Shikimic acid accelerates phase change and flowering in Chinese jujube

The juvenile-to-adult phase change with first flowering as the indicator plays a crucial role in the lifecycle of fruit trees. However, the molecular mechanisms underlying phase change in fruit trees remain largely unknown. Shikimic acid (ShA) pathway is a main metabolic pathway closely related to the synthesis of hormones and many important secondary metabolites participating in plant phase change. So,whether ShA regulates phase change in plants is worth clarifying. Here, the distinct morphological characteristics and the underlying mechanisms of phase change in jujube (Ziziphus jujuba Mill.), an important fruit tree native to China with nutritious fruit and outstanding tolerance abiotic stresses, were clarified. A combined transcriptome and metabolome analysis found that ShA is positively involved in jujube(Yuhong’×Xing 16’) phase change. The genes in the upstream of ShA synthesis pathway (ZjDAHPS, ZjDHQS and ZjSDH), the contents of ShA and the downstream secondary metabolites like phenols were significantly upregulated in the phase change period. Further, the treatment of spraying exogenous ShA verified that ShA at a very low concentration (60 mg·L^(-1)) can substantially speed up the phase change and flowering of jujube and other tested plants including Arabidopsis, tomato and wheat. The exogenous ShA (60 mg·L^(-1)) treatment in jujube seedlings could increase the accumulation of endogenous ShA, enhance leaf photosynthesis and the synthesis of phenols especially flavonoids and phenolic acids, and promote the expression of genes (ZjCOs, ZjNFYs and ZjPHYs) involved in flowering pathway. Basing on above results, we put forward a propose for the underlying mechanism of ShA regulating phase change, and a hypothesis that ShA could be considered a phytohormone-like substance because it is endogenous, ubiquitous, movable and highly efficient at very low concentrations. This study highlights the critical role of ShA in plant phase change and its phytohormone-like properties.

Extraction and Content Determination of Shikimic Acid in Pinus elliottii Engelm

[Objective] The aim was to provide scientific basis for development and utilization of Pinus elliottii Engelm resources.[Method] The extraction process of shikimic acid in Pinus elliottii Engelm was studied,and the content of shikimic acid was determined by HPLC.The HPLC conditions were as follows;Alltima NH2 （5 μm,4.6 mm × 150 mm） column separation;the mobile phase was acetonitrile-2%H3PO4 （90：10）;the flowing velocity was 1 ml/min;test wavelength was 213 nm,the width of belt was 16 nm;reference wavelength was 300 nm,the width of belt was 80 nm.[Result] By the single factor and orthogonal tests,the optimum conditions were found as follows：ethanol concentration 60%,extraction temperature 75 ℃,solid-liquid ratio 1：25,extraction time 2.5 h.The extraction rate of shikimic acid was 1.49%.[Conclusion] Shikimic acid in Pinus elliottii Engelm could be used as a new resource to develop and utilize.

Effects of Acetylsalicylic Acid (ASA) and Ethylene Treatments onRipening and Softening of Postharvest Kiwifruit

Kiwifruit (Actinidia deliciosa (A. Chev.) C. F. Liang et A. R. Ferguson cv. Bruno) was used toinvestigate the effects of acetylsalicylic acid (ASA, 1.0 mmol/L, pH 3.5) and ethylene (100 mL/L) treat-ments on changes at endogenous salicylic acid (SA) levels and other senescence-related factors duringfruit ripening and softening at 20 ℃. The level of endogenous SA in ripening fruits declined and a closerelationship was observed between the change at endogenous SA level and the rate of fruit ripening andsoftening. ASA treatment elevated SA level in the fruit, slowed down the increases in lipoxygenase (LOX)and allene oxide synthase (AOS) activities, decreased the O22-. production in the preclimacteric phase andthe early phase of ethylene climacteric rise, maintained the stability of cell membrane, inhibited ethylenebiosynthesis, postponed the onset of the ethylene climacteric, and delayed the process of fruit ripeningand softening. On the contrary, application of ethylene to ripening kiwifruit resulted at a lower SA level, anaccelerated increases in the activities of LOX and AOS and the rate of O22-. production, an elevated relativeelectric conductivity and an advanced onset of ethylene climacteric, and a quicker fruit ripening andsoftening. It is suggested that the effects of ASA on ripening kiwifruit can be attributed to its ability toscavenge O22-. and/or to maintain stability of cell membrane.

