人参与病原茵互作代谢产物醇溶性主成分分析

采用营养液培养的方法研究了病原菌侵染对生长初期人参根系分泌物收集物组成的影响,分别从对照及菌核菌、疫霉菌、立枯丝核菌、锈腐菌诱导处理的根系分泌物收集物中检测到27、23、17、16和20种主成分,并用标准化合物对其中的11、6、6、3和9种化合物进行了验证.结果表明:病原菌诱导后人参根系分泌物收集物主成分数量明显减少;收集物中化合物类型也发生了明显变化,新增化合物多为有机酸酯、苯及酚酸类衍生物,而减少的化合物无明显规律.     

营养元素亏缺对人参根分泌物主成分的影响

采用营养液培养的方法,研究了氮、磷、钾元素亏缺对生长发育初期人参根系分泌物组成的影响.结果表明：氮、钾元素亏缺处理的人参根系分泌物组分与对照相当,分别检测到28、29和27个强色谱峰,磷元素缺失处理人参根系分泌物组分相对较少,检测到22种强色谱峰.用化学标准品分别对上述4种处理的根系分泌物中的14、14、11和10个化合物进行了鉴定.与对照相比,氮、磷元素亏缺处理人参根系分泌物有机酸和酚酸类化合物种类增多,磷元素缺失处理人参根系分泌物种类减少.说明人参生长发育初期对氮、钾元素需求比较旺盛,而对磷元素需求较少,氮、钾元素亏缺会促进根对有机酸和酚酸物质的分泌.     

花生根分泌物的鉴定及其化感作用

采用改进的根系分泌物循环收集系统收集花生根系分泌物,利用气相色谱/质谱联用仪(GC-MS)鉴定其结构,并研究了花生根系分泌物对花生青枯病原菌的化感作用.结果表明,花生根系分泌物中主要含有丙三醇、苯甲酸、3,5-二甲基苯甲醛、苯乙酮、硬脂酸、棕榈酸和乳酸等7种物质.7种根系分泌物中只有苯乙酮在浓度低于0.1g·L-1时,对花生青枯病原菌生长才有明显的促进作用.同时还发现,苯乙酮浓度超过0.1 gL-1后对花生青枯病原菌有显著的抑制作用.这一结论为利用苯乙酮调控花生青枯病害的发生提供了可靠的依据.     

人参(Panax ginseng)根系分泌物成分对人参致病菌的化感效应

采用室内培养结合生物学测定的试验方法,研究了不同浓度人参(Panax ginseng)根系分泌物成分苯甲酸、邻苯二甲酸二异丁酯、十六酸和2,2-二(4-羟苯基)丙烷对人参立枯丝核菌(Rhizoctonia solani)、黑斑菌(Alternaria panax)、疫病菌(Phytophthora cactorum)、菌核菌(Sclerotinia schinseng)、锈腐菌(Cylindrocarpon destructans)和绿色木霉菌(Trichoderma viride)菌落生长及孢子萌发的化感效应.结果显示,不同浓度人参根系分泌物成分对人参致病菌及绿色木霉菌的化感效应存在显著差异.苯甲酸浓度与人参立枯丝核菌、菌核菌和锈腐菌菌落生长以及人参黑斑菌、锈腐菌孢子萌发呈负相关,与人参黑斑菌、绿色木霉菌菌落生长呈正相关;对人参疫病菌菌落生长的化感效应表现为低浓度和高浓度抑制,中浓度促进.邻苯二甲酸二异丁酯浓度与人参立枯丝核菌、黑斑菌、菌核菌和绿色木霉菌菌落生长以及人参黑斑菌孢子萌发呈负相关;对人参锈腐菌菌落生长和孢子萌发表现为低浓度和高浓度抑制,中浓度促进;对人参疫病菌菌落生长表现为低浓度和中浓度抑制,高浓度促进.2,2-二(4-羟苯基)丙烷浓度与人参立枯丝核菌、黑斑菌、疫病菌、绿色木霉菌菌落生长以及人参黑斑菌、锈腐菌孢子萌发呈负相关;对人参菌核菌、锈腐菌菌落生长表现中浓度促进,高浓度抑制.十六酸浓度与人参锈腐菌、疫病菌和绿色木霉菌菌落生长呈正相关,与人参锈腐菌孢子萌发呈负相关,对黑斑菌孢子萌发表现为中浓度抑制.4种根系分泌物的等量混合物浓度与人参致病菌及拮抗木霉菌菌落生长速率呈负相关.     

