细胞壁结合的β—葡聚糖酶对百合花粉管顶端生长的调节作用

从离体培养的麝香百合（Lillum longiforum Thunb.)花粉管细胞壁中分离纯化出β－葡聚糖酶。抑制剂野尻酶素（mojirimycin)使该酶活性明显降低。若在百合花粉培养的初始或培养1h时加入3mmol/L野尻酶素,与对照相比较,花粉的萌发率分别抑制99．6％和91.4％。若把3mmol/L野尻酶素分别在培养的不同时刻（0、1、1．5和2h）加入到液体培养基中,花粉管的生长都即刻受阻。此后,花粉管生长方向稍有改变,且花粉管直径略增,呈弯曲的非正常形态。用视频显微术跟踪记录在正常或含有不同浓度野尻酶素（0.003、0．03、0．3和3mmol/L）的半固体培养粉管直径、胞质内细胞器及囊泡的分布和顶端生长区的区域范围也呈现异常。野尻酶素对花粉管生长的抑制是可逆转的。这些结果表明,β－葡聚糖酶参与百合花粉的萌发和花粉管生长的调节。结合我们已报道的该酶的性质及作用方式,进而推测该酶通过降解1,3－1／1,4－或1,3：1,4－β－葡聚糖,影响细胞壁的延展性,从而对花粉管顶端生长显示调节作用。     

蛋白酶体抑制剂MG132对青扦花粉萌发和花粉管生长的影响

泛素／蛋白酶体系统（UPP）是真核细胞内蛋白质选择性降解的主要途径,而蛋白酶体是UPP中蛋白质降解的场所。本文应用细胞学、统计学方法以及FTIR技术研究了蛋白酶体抑制剂MG132对青扦（Pecea wilsonii）花粉萌发、花粉管生长的影响。结果表明：MG132显著抑制青扦花粉萌发和花粉管生长,并导致花粉管形态异常,主要表现为花粉管亚顶端出现液泡化,并且液泡随着培养时间的延长而扩大到整个花粉管,花粉管濒临死亡;而DMSO以及非蛋白酶体抑制剂E-64不产生类似结果;半薄切片结果表明,MG132处理后不仅花粉管细胞质发生液泡化,生殖细胞也发生液泡化;FTIR分析进一步表明,MG132处理后,花粉管顶端的细胞壁蛋白和果胶质含量大幅度下降。上述结果表明：MG132通过抑制蛋白酶体活性显著影响青扦花粉萌发及花粉管生长;UPP在青扦花粉萌发、花粉管极性生长模式的建立和维持过程中起重要作用;抑制蛋白酶体活性将导致青扦花粉管的程序性死亡。     

丝状真菌的顶端生长及与细胞壁关系研究进展

丝状真菌菌丝的生长,与其它植物极性细胞（如花粉管、根毛等）生长一样,以细胞的顶端生长为特征（17,’7）,其生长仅限十菌丝顶端的穹窿区域,在直径均匀的后部管状区域则几乎不再伸长。菌丝的顶端生长方式在一个世纪前已被发现（”）,随后的研究对此进行了进一步阐述,指出菌丝的生长速率在顶端最大,距顶lpm处壁的合成速率可能是50Pm处的50倍（12）,而在伸长区的基部,生长速率可能降为零（’7〕。菌丝的顶端生长是多种因素造成的,包括泡囊、肌动蛋白、膨压、细胞壁等（12）,其中最主要的影响来自于菌丝细胞壁。菌丝细胞壁的成分…     

PLC—IP3信号途径参与花粉管伸长调控的显微注射实验

以百合（Ｌｉｌｉｕｍ ｄａｖｉｄｉｉ Ｄｕｃｈ．）花粉为材料,通过显微注射肌醇磷脂信使系统中重要组成成分或其抗体,研究该信使系统牟花粉管伸长的影响。发现显微注射动物来源磷脂酶Ｃ（ＰＬＣ）β１－３抗体显著抑制花粉管的伸长生长,而注射ＰＬＣβ４抗体对花粉管伸长无影响;显微注射三磷酸肌醇（ＩＰ３）,可显著促进花粉管伸长生长;显微注射动物来源的ＩＰ３Ｒ２、ＩＰ３Ｒ３抗体可显著抑制花粉管伸长生长,而注射ＩＰ     

金鱼草花粉管亚原生质体的分离及在培养中的行为

应用酶法从金鱼草花粉管中分离出大量的亚原生质体。这种亚原生质体培养在 D_2液体培养基中,不论是有核的或是无核的都能再生厚的细胞壁和生长出花粉管状的管状结构。这些管状结构除了它们的顶端区外也沉积厚的细胞壁。随着管状结构的生长,内含物逐渐移向管状结构的顶端。当生长停止后,内含物可能完全被耗尽;有时管状结构的顶端破裂,内含物释放至培养液中。无核和有核亚原生质体同样显示有正常花粉管的基因表达的特性,即在培养中有类似花粉管生长的行为。这一事实表明在萌发的花粉管中有预先合成的 mRNA 的存在。     