Application of advanced oxidation processes for removing salicylic acid from synthetic wastewaters

In this study,advanced oxidation processes(AOPs) such as anodic oxidation(AO),UV/H_2O_2 and Fenton processes(FP) were investigated for the degradation of salicylic acid(SA) in lab-scale experiments.Boron-doped diamond(BDD) film electrodes using Ta as substrates were employed for AO of SA.In the case of FP and UV/H_2O_2,most favorable experimental conditions were determined for each process and these were used for comparing with AO process.The study showed that the FP was the most effective process under aci...

Facile Syntheses of (6S)-6-Fluoroshikimic Acid and (6R)-6-Hydroxyshikimic Acid

(6S)-6-Fluoroshikimic acid 2 and (6 R ) 6 hydroxyshikimic acid 3 have been synthesized via an OsO 4 catalysed dihydroxylation of diene 7, which was derived from (-) shikimic acid 1.

不同浓度外源SA对“赤霞珠”果实品质的影响

以8年生酿酒葡萄品种“赤霞珠”为试验材料,在葡萄转色期7月下旬到8月上旬喷施SA,探究在果实发育中SA对果实品质的影响,为改善酿酒葡萄品质提供参考。结果表明,对葡萄叶面喷施SA,整个生长周期“赤霞珠”百粒重无显著差异,葡萄进入转色期后,各SA处理下葡萄果实中糖类物质均逐渐增加,有机酸含量逐渐减少,采收期时,糖类物质含量达到最高,有机酸含量达到最低。采收期(花后110 d),5 mmol/L SA处理可以明显降低葡萄中可滴定酸含量,3 mmol/L SA处理可以显著提高葡萄果实中糖类物质和酚类物质含量。3 mmol/L SA处理有利于“赤霞珠”葡萄果实品质的改善。

Science Letters:Anodic oxidation of salicylic acid at Ta/BDD electrode

Boron-doped diamond （BDD） film electrodes using Ta as substrates were employed for anodic oxidation of salicylic acid （SA）. The effects of operational variables including initial concentration, current density, temperature and pH were examined. The results showed that BDD films deposited on the Ta substrates had high electrocatalytic activity for SA degradation. There was little effect ofpH on SA degradation. The current efficiency （CE） ,aas fbund to be dependent mainly on the initial SA concentration, current density and temperature. Chemical oxygen demand （COD） was reduced from 830 mg/L to 42 mg/L under a current density of200A/m^2 at 30℃.

Effects of Salicylic Acid on the Growth and Some Physiological Characters in Salt Stressed Tomato Plants （ Solanum L ycopersicum）

Excessive soil salinity is an important constraint limiting the distribution of plants in natural habitats, and is an increasingly severe agricultural problem in arid and semi-arid regions. Higher salinity levels caused significant reduction in growth parameters like leaf area, leaf length and root and shoot dry weight. Salicylic acid （SA）, a plant phenolic is now considered as a hormone-like endogenous regulator, and its role in the defence mechanisms against biotic stressors has been well documented. In recent years its role has been widely investigated in abiotic stress （salinity, drought, water deficit and so on）. The aim of the present work was to study the effects of salicylic acid on growth and some physiological characters of salt stressed tomato plants. The presence of salicylic acid at low concentration （0.01 mM） in culture medium riched with NaCl 100 mM （6 g·L^-1） improves the tolerance of tomato cv. Golden Sunrise to salinity. This amelioration results in stimulation of growth and development of plants. The applied of SA in saline medium induce： （i） an increase in chlorophyll content; （ii） a better supply of essential elements in plant growth, such as K＋; （iii） a decrease in toxic ions such Na＋ and CI in aerial organs; and （iv） an additional synthesis of organic solutes and osmoprotectors like proline and proteins. All these results suggest that salicylic acid could be successfully used in alleviating depressive effects of salt on the productivity of the cultivated tomato.

