植酸在水稻（Oryza sativaL.）细胞培养中的促进作用

植酸（Ｃ６Ｈ１８Ｏ２４Ｐ６）添加到固体和液体培养基中,能显著降低多酚氧化酶活性,稳定培养基中ＰＨ值和ｍＶ值,并能促进水稻细胞生长,增强细胞抗褐化和水渍化能力,从而改善细胞状态。在培养基中植酸的最佳添加量为０．１％,配合使用ＭＥＳ可以增强其稳定ＰＨ值的效果。     

高压灭菌前后培养基pH值和渗透压的变化

配制马铃薯和N_6培养基,蔗糖浓度为9％,pH值为3—9(间隔0.5),渗透压分别为315mO_s(马铃薯培养基)和335mOs(N_6培养基)。经高压灭菌(120℃.1.5kg/cm~2·18分钟)后分别测量了各培养基的pH值和渗透压。高压灭菌前pH值低于4.5的培养基,其pH值在高压灭菌过程中升高;pH值越低,这种升高的趋势越明显。相反,高压灭菌前pH值高于5的     

植物组织培养因子与培养基中pH值的关系

MS培养基中添加不同种类和浓度的植物生长调节剂时,灭菌前后培养基中pH值均有一定幅度的下降,pH的变化值(△pH)为-0.2～-0.5,下降幅度因植物生长调节剂的种类和浓度而异;培养基中pH值随材料培养时间的延长而递减,降幅可达1.5,下降幅度与转接材料种类和多少也有关系.     

Hela细胞HGPRT缺陷型细胞系构建

建立稳定的次黄嘌呤鸟嘌呤磷酸核糖转移酶(HGPRT)缺陷的Hela细胞系,为细胞融合相关研究和人源化单克隆抗体制备提供有利于筛选的亲本细胞。通过诱变剂N-甲基-N′-硝基-N-亚硝基胍(MNNG)对Hela细胞进行诱变,逐步提高培养基中6-巯基鸟嘌呤(6-TG)的浓度,筛选出对6-TG稳定耐受的细胞,在次黄嘌呤-氨基喋呤-胸腺嘧啶(hypoxanthine-aminopterin-thymidine,HAT)培养基中鉴定其敏感性,最后对筛选得到的Hela-HGPRT-进行生物学鉴定。在此基础上,将Hela-HGPRT-细胞系与人淋巴细胞融合,在HAT培养基中筛选杂交细胞。筛选得到了能够长期在含20μg/mL 6-TG培养基中生长的Hela-HGPRT-细胞,并且在HAT培养基中不能存活。Hela-HGPRT-细胞与人淋巴细胞成功融合,获得能够连续传代培养的杂交瘤细胞。经MNNG诱导和6-TG筛选,得到了稳定传代的Hela-HGPRT-细胞系,该细胞系可用于细胞融合相关研究。     

植酸对红豆杉细胞悬浮培养影响作用的研究

针对红豆杉细胞培养中经常遇到的褐变问题,以植酸做抗氧化剂,添加到悬浮细胞培养基中,能提高细胞鲜重,明显抑制细胞多酚氧化酶和过氧化物酶活性,从而有效地控制细胞褐变,促进红豆杉悬浮细胞生长。以005%浓度的添加效果最好。     

大白菜无菌苗叶肉原生质体植株再生

商用大白菜叶肉原生质体,经液体培养基浅层培养,再生细胞分裂．并获得愈伤组织。愈伤组织转到分化培养基上诱导分化,已从城青2号大白菜叶肉原生质体得到再生的完整植株。再生细胞的分裂额率与培养基中的激素种类和浓度有关,受原生质体培养浓度的影响。多胺类物质[亚精胺(SPD)]的加入,可促进细胞分裂,井有益于以后植株的再生。通过提高新鲜培养液的pH值(6．5)可使细胞团的褐化得到明显的控制。在植株分化过程中,培养基中低浓度(1．1％)的蔗糖与植株分化有关。     

不同因素对岩黄连悬浮细胞生长的影响

目的:建立一个快速生长的岩黄连悬浮细胞培养体系。方法:研究了接种量、基本培养基、初始pH值、不同碳源对岩黄连悬浮细胞生长的影响。结果:合适的接种量是7.5~10%(FW),接种量过少会抑制细胞生长;B5和MS基本培养基均适合岩黄连细胞的生长;最佳初始培养基pH值为6.0,此时获得的细胞生物量最高;岩黄连悬浮细胞培养的生长周期为24d,最大生物量出现在第18d,达到14.1g/l(DW);蔗糖比葡萄糖更有利于岩黄连细胞的生长,添加60g/l蔗糖所获得的生物量最高,达到18.5g/l(DW)。     

pH对槐角愈伤组织黄酮类化合物产量的影响

培养基酸碱度是影响植物生长和次生代谢的重要因素之一。将生长稳定的国槐槐角愈伤组织在不同pH值的B5悬浮培养基中培养,比较其生长状况、生物量及苯丙氨酸转氨酶活性和黄酮类化合物的产量。结果表明:pH为6.6时,国槐细胞生长状况好,且不同pH下的苯丙氨酸转氨酶活性差异显著;培养基呈弱酸性(即6.6±0.05)时,细胞黄酮类化合物含量较高。综合生长天数和产量,最佳的收获时期为继代后的第25～30天。     

