咖啡酸和氯化钴对茉莉酸甲酯诱导抗病相关酶活性的影响

烟草愈伤组织在含咖啡酸(5mmol/L)和／或CoCl2(10mmol/L,乙烯合成抑制剂)的MS培养基上暗培养,同时用莱莉酸甲酯(1mg／d,简称MJ)处理愈伤组织。处理后测定乙烯、水杨酸和病程相关蛋白(PR)含量及一些抗病相关酶活性。MJ明显促进乙烯产生、增加水杨酸和PR蛋白含量,提高苯丙氨酸解氨酶(PAL)、β1,3—葡聚糖苷酶和几丁酶的活性。咖啡酸降低MJ对乙烯和水杨酸诱导,CoCl2明显降低MJ对乙烯的诱导,但没有明显影响MJ对水杨酸的诱导,两者都促进MJ诱导PAL活性而抑制MJ诱导β1,3—葡聚糖苷酶活性。咖啡酸明显影响MJ诱导内切几丁酶,几乎完全抑制对外切几丁酶的诱导;CoCl2对MJ诱导内切几丁酶没有影响,促进对外切几丁酶的诱导。实验结果表明,不同的抗病相关酶活性诱导有不同的信号传递途径,在所测几种酶的诱导中,水杨酸起主要作用,乙烯作用较小,MJ的诱导作用主要是由水杨酸所转导。     

咖啡酸和氯化钴对茉莉酸甲酯诱导抗病相关酶活性的影响

烟草愈伤组织在含咖啡酸（5 mmol/L）和/或CoCl2(10 mmol/L,乙烯合成抑制剂)的MS培养基上暗培养,同时用茉莉酸甲酯（1 mg/ml,简称MJ）处理愈伤组织。处理后测定乙烯、水杨酸和病程相关蛋白（PR）含量及一些抗病相关酶活性。MJ明显促进乙烯产生、增加水杨酸和PR蛋白含量,提高苯丙氨酸解氨酶（PAL）、β1,3-葡聚糖苷酶和几丁酶的活性。咖啡酸降低MJ对乙烯和水杨酸诱导,CoCl2明显降低MJ对乙烯的诱导,但没有明显影响MJ对水杨酸的诱导,两者都促进MJ诱导PAL活性而抑制MJ诱导β1,3-葡聚糖苷酶活性。咖啡酸明显影响MJ诱导内切几丁酶,几乎完全抑制对外切几丁酶的诱导;CoCl2对MJ诱导内切几丁酶没有影响,促进对外切几丁酶的诱导。实验结果表明,不同的抗病相关酶活性诱导有不同的信号传递途径,在所测几种酶的诱导中,水杨酸起主要作用,乙烯作用较小,MJ的诱导作用主要是由水杨酸所转导。     

新疆甜瓜经疫霉菌毒素诱导后酶活性的变化（简报）

抗病性不同的新疆甜瓜品种经疫霉菌毒素诱导后,PAL活性在总体上呈上升趋势,且与品种的抗感病程度的顺序一致;POD活性初期下降,8h后开始上升,24h达最大值,随后下降;几丁内切酶与几丁外切酶的第一活性峰均出现在诱导后16h,而第二活性峰出现的时间团品种抗病性差异而不同;β-1,3-葡聚糖酶的活性变化与几丁质酶基本一致。     

毛头鬼伞多糖对烟草酶活性和同工酶谱的影响

分析了毛头鬼伞(Coprinus comatus)真菌多糖诱导烟草对烟草花叶病毒(TMV)抗性过氧化物酶(POD)、多酚氧化酶(PPO)、苯丙氨酸解氨酶(PAL)、几丁质酶、-β1,3-葡聚糖酶活性的变化。结果表明,毛头鬼伞多糖可提高POD、PPO、PAL、几丁质酶和-β1,3-葡聚糖酶的活性,接种TMV后毛头鬼伞多糖处理的烟草酶活性显著高于不处理者。上述结果提示,毛头鬼伞多糖处理后烟草酶活性的增强可能与其诱导烟草获得抗性有关。     