盐胁迫下SA在大花烟草中以剂量依赖方式调节种子萌发和生长

以改造的大花烟草(Nicotiana alata)即早花烟草为试材,研究在1500 mmol·L^(-1)氯化钠(NaCl)胁迫下,不同浓度梯度外源水杨酸(SA)处理下早花烟草种子的萌发情况和植株的生长状况,分析其过氧化物酶(POD)酶活性、超氧化物歧化酶(SOD)酶活性和活性氧(ROS)含量,及其作用机制.研究结果表明,适量外源SA可以缓解盐胁迫对早花烟草萌发的毒害.经0.05~1.00 mmol·L^(-1) SA处理,盐胁迫下早花烟草种子的发芽势、发芽率、发芽指数及活力指数上升,但随着SA浓度继续升高,其缓解效应随之降低.盐胁迫下的早花烟草生长已经受到严重抑制.喷施0.5~1.5 mmol·L^(-1) SA后,叶片大小和鲜重、根系的大小和鲜重都明显升高;且喷施0.5~2.0 mmol·L^(-1) SA叶片中SOD和POD活性均呈现先降低后上升的趋势;ROS含量呈现先降低后上升的趋势;叶绿素含量呈现出先上升后降低的趋势.这些结果表明:SA调节耐盐性可能以剂量依赖的方式发生,在外源施加适量浓度的SA提高抗氧化酶活性,能有效地消除过量的ROS,避免ROS积累,降低叶片中叶绿素含量及对光系统和光合碳同化过程中多种酶的伤害,维持较高的光合速率.

长江中下游棉田马唐(Digitaria sanguinalis)对草甘膦的抗药性初步研究

采用培养皿种子检测法和整株植物测定法的测定了从长江中下游3个省13个县棉田采集的18个马唐(Digitaria sanguinalis)种群,其草甘膦抗药性水平,并采用分光光度计测定了1个相对敏感种群和3个相对抗性种群在施用草甘膦后莽草酸积累量和谷胱甘肽S￣转移酶(glutathione S-transferase,GST)活力的变化情况。整株植物测定法结果表明:湖南常德安障乡地区马唐种群相对抗性水平最高,抗性指数为7.637,培养皿种子检测法与整株植物测定法测定的结果基本一致。测定的4个种群莽草酸积累量均随时间的变化而上升,其中3个抗性马唐种群的莽草酸积累量在9 d内始终低于相对敏感种群。4个种群GST活力变化无显著性差异,表明GST的代谢活力与马唐对草甘膦产生抗药性不相关。

水杨酸(SA)对果实成熟的影响

水杨酸是一种天然抑制剂，对植物有多种多样的作用，新近研究报道，它是乙烯生物合成的一种新的抑制剂。本文用水杨酸处理番茄、苹果、梨等果实，储藏在室温下，不时检查ＳＡ对果实贮存保鲜的影响。其结果表明ＳＡ处理的果实，ＰＧ活性比对照低，而硬度大，抗病力强。番茄，苹果和梨的无病好果率比对照果提高１０％以上。上述结果证明，用ＳＡ处理绿熟番茄及梨和苹果，能有效保存果实新鲜，增强抗病力和延长货架的寿命。

Screening for Glyphosate Resistant Wild Soybean(Glycine soja) and Study on Its Physiological Mechanisms of Resistance

