆碱合成的关键酶。根据已知的SePEAMT cDNA5′端序列设计2个基因特异的反向引物(PP1,PP2),通过锚定PCR获得了PEAMT起始密码子上游1249bp的序列。RLM-RACE反应确定其转录起始位点A位于起始密码子上游301bp处,由此获得了948bp的SePEAMT启动子序列。PlantCARE和PLACE在线启动子预测工具分析表明:该序列除了含有启动子的基本元件TATA-box和CAAT-box外,还含有一些胁迫诱导元件(如ABRE、HSE、LTR)和花粉特异的激活元件AGAAA。构建了SePEAMT启动子与报告基因GUS融合的表达载体pPro,并通过农杆菌介导的叶盘法转化烟草,染色结果表明SePEAMT启动子可以有效地驱动GUS基因的瞬时表达。

牛血清蛋白对二硬脂酰基磷脂酰乙醇胺单层膜结构的影响

利用Langmuir-Blodgett(LB)技术结合原子力显微镜(AFM),研究了牛血清蛋白(BSA)在气/液界面上对二硬脂酰基磷脂酰乙醇胺(DSPE)单层膜结构的影响.通过改变亚相的pH值和BSA浓度,获得了不同条件下DSPE单层膜的等温线、吸附曲线和压缩循环曲线等.实验结果表明,亚相中BSA的存在对DSPE单层膜的压缩性、稳定性以及相变行为产生了较大的影响.吸附动力学结果表明,DSPE单层膜对BSA分子的吸附量存在一定的阈值,且该阈值的大小与亚相pH值相关.通过分析实验数据可知,当亚相pH=3时,BSA的疏水残基几乎全部暴露在外面,2种分子之间的相互作用最强;而pH=7时,BSA仅有少量的疏水残基暴露在外面,2种分子之间的相互作用最弱.原子力显微镜观测到的单层膜形态变化特点与曲线分析结果一致.该研究为了解牛血清蛋白与磷脂分子之间的相互作用机理提供了重要的实验基础和理论依据.

Nicotinamide N-methyltransferase protein expression in renal cell cancer

Objective: To understand the function of nicotinamide N-methyltransferase (NNMT) protein as tumor biomarker in renal carcinoma. Methods: Recombinant NNMT protein was used to prepare monoclonal antibodies by hybridoma technique. The diagnostic and prognostic function of NNMT protein in renal carcinoma was evaluated by analyzing 74 renal cancer tissues through immunohistochemical staining for NNMT by using the prepared antibodies. Results: Two hybridomas named 2F8 and 1E7 stably secreting the monoclonal antibodies were isolated successfully, and characters such as isotypes and specificity were determined. NNMT protein was significantly up-regulated in renal cancer and significantly associated with tumor histology and ages. The univariate survival analysis demonstrated that the pT-status, high levels of NNMT, and distant metastasis were significant prognosticators. Conclusion: NNMT is over-expressed in a large proportion in renal cell cancers. High NNMT expression is significantly associated with unfavorable prognosis. However, the prognostic value of NNMT needs further verification in larger sample sizes.

脂质体药用辅料mPEG2000-DSPE的合成

以氧氯化磷、乙醇胺及1,2-二硬脂酸甘油酯为原料,经环合、磷酰化及水解反应制得1,2-二硬脂酰甘油磷酰乙醇胺(DSPE);在N,N′-羰基二咪唑作用下,DSPE与甲氧基聚乙二醇(mPEG2000)反应合成了1,2-二硬脂酰甘油磷脂酰乙醇胺-N-甲氧基聚乙二醇2000(mPEG2000-DSPE),其结构经1 H NMR,IR和MS(ESI)确证。

磷酸乙醇胺转移酶MCR1结构与功能的研究

本实验克隆了来源于E.coli的MCR1基因酶催化结构域,以E.coli表达系统表达蛋白.采用亲和层析、阴离子交换层析、分子筛层析等纯化方法获得纯度高、均一性好的蛋白;采用座滴和悬滴法,获得酶催化区域的蛋白质晶体;收集X射线数据后,分子置换法解析出酶催化区域的结构,其分辨率达到1.63埃.反常散射信号检测到4个锌离子信号,结构分析锌离子与周围Thr285、His465、His466、His395位氨基酸联系紧密,且Thr285被磷酸化.Thr285、His465、His466和His395点突变为丙氨酸后,宿主菌粘菌素抗性显著降低,表明该区域与酶活密切相关.本实验解析出MCR1酶活性区域的结构,鉴定出酶活性中心,为寻找抗MCR1靶向药物提供可用信息.

Efficient biosynthesis of creatine by whole-cell catalysis from guanidinoacetic acid in Corynebacterium glutamicum

Creatine is a naturally occurring derivative of an amino acid commonly utilized in functional foods and pharmaceuticals.Nevertheless,the current industrial synthesis of creatine relies on chemical processes,which may hinder its utilization in certain applications.Therefore,a biological approach was devised that employs whole-cell biocatalysis in the bacterium Corynebacterium glutamicum,which is considered safe for use in food production,to produce safe-for-consumption creatine.The objective of this study was to identify a guanidinoacetate N-methyltransferase(GAMT)with superior catalytic activity for creatine production.Through employing whole-cell biocatalysis,a gamt gene from Mus caroli(Mcgamt)was cloned and expressed in C.glutamicum ATCC 13032,resulting in a creatine titer of 3.37 g/L.Additionally,the study employed a promoter screening strategy that utilized nine native strong promoters in C.glutamicum to enhance the expression level of GAMT.The highest titer was achieved using the P1676 promoter,reaching 4.14 g/L.The conditions of whole-cell biocatalysis were further optimized,resulting in a creatine titer of 5.42 g/L.This is the first report of successful secretory creatine expression in C.glutamicum,which provides a safer and eco-friendly approach for the industrial production of creatine.

Abscisic acid-dependent PMT1 expression regulates salt tolerance by alleviating abscisic acid-mediated reactive oxygen species production in Arabidopsis

Phosphocholine(PCho)is an intermediate metabolite of nonplastid plant membranes that is essential for salt tolerance.However,how PCho metabolism modulates response to salt stress remains unknown.Here,we characterize the role of phosphoethanolamine N-methyltransferase 1(PMT1)in salt stress tolerance in Arabidopsis thaliana using a T-DNA insertional mutant,geneediting alleles,and complemented lines.The pmt1 mutants showed a severe inhibition of root elongation when exposed to salt stress,but exogenous ChoCl or lecithin rescued this defect.pmt1 also displayed altered glycerolipid metabolism under salt stress,suggesting that glycerolipids contribute to salt tolerance.Moreover,pmt1 mutants exhibited altered reactive oxygen species(ROS)accumulation and distribution,reduced cell division activity,and disturbed auxin distribution in the primary root compared with wild-type seedlings.We show that PMT1 expression is induced by salt stress and relies on the abscisic acid(ABA)signaling pathway,as this induction was abolished in the aba2-1 and pyl112458 mutants.However,ABA aggravated the salt sensitivity of the pmt1 mutants by perturbing ROS distribution in the root tip.Taken together,we propose that PMT1 is an important phosphoethanolamine N-methyltransferase participating in root development of primary root elongation under salt stress conditions by balancing ROS production and distribution through ABA signaling.