毛细管液相色谱法分离植物内源激素

建立了毛细管液相色谱法(CLC)同时分离测定4种植物内源激素的方法.采用硅胶基质ODS整体柱(27 cm×100 μm i.d.)作为分离柱,以带有光程为3 mm的光纤检测池的紫外检测器作为检测手段,在室温下以含10 mmol/L乙酸(pH 3.0)的V(甲醇):V(水)＝35:65为流动相,以0.6 μL/min的流速进行等度洗脱.采用溶剂梯度效应和扩展光程的检测池来提高检测灵敏度,该方法测定4种植物内源激素的检出限(S/N=3)在27.7～196.1 ng/mL之间,峰面积和保留时间的相对标准偏差(RSD)小于2.8%.方法已用于不同种类玉米样品的测定.     

Turgorins,Hormones of the Endogeneous Daily Rhythms of Higher Organized Plants—Detection,Isolation, Structure,Synthesis, and Activity

Probably the most fascinating biological phenomenon is the movement which is so impressively observed in higher organized plants when, e.g., in a sort of “quick retreat”, the sensitive plant apparently vanishes on touching, or when all the pinnules of an acacia fold together pairwise at dusk, as though the whole tree were going to “sleep”. Such plants and trees do not possess muscles for the movement of their organs; instead of the contraction of a “still primitive” actomyosin system in this movement the hydrostatic internal pressure of the vacuoles—the turgor—in the parenchymal cells of the motile organs is often drastically and unilaterally reduced. After preception of an external stimulus there follows a gradual or sudden change in the semipermeability of the boundry plasma layers, and, mediated by a stimulus conduction, also of all the symplasts of a multicellular plant organism. The phytohormones which form the molecular basis of the physiology of movement discussed here have now been isolated and structurally elucidated. The chemical agonists of phytodynamics, referred to as turgorins, elicit leaf movement; moreover, they very probably also regulate—perhaps together with other phytohormones—the mechanism of change of aperture in stomatal transpiration. Hence, the turgorins facilitate not only a regulation of temperature, but even their own transport in the sap of the whole plant body.     

Simultaneous analysis of ten phytohormones in Sargassum horneri by high‐performance liquid chromatography with electrospray ionization tandem mass spectrometry

Phytohormones have attracted wide attention due to their important biological functions. However, their detection is still a challenge because of their complex composition, low abundance and diverse sources. In this study, a novel method of high‐performance liquid chromatography with electrospray ionization tandem mass spectrometry was developed and validated for the simultaneous determination of ten phytohormones including indole‐3‐acetic acid, isopentenyladenine, isopentenyl adenosine, trans‐zeatin riboside, zeatin, strigolactones, abscisic acid, salicylic acid, gibberellin A3, and jasmonic acid in Sargassum horneri (S. horneri). The phytohormones were extracted from freeze‐dried S. horneri with methanol/water/methanoic acid (15:4:1, v/v/v) analyzed on a Hypersil Gold C₁₈ column and detected by electrospray ionization tandem triple quadrupole mass spectrometry in the multiple reaction monitoring mode. The experimental conditions for the extraction and analysis of phytohormones were optimized and validated in terms of reproducibility, linearity, sensitivity, recovery, accuracy, and stability. Distributions of the phytohormones in the stems, blades, and gas bladder of the S. horneri in drift, fixed, and semi‐fixed growing states were investigated for the first time. The observed contents of the phytohormones in S. horneri range from not detected to 5066.67 ng/g (fresh weight). Most phytohormones are distributed mainly in the stems of S. horneri in drift and semi‐fixed states.     

Synthesis of novel mesoporous carbon nanoparticles and their phytotoxicity to rice (Oryza sativa L.)

Despite the remarkable number of investigations on the potential risks of the engineered nanomaterials (ENMs) to terrestrial plants, there was limited knowledge regarding the effects of mesoporous carbon nanoparticles (MCNs) with different sizes on crops. The objective of our study was to evaluate the toxicity of MCNs to rice (Oryza sativa L.) seedlings. Two novel MCNs with different particle sizes (MCN1: 150 and MCN2: 80?nm) were synthesized using the high-temperature pyrolysis method and characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy, and Raman spectra. Phytotoxicity of two MCNs was then comparatively evaluated using rice as a model plant. The rice seedlings were hydroponically exposed to both MCN suspensions with concentrations of 0, 10, 50, 150?mg/L for 20?days. Exposure to 150?mg/L MCN1 resulted in more than 21% and 29% decrease in root length and in shoot length, respectively. MCN2 significantly reduced the root and shoot lengths by approximately 70% and 57% at the concentration of 150?mg/L. Additionally, the concentrations of three endogenous phytohormones, including brassinolide (BR), indole propionic acid (IPA), and dihydrozeatinriboside (DHZR) in plant shoots were increased significantly compared with the control. Our findings illustrated that size-effects of MCNs contributed greatly in causing phytotoxicity to plants, which should have drawn our attention to the use of these novel ENMs in agriculture given the evidence of their potential risks to crops. More importantly, this is the first study on assessment of the phytotoxicity of MCNs to rice seedlings from the perspective of plant hormones.     