[Objective] This study aimed to preliminarily determine the physiological mechanism of glyphosate resistance produced in wild soybean（Glycine soja） and further provide a basis for the breeding of glyphosate-resistant soybean. [Method] First,a screening for glyphosate resistant varieties among sixty-seven wild soybean materials was done in a field trial; subsequently, physiological indexes of the screened resistant variety ZYD0685 and the sensitive variety ZYD0790 were studied. [Result]At the glyphosate dose of 1.23 kg a.i/hm2, glyphoaste resistance varied greatly among different wild soybean materials, with the highest survival rate of 87% and83% occurring in ZYD0685 and ZYD2405, respectively, and that of another seven accessions ranged from 2.7% to 38%, and all the remaining fifty-eight soybean materials died. After treatment with glyphoaste at different doses, there were no significant differences in chlorophyll content and shikimate content in the resistant ZYD0685, but there was an evident increase in the activity of gultathione-S-transferases（GSTs）; while in the sensitive ZYD0790, the content of shikimic acid increased significantly, and chlorophyll content decreased significantly, and GSTs activity revealed a slight change. [Conclusion] Therefore, lowering the amount of accumulated shikimic acid is the major physiological response to glyphosate in wild soybean.

3,4-O-异亚丙基莽草酸(ISA)在Beagle犬体内的药代动力学研究

目的:建立 Beagle 犬血浆中3,4-O-异亚丙基莽草酸(ISA)的 RP-HPLC 分析方法,并对 ISA 原料药静注给药在犬体内药动学过程进行分析研究。方法:犬血浆样品中加入内标物芦丁,采用酸性甲醇沉淀蛋白质并提取药物,采用 RP-HPLC法测定。大连依利特 Hypersil ODS 2柱(250 mm×4.6 mm,5μm);流动相:甲醇-0.3%醋酸(50:65);检测波长:220 nm;柱温:室温;流速:1.0 mL·min^(-1)。动物实验使用 Beagle 犬6只,采用静脉注射给药(200 mg·kg^(-1)),进行血药浓度测定。结果:犬血浆样品中 ISA 无干扰,以芦丁为内标,测定血药浓度最低检测限3 ng·mL^(-1);ISA 浓度在0.01～600μg·mL^(-1)范围内对ISA 峰面积和内标峰面积的比有较好的线性关系,r=0.9996,绝对回收率大于70%,方法回收率在98.5%～103.3%之间;日内精密度、日间精密度 RSD 分别小于5%和15%。ISA 原料药静脉注射在犬体内过程符合二室模型。结论:本法准确、灵敏度较高,可用于 ISA 体内过程的研究。

不同浓度水杨酸(SA)浸种对盐旱交叉胁迫下黑果枸杞种子萌发的影响

以黑果枸杞种子为试材,5种不同浓度SA浸种12 h,将不同浓度NaCl溶液及PEG-6000溶液按不同比例混合模拟20种盐旱交叉胁迫,培养皿滤纸萌发并观测SA处理对盐旱交叉胁迫下黑果枸杞种子萌发指标,分析SA处理对其抗盐旱特性的影响。结果表明:在盐旱交叉胁迫下,随着胁迫强度的增加,黑果枸杞种子的发芽率、发芽势均呈先升后降的趋势,低浓度SA处理组较对照可以提高黑果枸杞种子的发芽率和发芽势,其中S1处理组效果最好;黑果枸杞种子的发芽指数与干旱胁迫程度呈负相关,单一盐胁迫及交叉胁迫下,发芽指数和活力指数先升后降,轻度胁迫和低浓度SA可以在一定程度上提高种子活力;随着干旱胁迫程度的加剧,黑果枸杞幼苗相对根长先增后减;随着盐胁迫的程度加剧,黑果枸杞幼苗相对根长大幅减少。对不同浓度SA浸种后黑果枸杞耐盐旱性进行综合评价,可以看出,低浓度SA浸种可以提高黑果枸杞种子萌发期的耐盐旱性。说明黑果枸杞种子在萌发期对盐旱胁迫有一定的交叉适应性,且盐旱胁迫下,0.05 mM SA处理增强黑果枸杞种子萌发阶段耐盐旱性效果最佳。