蛋白酶体抑制剂MG132对青扦花粉萌发和花粉管生长的影响

泛素/蛋白酶体系统(UPP)是真核细胞内蛋白质选择性降解的主要途径,而蛋白酶体是UPP中蛋白质降解的场所。本文应用细胞学、统计学方法以及FTIR技术研究了蛋白酶体抑制剂MG132对青扦(Peceawilsonii)花粉萌发、花粉管生长的影响。结果表明:MG132显著抑制青扦花粉萌发和花粉管生长,并导致花粉管形态异常,主要表现为花粉管亚顶端出现液泡化,并且液泡随着培养时间的延长而扩大到整个花粉管,花粉管濒临死亡;而DMSO以及非蛋白酶体抑制剂E-64不产生类似结果;半薄切片结果表明,MG132处理后不仅花粉管细胞质发生液泡化,生殖细胞也发生液泡化;FTIR分析进一步表明,MG132处理后,花粉管顶端的细胞壁蛋白和果胶质含量大幅度下降。上述结果表明:MG132通过抑制蛋白酶体活性显著影响青扦花粉萌发及花粉管生长;UPP在青扦花粉萌发、花粉管极性生长模式的建立和维持过程中起重要作用;抑制蛋白酶体活性将导致青扦花粉管的程序性死亡。     

硼对吲哚乙酸在植物体内运输的影响

以绿豆为指示作物,研究缺硼对侧芽生长及³H-吲哚乙酸（IAA）在完整植株体内运输的影响.结果表明：缺硼诱导侧芽生长,导致³H-IAA移动峰靠近植株顶端,茎中³H-IAA的放射性活度也低于供硼充分的植株,说明缺硼抑制了³H-IAA在植株体内的极性运输;无论缺硼与否侧芽中均未检测到³H-IAA,所以侧芽的生长与³H-IAA在其中的积累没有关系,表明硼并不是通过调节IAA在侧芽中的积累,而是通过调节IAA在主茎的移动流调控侧芽生长;给缺硼植株供硼24 h能够恢复IAA在植株体内的极性运输能力.     

硅对盐胁迫下枣树组织培养苗细胞壁形成和相关酶活性的影响

盐胁迫（75mmol·L^-1 NaCl）下,枣树微茎段外植体成活率、生根率及枣苗的侧根条数和长度、苗高、单株重量均较对照显著减小;盐胁迫下加硅（Si）（0．75mmol·L^-1 KSiO3）,枣苗的前述指标与对照无显著性差异。盐胁迫下,枣组织培养生根苗细胞壁提取率显著下降,细胞壁中蛋白和低分子量果胶含量显著降低,EDTAU溶性果胶和碱溶性果胶含量显著提高,半纤维素和纤维素含量降低;盐胁迫下加Si,枣苗细胞壁提取率显著提高,细胞壁主要戍分的含量水平与对照相近。与盐胁迫下相比,盐胁迫下加Si,虽然枣苗果胶甲酯酶（PME）和多聚半乳糖醛酸酶（PG）活性升高未达显著性差异水平,但纤维素酶（Cx）活性显著降低,3种水解酶活性的比值均显著增大,细胞壁共价结合态H^＋-ATP酶活性显著升高。结果说明,提高培养基可溶性Si水平,可显著改善受盐胁迫枣苗细胞壁水解酶的活性平衡、组分含量的均衡及细胞壁内外溶质的适应性分配,从而为枣苗较好生长奠定了基础。     

Ca~(2+)参与水霉菌丝细胞壁修饰的证据

以细胞壁崩溃酶－Driselase短时间处理水霉（Saprolegniaferax）菌丝,pH5．0时可使原生质从菌丝亚顶端喷出,pH6．0～8．0时则不导致该现象发生;适当浓度EGTA的存在,可提高pH5．0时酶解引起的原生质喷出频率、使pH6．0～8．0时生长菌丝的顶端原生质也喷出、并且喷出多发生在菌丝最顶端。外加CaCl2不抑制菌丝顶端原生质的喷出,排除了Ca2+抑制酶活性的可能。随后的跟踪观察显示,长时间以缺Ca2+培养介质培养菌丝,同样能够导致菌丝顶端原生质喷出。上述研究结果表明,培养介质中Ca2+和H+对菌丝完整性的维持起调节作用,细胞壁上的Ca2+可能参与了水霉菌丝细胞壁物理特性的修饰。     

花粉管细胞壁结构及胞质运动

花粉管的极性顶端生长是将雄配子体运输到子房的过程,在高等植物有性生殖过程中起着重要的作用。花粉管的生长过程包括许多方面,其中最为重要的是花粉管细胞壁的合成和胞质运动。本文就细胞壁的结构及组成,生殖细胞和营养核的移位,细胞器以及分泌小泡的运动等方面作了较全面论述。     

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.     

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.     

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.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

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。     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.     

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.