Simultaneous analysis of different classes of phytohormones in coconut (Cocos nucifera L.) water using high-performance liquid chromatography and liquid chromatography-tandem mass spectrometry after solid-phase extraction

Coconut (Cocos nucifera L.) water, which contains many uncharacterized phytohormones is extensively used as a growth promoting supplement in plant tissue culture. In this paper, a high-performance liquid chromatography (HPLC) method was developed for the simultaneous determination of various classes phytohormones, including indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), abscisic acid (ABA), gibberellic acid (GA), zeatin (Z), N⁶-benzyladenine (BA), α-naphthaleneacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D) in young coconut water (CW). The analysis was carried out using a reverse-phase HPLC gradient elution, with an aqueous mobile phase (containing 0.1% formic acid, pH adjusted to 3.2 with triethylamine (TEA)) modified by methanol, and solute detection made at 265 nm wavelength. The method was validated for specificity, quantification, accuracy and precision. After preconcentration of putative endogenous phytohormones in CW using C₁₈ solid-phase extraction (SPE) cartridges, the HPLC method was able to screen for putative endogenous phytohormones present in CW. Finally, the identities of the putative phytohormones present in CW were further confirmed using independent liquid chromatography–tandem mass spectrometry (LC–MS/MS) equipped with an electrospray ionization (ESI) interface.     

超高效液相色谱-三重四级杆串联质谱法同时测定植物组织中多种激素

建立了同时测定植物组织中玉米素(ZT)、吲哚乙酸(IAA)、赤霉素类(GA1、GA3、GA4)、脱落酸(ABA)、茉莉酸(JA)7种植物激素的超高效液相色谱-三重四级杆串联质谱法(UHPLC-QqQ-MS/MS)。采用C18色谱柱(50×2.1mm,1.8μm)分离,以甲醇-0.1%甲酸水溶液为流动相,梯度洗脱,在多反应监测(MRM)模式下进行定性定量分析,外标法定量。7种植物激素的检出限为0.01~8.77ng·mL~(-1),定量限为0.02~29.23ng·mL~(-1),在实验所采用的浓度范围内线性相关系数(R2)在0.9870~0.9990之间。植物样本前处理采用C18-SPE小柱进行富集和纯化,极大地减少了基质干扰。在辣椒叶片基质中,7种植物激素在低、中、高3个加标水平下的平均回收率为65.8%~90.9%,相对标准偏差(RSDs,n=5)为2.1%~5.5%。该方法简单、快速,灵敏,准确,适用于对植物组织中多种激素的同时测定。     

全自动在线固相萃取-液相色谱-串联质谱法同时检测水稻中6种内源性植物激素

建立了同时检测水稻中6种内源性植物激素脱落酸( Abscisic acid,ABA)、吲哚-3-乙酸( Indole-3-acetic acid, IAA)、水杨酸( Salicylic acid,SA)、茉莉酸( Jasmonic acid,JA)、吲哚-3-丙酸( Indole-3-propionic acid, IPA)和吲哚-3-丁酸( Indole-3-butyric acid,IBA)的全自动在线固相萃取-液相色谱-串联质谱方法。植物样品经过甲醇提取,采用C18固相萃取柱富集净化,流动相将待测物洗脱至C18分析色谱柱进行分离,最终使用串联四极杆质谱进行检测。方法的线性范围为8~320μg/L,相关系数为R2≥0.99;方法的检出限(S/N=3)范围为0.1~0.8μg/kg;实际样品中方法回收率范围为71.2%~126%,RSD<13%。应用本方法快速、准确地检测了水稻幼穗中多种内源性植物激素的含量,并与目前植物学领域内常用的检测方法进行了比较。同时,本方法对水稻受伤叶片的内源植物激素含量变化进行了定量分析,其含量随受伤时间的变化趋势与其生物背景的实验结果相吻合。     

Simultaneous Determination of Phytohormones in Plant Extracts using SPME and HPLC

Solid-phase microextraction followed by HPLC was used for the determination of indole-3-acetic acid (IAA), abscisic acid (ABA), indole-3-butyric acid (IBA) and 1-naphthylacetic acid (NAA) in plant samples. Parameters influencing performance, including pH, salinity, extraction time, fiber coating and temperature, were optimized. A Carbowax-coated fiber was chosen for determination due to much higher extraction efficiency compared to polyacrylate fibers. The dynamic ranges spanned over three orders of magnitude. The LOD/(LOQ) values of the target compounds in pure water were 0.149(0.497), 0.442(1.472), 0.121(0.403), 0.058(0.193) μg L⁻¹ for IAA, ABA, IBA and NAA respectively. The method was successfully applied to the analysis of xylem fluid from Musa basjoo stem obtaining recoveries of 98.85% (IAA), 94% (IBA) and 94.30% (NAA). The method was also successfully applied to the analysis of these four target compounds in the hyperaccumulating plant, Viola baoshanensis. The results matched quite well with ones obtained by solid phase extraction followed by HPLC. The method developed was superior when applied to liquid samples because matrix effects could be eliminated.     

双层固相萃取-液相色谱/串联质谱法测定水稻中独脚金内酯

本文结合双层固相萃取和液相色谱-串联质谱法(LC-MS/MS),建立了水稻中内源性独角金内酯(Strigolactone,SLs)的快速分析方法。水稻根提取液经过石墨化炭黑/混合模式阴离子交换吸附剂+混合模式阳离子交换吸附剂(GCB/MAX+MCX)双层固相萃取柱除杂后,通过LC-MS/MS法分析检测。实验优化了固相萃取条件,并进行了方法学验证。结果表明,SLs在对应范围内线性关系良好(相关系数大于0.9972),方法检出限(S/N=3)为0.007~0.028ng/g,回收率为82.1%~115.8%,相对标准偏差(n=6)在1.9%~14.1%之间。建立的方法灵敏度高、重现性好,可用于水稻中内源性SLs的准确定量。     

Induced Chemical Defense in Plants

Surprising parallels exist between the chemical defense mechanisms of plants and animals. The biosynthesis of defensive substances in plants can be induced by microbial or herbivoral attack. Recent results demonstrate that the chemical defense of plants is mediated by lipid-based signaling systems. Volicitin ( 1 ) acts as a chemical signal in a tritrophic interaction of plants and insects. Derivatives of jasmonic acid ( 2 ) play a key role in directing the chemical defense response.