外源SA对白粉桃低温胁迫下花器的生理效应

用0、0.5、1.0、2.05、.0 mmol/L 5种浓度的水杨酸(SA)溶液喷施白粉桃花蕾,然后在3℃下进行低温胁迫处理,研究了SA对桃花抗冷性的影响.结果表明,SA可以增强桃花的抗冷性,其中以1.0 mmol/L处理的效果最好,处理48 h后,MDA、O2-、H2O2含量分别降低了53%4、1.5%、24.59%,且与对照间差异达到极显著水平;而与植物抗性相关的Pro含量在处理48 h后,比对照升高了31.74%,与对照间的差异也达到极显著水平.从试验中还可以看出SOD、POD这2种保护酶的活性受到O2-、H2O2含量的调节,推测这2种酶可能是作为细胞的保护应激物质来增强桃花的抗寒性.

外源水杨酸(SA)对高温胁迫下葡萄幼苗耐热性诱导研究

为探讨外源水杨酸(SA)对高温胁迫下葡萄幼苗耐热性的影响,以二年生克瑞森无核葡萄扦插苗为试验材料,对清洗干净的葡萄叶片喷施浓度为150μmol/L的水杨酸(SA)溶液,之后置于45℃高温胁迫10,30,60,120,240,480min,以喷施蒸馏水后置于45℃高温胁迫10,30,60,120,240,480min为对照,研究外源水杨酸对可溶性蛋白含量、蛋白激酶活性、游离脯氨酸含量、电解质渗透率、丙二醛含量生理指标的影响。结果表明,高温胁迫下外源水杨酸(SA)增加可溶性蛋白和游离脯氨酸的含量;外源水杨酸诱导葡萄叶片蛋白激酶活性,促进蛋白磷酸化反应。可溶性蛋白含量变化与蛋白激酶活性的变化具有高度的一致性,即胁迫60min时可溶性蛋白含量增加到最大,蛋白激酶活性也同时增高到最大值;随着胁迫时间的延长(>60min),外源水杨酸显著降低丙二醛的含量和相对电导率。外源水杨酸随着高温胁迫时间的延长(>60min)可以显著增加葡萄幼苗叶片内可溶性蛋白和游离脯氨酸含量,降低丙二醛含量和电解质渗透率,显著降低细胞膜质过氧化伤害;增强蛋白激酶活性,促进蛋白磷酸化的反应,提高葡萄的耐热性。

外源SA、GSH对Cd胁迫下绵毛水苏生理和生长的影响

为探究不同外源物质对Cd胁迫下绵毛水苏生理和生长的缓解效果,采用盆栽试验研究叶面喷施不同浓度水杨酸(SA)(0.5、1.0、1.5、2.0 mmol·L^(-1))和谷胱甘肽(GSH)(0.1、0.2、0.3、0.4 mmol·L^(-1))对300 mg·kg^(-1)Cd胁迫下绵毛水苏幼苗生长、渗透调节物质、抗氧化酶活性以及Cd含量等的影响。结果表明,外源SA和GSH改善了植物的叶色,提高了叶面积和萌蘖能力,并增加了地下、地上部干物质积累量。除0.4 mmol·L^(-1)GSH处理第3天外,外源SA和GSH处理均提高了可溶性糖、可溶性蛋白和游离脯氨酸等渗透调节物质的含量,最高增幅分别为16.06%、14.13%、311.39%(SA)和50.28%、12.77%、313.77%(GSH);此外,SA和GSH分别使抗氧化酶(SOD、POD和CAT)活性最高增幅依次达57.39%、38.51%、26.81%和85.00%、60.77%、50.21%。绵毛水苏吸收的Cd主要累积在根部,外源SA对Cd吸收无明显影响,而GSH抑制了Cd向地上部的转运。综上可知,SA和GSH对Cd胁迫下的绵毛水苏均具有缓解作用,以1.5 mmol·L^(-1)SA和0.3~0.4 mmol·L^(-1)GSH效果较佳。本研究结果对绵毛水苏应用于Cd污染土壤植物修复具有重要意义。