烟草青枯病劳尔氏菌与拮抗菌对根系分泌物的竞争作用

[目的]研究青枯病病原菌与拮抗菌的营养特性及其对烟草根系分泌物的响应差异,对提高拮抗菌定殖能力、有效生物防控烟草青枯病具有非常重要的意义。[方法]本研究通过筛选与鉴定贵州烟区青枯病病原菌株及拮抗菌株,通过Biolog表型芯片技术分别检测病原菌与拮抗菌的特征性碳、氮源,利用气质联用(GC-MS)检测烟草主栽品种K326根系分泌物的主要物质,在此基础上进行病原菌与拮抗菌对其利用能力、利用强度以及共培养的研究。[结果]经鉴定,分离、筛选到的病原菌株和拮抗菌株分别为青枯劳尔氏菌(Ralstonia solawacearum)和枯草芽孢杆菌(Bacillus subtilis);在含量为0.01μg/mL以上的根系分泌物中,12种物质的含量从高到低排序为:果胶>葡萄糖>木糖>阿拉伯糖>半乳糖>核糖>蔗糖>苯甲酸>果糖=D-甘露醇>棕榈酸>富马酸,果胶含量最高且明显高于其他物质;拮抗菌(LX4)对碳源利用能力高于病原菌(Rs)的碳源有阿拉伯糖、木糖和核糖,分别是病原菌利用能力的1.22、1.95和2.17倍;前12 h拮抗菌利用果糖强度高于病原菌,不同碳源共培养24 h后LX4对gfp-Rs(绿色荧光蛋白标记后的青枯病病原菌)抑制率为18.34%(阿拉伯糖)、53.23%(木糖)、63.53%(核糖)和52.09%(果糖)。[结论]拮抗菌对烟草根系分泌物的利用不及病原菌,但在特定碳源条件下拮抗菌能够利用根系分泌物中的某些碳源产生某种拮抗物质抑制病原菌,拮抗菌与病原菌之间同时存在利用性竞争和干扰性竞争关系,研究结果为进一步研究烟草青枯病的生物防控提供了新的理论依据。     

根系分泌物收集技术研究进展

根系分泌物在调控陆地生态系统根际微环境间的物质、能量和信息交流中具有重要作用.构建准确、适用的根系分泌物收集方法,对根系分泌物的种类、含量及其对环境变化的响应等信息的精准获取是理解植物根系-土壤界面生态过程与信息交流的关键环节和前提.目前,传统或新型的根系分泌物收集技术都致力于认知根系分泌物中化合物种类多样性和含量变化,但根系的生长高度依赖周围介质和生长环境,使根系分泌物的收集很难避开对根系本身的损伤、土壤颗粒对根系分泌物的吸附和释放,以及微生物代谢等因素的干扰,导致不同根系分泌物收集方法都存在各自的优缺点.本研究从室内收集和野外原位收集两方面系统综述了当前应用较广的一些传统和新型根系分泌物收集技术,并总结和比较了每种收集方法的优缺点;在此基础上,基于森林根际生态学过程野外原位研究的重要性和代表性,结合当前根系分泌物研究的不足,展望了未来森林根系分泌物野外原位收集技术构建中值得关注的3个重点方向,旨在为相关研究者开展根系分泌物收集与作用研究提供参考.     

嫁接茄根系分泌物与抗黄萎病的关系及其组分分析

探讨了嫁接对茄子土传病害黄萎病抗性的影响,采用浸根法收集茄子根系分泌物,并利用气-质联用技术检测了根系分泌物的组分和含量,测定了茄子根系分泌物及其模拟化感物质对黄萎菌菌丝生长的化感作用,分析嫁接后茄子根系分泌物的组成差异,探讨了嫁接茄抗病性与其根系分泌物成分的关系。结果表明:嫁接使茄子发病率显著降低。土壤黄萎菌数量随发育时期的推进而显著低于自根茄。嫁接茄根系分泌物对黄萎菌菌丝生长有一定的抑制作用。GC-MS检测结果显示,嫁接换根使茄子根系分泌物的组成成分发生一定的改变,嫁接根系分泌物中检测到了烃类、酯类、醇类、酚类、酮类、苯类和胺类物质,其中苯、醇和胺类在ZG中未检测到。但嫁接茄也缺少自根茄中检测到的炔类和菲啶。酚类公认的化感物质含量表现出自根茄大于嫁接茄。模拟物质对黄萎菌菌丝生长的影响表明:邻苯二甲酸二丁酯表现出在0.05 0.5 mmol.L-1浓度范围随浓度增加抑制作用增强,后随浓度增加抑制作用有所减弱。而豆蔻酸和棕榈酸均表现出随浓度增加先促进后抑制黄萎菌菌丝的生长。     