诱抗处理对甜瓜叶片防卫酶活性的影响

以黄河蜜幼苗为材料,分析了化学诱导物处理后甜瓜叶片中几丁质酶(CHI)、β-1,3葡聚糖酶(GLU)、苯丙氨酸解氨酶(PAL)和多酚氧化酶(PPO)活性的变化.结果显示:经5种化学诱导物处理后,甜瓜叶片PAL活性快速增加,于处理后第6天出现活性高峰;苯丙噻二唑(BTH)、水杨酸(SA)、草酸(OAA)和硅酸钠(Na2SiO3)处理后GLU活性变化与PAL相似,PPO活性在测定期内持续升高;磷酸氢二钾(K2HPO4)处理对GLU和PPO活性无明显影响;SA处理后叶片CHI活性明显升高,其它诱导物处理对CHI活性无明显影响.结果表明,防卫酶(特别是GLU和PPO)活性表达增强是BTH、OAA、SA和Na2SiO3等诱导物处理系统诱导甜瓜幼苗白粉病抗性增强的重要生化机制.     

新疆甜瓜疫霉菌毒素对新疆甜瓜黄化苗中β-1,3-葡聚糖酶和几丁酶活性的诱导(简报)

经瓜类疾霉菌培养物中提取的毒素处理的新疆甜瓜黄化苗中，β－1，3－葡聚糖酶和内切、外切几丁酶的活性都有明显升高；亚胺环已酮和5－氟尿嘧啶均抑制这些酶的活性。     

两种水杨酸代谢相关酶在逆境龙须菜中的活性研究

旨在探索水杨酸(Salicylic acid,SA)信号通路相关的两种酶——苯丙氨酸解氨酶(PAL)和β-1,3-葡聚糖酶(β-1,3-GA)在病烂、盐度、温度逆境和添加SA条件下在龙须菜中的活性变化。结果表明,3组病烂龙须菜中PAL和β-1,3-GA活性分别增加为对照组的1.27-1.42倍和1.26-1.35倍;高盐条件下PAL活性与对照组无显著差别,而β-1,3-GA活性在24 h和48 h分别增加为对照组的1.90倍和1.42倍;高温组PAL和β-1,3-GA活性在24 h均显著升高,分别是对照组的1.25倍和1.27倍;100μmol/L SA添加后PAL和β-1,3-GA的活性升高,但高浓度SA却抑制了两种酶的活性。结果表明,在逆境胁迫下龙须菜中PAL和β-1,3-GA的活性增加与水杨酸的抗逆作用有关,而100μmol/L SA诱导两种酶的效果最显著。     

香蕉采后炭疽病发生与几丁酶、β-1,3-葡聚糖酶和多巴胺的关系

几丁酶、β－1,3-葡聚糖酶随着香蕉术后炭疽病的发展过程,活性逐渐增加;但当果实出现明显病害症状时活性略有下降。施保功处理在抑制香蕉采后炭疽病发生的同时也抑制了芭蕉炭疽菌可能诱导的几丁酶和β-1,3-葡聚糖酶活性的增加。多巴胺在香蕉采收时含量较高,但随着炭疽病的发生明显下降。对“黑油身”和“63－1”两个不同抗病品种分析表明,前者几丁酶和β－1,3-葡聚糖酶活性和多巴胺含量较高与其较强的抗病性相一致。     