SA对高温胁迫下葡萄幼苗AsA-GSH循环的影响

本试验以二年生克瑞森无核葡萄为材料,探讨了外源SA对高温胁迫下葡萄体内ASA-GSH循环代谢的影响及其在抗高温胁迫中的作用。试验结果表明,与对照相比,外源SA可以促进高温胁迫下葡萄叶片内ASA和GSH含量的积累量,降低GSSG的含量。长时间(>240min)的高温胁迫下,外源SA可以降低脱氢抗坏血酸(DHA)的含量;能够维持较高的As A-GSH循环系统中APX、DHAR、MDHAR、GR活性。外源SA促进了高温胁迫下葡萄ASA-GSH循环的快速而有效的运转,降低了高温胁迫对葡萄植株的氧化伤害,从而缓解了高温胁迫对葡萄幼苗的伤害作用。

SA浸种对盐胁迫下小麦种子萌发和幼苗生长的影响

以小麦盐敏感品种鲁麦15为材料,研究了外源水杨酸(salicylic acid,SA)浸种对100 mmol/L NaCl胁迫下小麦种子萌发和幼苗生长的影响。研究结果表明:盐胁迫下,无论经SA浸种还是未经SA浸种,小麦幼苗的生长均受到明显抑制,干、鲜重显著下降;0.1 mmol/L、0.2 mmol/L和0.3 mmol/L SA溶液浸种均能显著缓解NaCl胁迫对小麦幼苗生长的抑制,其中以0.2 mmol/L SA溶液浸种预处理效果最好。实验中,0.2 mmol/L SA浸种可显著提高盐胁迫下小麦种子β-淀粉酶的活性和吸胀速率。此外,与未经SA浸种的盐胁迫小麦幼苗相比,0.2 mmol/L SA浸种的盐胁迫小麦幼苗整株的干、鲜重显著增加,幼苗体内Na^+含量降低,K^+含量和K^+/Na^+比值显著提高;同时,小麦幼苗叶片中超氧化物歧化酶(superoxide dismutase,SOD)、过氧化氢酶(catalase,CAT)、过氧化物酶(peroxidase,POD)活性升高,而丙二醛(MDA)含量则显著降低。由此可以得出,SA浸种能有效提高盐胁迫下小麦幼苗体内K^+/Na^+比值,提高SOD、CAT和POD的活性,减轻膜脂过氧化程度,以缓解盐胁迫对小麦幼苗生长的抑制作用,从而提高耐盐性。

外源SA浸种对盐胁迫下小油菜幼苗地上部生长及生理特性的影响

以小油菜"五月慢"幼苗为试材,研究了不同浓度外源SA浸种对盐胁迫下小油菜幼苗株高、叶面积、地上部干质量、过氧化物酶(POD)活性和超氧化物歧化酶(SOD)活性等指标的影响,探究外源水杨酸(SA)浸种对盐胁迫下小油菜幼苗地上部分生长及生理特性的影响。结果表明:在相同盐胁迫条件下,不同浓度外源SA浸种各指标均表现出低浓度促进、高浓度抑制现象,其中以1.00 mmol·L-1的SA浸种缓解盐胁迫效果最佳。在同一浸种浓度下,随着盐浓度的增加,株高、叶面积、地上部干质量均呈减少趋势。POD、SOD活性则在50 mmol·L-1盐胁迫下显著升高,随后降低。说明一定浓度SA浸种可以缓解盐胁迫对小油菜幼苗地上部分生长及生理特性的影响。