化感水稻PI312777苗期根系分泌物中化学成分分析

在接近自然栽培的田间土壤条件下,以无种植水稻秧苗的田间土壤为对照,采用循环法分别收集化感水稻品种PI312777(PI)苗期(3～4叶)根系分泌物和对照土壤溶液,经乙醚萃取,GC-MS分析和仪器谱图库(NIST98 & WILEY)检索.结果表明,在水稻PI根系分泌物的乙醚萃取物中检测到3个化合物,其中萜类9个(峰面积10.97%)、酚醌类8个(5.87%)、酯类个(10.8%)、醛酮类3个(1.44%)、杂环类4个(8.04%)、醇类2个(1.23%)、醚类2个(0.57%)和其他物质2个(1.20%),萜类之间、酚醌类之间的化合物结构具有明显的相似性.在对照土壤溶液的乙醚萃取物中检测到39个化合物,其中有7个化合物与水稻PI根系分泌物中化合物相同.此外,还讨论了水稻根系分泌物与对照土壤溶液之间物质的差异和各类物质的化感作用机理.     

转基因抗虫棉根系分泌物对棉花黄萎病菌生长的影响

转基因抗虫棉的抗病性下降已成为制约我国棉花生产的重要因素之一.以转基因抗虫棉及其亲本非转基因棉花对照为材料,研究转基因抗虫棉根系分泌物对棉花黄萎病菌孢子萌发和菌丝生长的影响,并对其根系分泌物中氨基酸及糖类的组成和含量进行了测定.结果表明：与亲本非转基因棉相比,2种转基因抗虫棉对棉花黄萎病菌的抗性下降,转基因抗虫棉的根系分泌物对黄萎病菌孢子萌发和菌丝生长均具有促进作用.与亲本常规棉中23相比,转基因双价抗虫棉中41根系分泌物中多了甲硫氨酸和赖氨酸,并且天冬氨酸、谷氨酸、丝氨酸、丙氨酸、缬氨酸、亮氨酸、酪氨酸的含量显著升高.泗棉三号与单价抗虫棉GK12的根系分泌物中虽然含有相同的氨基酸组分,但GK12的根系分泌物中酪氨酸、缬氨酸、亮氨酸的含量显著下降.中41根系分泌物中检测出4种糖类,而中23中仅检测出葡萄糖.抗虫棉GK12和泗棉三号根系分泌物中都检测出4种糖类,但其含量差异明显.     

香蕉抗(感)病品种根系分泌物对枯萎病菌和枯草芽孢杆菌的生物效应

为明确香蕉根系分泌物对枯萎病菌及其生防枯草芽孢杆菌的生物效应,采用离位溶液培养法收集抗枯萎病香蕉品种(南天黄)和感枯萎病香蕉品种(桂蕉6号)的根系分泌物,研究根系分泌物对土壤微生物种群数量、香蕉枯萎病菌和枯草芽孢杆菌生长的影响。结果表明: 抗病品种根系分泌物能显著减少土壤真菌的数量,抑制枯萎病菌孢子的萌发;而感病品种根系分泌物能显著促进病菌菌丝生长和孢子的萌发,两个品种根系分泌物均能显著促进枯草芽孢杆菌的生长和生物膜形成。经抗(感)病香蕉品种根系分泌物处理,病菌菌丝生长速率分别为11.28和12.28 mm·d^-1,病菌孢子的萌发率分别为34.6%和79.5%;枯草芽孢杆菌培养12 h后菌体生长量的OD₆₀₀分别为1.27和1.14,生物膜形成量在静置培养72 h后OD₅₇₀分别达1.11和1.30,两个品种处理间的差异均达显著水平。枯草芽孢杆菌在香蕉感病品种根际中定殖的菌量显著高于抗病品种。通过对两个品种根系分泌物中可溶性总糖、游离氨基酸和有机酸的含量和组成分析,发现抗病品种根系分泌物中有机酸和游离氨基酸的含量明显高于感病品种,在各组成成分中,以乙酸和脯氨酸在抗(感)病香蕉品种根系分泌物中含量比值较高,分别达3.7和2.4倍。综上所述,抗病品种根系分泌物能抑制病菌生长,感病品种根系分泌物则会显著促进病菌生长,而两个品种根系分泌物均能显著促进枯草芽孢杆菌的生长和生物膜的形成。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Physiological characteristics of various species of strains of carboxydobacteria