茉莉酸甲酯对烟草愈伤组织一些活性氧生成和相关酶活性的影响

烟草愈伤组织用茉莉酸甲酯(MJ, 1mgml-1)处理;同时将愈伤组织在含AIP(0.1mmol/L,水杨酸合成抑制剂)和/或AOA(1mmol/L,乙烯合成抑制剂)的MS培养基上进行暗培养,测定在活性氧产生和脂质过氧化中起作用的相关酶活性及一些代谢物的含量。结果表明,茉莉酸甲酯能激活超氧阴离子的产生,提高脂氧合酶同工酶1(LOX1)的活性从而启动脂质过氧化,对脂氧合酶同工酶3(LOX3)没有明显影响;降低过氧化氢(H2O2)的含量、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)及抗坏血酸过氧化物酶(APX)等保护酶的活性,减少了膜脂过氧化中有毒物质丙二醛(MDA)的含量。AIP和AOA都对MJ的作用有不同程度的影响。MJ调节超氧阴离子和过氧化氢生成以及相关酶活性是通过不同的信号转导途径,MJ调节超氧阴离子和MDA生成、SOD和APX活性很可能是通过乙烯起作用,且对MDA生成和APX活性的调节可能通过水杨酸起作用;MJ直接调节LOX1活性,但对LOX3活性没有明显作用。     

新疆甜瓜疫霉菌毒素对新疆甜瓜黄化苗中β—1,3—葡聚糖酶和几丁酶？…

经瓜类疫霉菌培养物中提取的毒素处理的新疆甜瓜黄化苗中,β－１,３－葡聚糖酶和内切、外切几丁酶的活性都有明显升高;亚胺环已酮和－５氟尿嘧啶均抑制这些酶的活性。     

Optical Resolution by Preferential Crystallization of (RS)-2-Amino-3-(2-carboxyethylthio)propanoic Acid

Electrophilic additions of DL- and L-Cys to propenoic acid afforded (RS)- and (R)-2-amino-3-(2-carboxyethylthio)propanoic acids [(RS)- and (R)-ACE], respectively. (RS)-ACE was found to exist as a conglomerate based on its melting point, solubility, and infrared spectrum. (RS)-ACE was optically resolved by preferential crystallization to yield (R)- and (S)-ACE. The obtained (R)- and (S)-ACE were efficiently recrystallized from water, taking account of the solubility of (RS)-ACE, to give them in optically pure form.     

Preparation of Single-Enantiomer Biofunctional Molecules with (S)-2-Methoxy-2-(1-naphthyl)propanoic Acid

(RS)-β-Ionol and (RS)-2-methyl-4-octanol were resolved by using (S)-2-methoxy-2-(1-naphthyl)propanoic acid [(S)-MαNP acid]. The specific stereochemistry of each MαNP ester was elucidated by 2D NMR analyses, and shielding by the 1-naphthyl group was observed in both the ¹H- and ¹³C-NMR spectra. Solvolysis of the individual (S)-MαNP esters gave four single-enantiomer alcohols. The normal-phase HPLC elution order of each MαNP ester is also discussed.     

2-吗啉乙磺酸(MES)对拟南芥幼苗生长的影响

本实验研究0.05% MES对野生型拟南芥生长的影响。结果表明,含有MES的培养基pH变化较小,其培养10 d的拟南芥幼苗干重、鲜重、叶绿素含量和含水量均高于对照组,而叶片PAL和POD活性却低于对照组,说明MES通过影响培养基的pH变化促进拟南芥生长。     

Synthesis of Optically Active 1,4-Thiazane-3-carboxylic Acid via Optical Resolution by Preferential Crystallization of (RS)-2-Amino-3-[(2-chloroethyl)sulfanyl]propanoic Acid Hydrochloride

Optically active 1,4-thiazane-3-carboxylic acid [TCA] was synthesized from cysteine via optical resolution by preferential crystallization. The intermediate (RS)-2-amino-3-[(2-chloroethyl)sulfanyl]propanoic acid hydrochlo-ride [(RS)-ACS?HCl] was found to exist as a conglomerate based on its melting point, solubility and IR spectrum. (RS)-ACS?HCl was optically resolved by preferential crystallization to yield (R)- and (S)-ACS?HCl. (R)- and (S)-ACS?HCl thus obtained were recrystallized from a mixture of hydrochloric acid and 2-propanol, taking account of the solubility of (RS)-ACS?HCl, efficiently yielding both enantiomers in optically pure forms. (R)- and (S)-TCA were then respectively synthesized by the cyclization of (R)- and (S)-ACS?HCl in ethanol in the presence of triethylamine.     