Seven strains of aerobic carbon monoxide-oxidizing bacteria (carboxydebacteria) when growing on CO as sole source of carbon and energy had doubling times which ranged from 12–42 h. The activity profiles obtained after discontinuous sucrose density gradient centrifugation indicated that the CO-oxidizing enzymes are soluble and the hydrogenases are membrane-bound in all strains examined. The CO-oxidizing enzymes of Pseudomonas carboxydohydrogena, Pseudomonas carboxydoflava, Comamonas compransoris, and the so far unidentified strains OM2, OM3, and OM4 had a molecular weight of 230,000; that of Achromobacter carboxydus amounted to 170,000. The molecular weights of the CO-oxidizing and H₂-oxidizing enzymes turned out to be identical. The cell sonicates were shown to catalyze the oxidation of both CO and H₂ with methylene blue, thionine, phenazine methosulfate, toluylene blue, dichlorophenolindophenol, cytochrome c or ferricyanide as electron acceptors. Methyl viologen, benzyl viologen, FAD⁺, FMN⁺, and NAD(P)⁺ were not reduced. The spectrum of electron acceptors was identical for all strains tested. Neither free formate, hydrogen nor oxygen gas were involved in the CO-oxidation reaction. Methylene blue was reduced by CO at a 1:1 molar ratio. The results indicate that CO-oxidation by carboxydobacteria is catalyzed by identical or similar enzymes and that the reaction obeys the equation CO+H₂OCO₂+2H⁺+2e^- as previously shown for Pseudomonas carboxydovorans.Dedicated to Otto Kandler remembering almost three decades of enjoyable cooperation     

Modulation of allostery of pyruvate kinase by shifting of an ensemble of microstates

Since the introduction of the concepts of allostery about four decades ago, much advancement has been made in elucidating the structure-function correlation in allostery. However, there are still a number of issues that remain unresolved. In this review we used mammalian pyruvate kinase (PK) as a model system to understand the role of protein dynamics in modulating cooperativity. PK has a triosephosphate isomerase (TIM)(α/β)₈ barrel structural motif. PK is an ideal system to address basic questions regarding regulatory mechanisms about this common (α/β)₈ structural motif. The simplest model accounting for all of the solution thermodynamic and kinetic data on ligand-enzyme interactions involves two conformational states, inactive E^T and active E^R. These conformational states are represented by domain movements. Further studies provide the first evidence for a differential effect of ligand binding on the dynamics of the structural elements, not major secondary structural changes. These data are consistent with our model that allosteric regulation of PK is the consequence of perturbation of the distribution of an ensemble of states in which the inactive E^T and active E^R represent the two extreme end states. Sequence differences and ligands can modulate the distribution of states leading to alterations of functions. The future work includes: defining the network of functionally connected residues; elucidating the chemical principles governing the sequence differences which affect functions; and probing the nature of mutations on the stability of the secondary structural elements, which in turn modulate allostery.     

（鱼句）亚科花（鱼骨）型鱼类骨骼系统的比较

对我国花型Hemibarbuspattern鱼类作了骨骼系统比较,结果表明,此类型鱼类脑颅较长,副蝶骨平直或稍弯曲,眶蝶骨腹纵嵴发达(铜鱼Coreius septentrionalis例外),下颞窝和咽突中等大,基枕骨后突发达;脑颅中的上筛骨的后突、侧筛骨的外筛突,蝶耳骨的外突、上耳骨的后突、围眶骨和后颞窝等均有明显的差异;咽颅中的舌颌骨、尾舌骨、鳃盖骨和下咽齿的列数等又有显著的区别;附肢骨骼中的腰带骨、脊椎骨中的复合神经骨和第4椎骨腹侧的悬器等也有不同之处。据此,这些差异和区别可作为属间或种间的分类依据。