Preparation of 2S-(—)-4-Amino-2-Hydroxybutanoic Acid via Yeast-Catalyzed Stereoselective Reduction

The unusual amino acid S2-(—)-4-amino-2-hydroxybutanoic acid (S-AHBA) (1), a structural component of the antibiotic Amikacin, has been prepared via yeast-catalyzed stereoselective reduction of methyl-4-benzyloxycarbonyloxyamino-2-oxobutanoate (5). The most suitable yeast was found to be Saccharomyces carlsbergensis ATCC2345 and Saccharomyces sp. Edme, which gave 40% and 54% yield, respectively, of (S)-(+)-6 (88% ee).     

Synthesis of Polyoxamic Acid (2-Amino-2-deoxy-l-xylonic Acid

The rate of precipitation of the retrograded amylose product from a dil. amylose solution was determined by the centrifugal method. The results showed that the relation of the quantity of precipitate vs. time did not fit the typical second order reaction for the coalescence of colloidal particles but fitted the crystallization formula, in appearance.

The rate of precipitation was in proportion to (c-c_a)^1.5, where c is the amylose concentration and c_a the concentration of the dil. solution phase in the phase-separated solution. When the temperature dependence of the rate was treated according to the crystallization of polymers, it was found that the rate was in proportion to T_m²/T(ΔT)², where T_m is the melting point of the polymer in solution and ΔT is (T_m?T). The T_m thus obtained was 120°C for an amylose solution. These results suggested a certain correlation between the amylose retrogradation and the crystallization.     

ETHEPHON (2-CHLOROETHYLPHOSPHONIC ACID) EFFECTS ON SCENEDESMUS QUADRICAUDA (CHLOROPHYCEAE)1,2

Growth of Scenedesmus quadricauda (Turp.) Bréb. was significantly increased when the cultures were grown in Ethephon 68–241 (2-chloroethylphosphonic acid) at concentrations of 0.001–1.0 μg · ml^?1. At 0.1 μg · ml^?1, Ethephon caused a significant increase in RNA levels on a dry weight basis. Total protein and DNA levels increased but not significantly. These data indicate that ethylene, the decomposition product of Ethephon at physiological pH, has some effect on the metabolism of algae.     

Biosynthesis of Castor Oil: Effect of Polyamines on the Acylation of Lysophosphatidic Acid at the sn-2 Position with Ricinoleic Acid

Polyamines with diamine structures of chain length longer than 3C were essential for the synthesis of phosphatidic acid (PA) from ricinoleoyl-CoA and lysophosphatidic acid (LPA) by the castor LPA acyltransferase reaction, suggesting that polyamines modulate enzyme affinity for the acyl-CoA substrate in vivo.     

核酸检测技术进展及其在SARS-CoV-2核酸检测中的应用

2020年初至今，新型冠状病毒肺炎（COVID-19）疫情仍在全球多个国家流行，给全球公共卫生安全造成了严重威胁.中国在应对COVID-19的实践中，最先完成病毒核酸测序并共享序列信息，最早有效控制疫情蔓延、恢复生产，并在病毒作用人体机制研究、疫苗研发、中和性抗体发现等环节均处于世界前沿. 其中，针对病毒核酸的检测工作——试剂盒研发、检测配套设备研制、10合1混检策略及相关政策制订，有效提高了疫情防控效率、保障了百姓健康. 本文就严重急性呼吸系统综合症冠状病毒2（SARS-CoV-2）核酸检测多种方法的原理、优劣势及其配套设备等进行综述.