植酸钠对黑曲霉柠檬酸发酵产酸的促进效应

研究了植酸钠对黑曲霉柠檬酸发酵产酸的促进效应。在葡萄糖全合成培养基中添加１％的植酸钠,可使产酸比对照提高２．４倍;在薯粉、玉米粉等天然培养基中添加１％植酸钠,柠檬酸产量分别提高１．７倍和１．３倍。酶活性测定分析表明,植酸钠对柠檬酸代谢途径中的几种关键酶的活性有影响。     

植物组织培养简报摘编

植物材料、外植体培养条件结　　果作者 (单位 )盾叶薯蓣(Dioscoreazin giberensis)幼根　　基本培养基含大量元素减半的MS无机盐、肌醇 10 0、烟酸 1.0、VB1 1.0、VB6 1.0、蔗糖2 0 .0 g·L- 1 和琼脂 8.0 g·L- 1 。( 1)愈伤组织诱导培养基添加6 BA 0、0 .5、1.0、2 .0和NAA0 .5、1.0、2 .0或 2 ,4 D 0 .5、1.0、2 .0 ;( 2 )不定芽分化培养基添加NAA 0、0 .2和 6 BA 1.0、2 .0、4.0、5 .0 ;( 3 )不定芽增殖培养基为 6 BA 2 .0 +NAA 0 .2 ;( 4 )生根培养基中添加IBA2 .0。所有培养基的 pH值均为5 .8。培养温度为 ( 2 5± 2 )℃…     

不同条件对植物中间纤维体外装配的影响(简报)

细胞骨架的研究是当今细胞生物学中最为活跃的领域之一,而中间纤维是三种主要骨架纤维中研究较少的一种。从60年代发现至今,人们对动物细胞中间纤维的研究已经比较深入,近来又发现它在基因表达等重要生命活动中起一定的作用。中间纤维有一个显著的特征,就是能够在体外进行自我装配,不需要核苷酸和结合蛋白参加,也不依赖于蛋白质的浓度。植物细胞中是否存在中间纤维一直是未解决的问题。从80年代起,有一些研究发现在高等植物细胞中存在能与动物细胞中间纤维抗体进行     

用ribozyme抑制增殖细胞核抗原的表达对HaLa细胞增殖的影响

增殖细胞核抗原(PCNA)是DNA聚合酶δ的辅助蛋白,它是细胞染色体DNA复制所必需的。人工设计的ribozyme具有可特异地切割PCNA mRNA的性质,将此ribozyme的自修剪体内表达质粒导入HeLa细胞,从细胞总RNA中分离相应部分能在体外切割靶RNA片段,证明此表达质粒在细胞内能表达出有活性的ribozyme分子。与对照相比,导入ribo-zyme表达质粒的HeLa细胞进入S期的时间从12 h推迟到20 h,而突变ribozyme的对照表明反义抑制对细胞进入S期的影响较小(推迟到15 h)。证明该ribozyme能有效抑制He-La细胞DNA复制,同时亦证明PCNA对于细胞DNA复制及细胞周期进程的重要性。     

pH影响Ca~(2 )和EGTA对水霉(Saprolegnia ferax)菌丝顶端生长的作用效应

水霉(Saprolegia ferax)菌丝在pH6.0-8.0的OM液体培养基中生长良好,在pH5.0时生长速率有所下降,在pH3.0—4.0时停止生长。短时间(30min)作用研究表明,低浓度的CaCl_2促进pH5.0(1—5mmol/L)和pH6.0(1mmol/L)条件下的菌丝顶端生长,抑制pH7.0—8.0条件下的菌丝生长。1mmol/L以上的EGTA则抑制pH5.0条件下菌丝顶端生长,促进pH6.0—8.0条件下的菌丝顶端生长。但CaCl_2和EGTA都不能使pH3.0—4.0条件下的菌丝恢复生长。长时间(8h)作用跟踪观察表明,2mmol/L EGTA(pH6.8)短时间作用可促进菌丝生长,但随着培养时间延长,则产生抑制作用,并诱导原生质从菌丝最顶端喷出。说明细胞壁Ca~(2 )起着提供胞外Ca~(2 )源和细胞壁修饰成分的双重作用。Ca~(2 )通道阻断剂verapamil对菌丝顶端生长的抑制作用也说明顶端生长所需的Ca~(2 )来自胞外。     

db-cAMP对转化细胞钙调素基因表达与细胞骨架的影响

转化的C_3H_(10)T_(1/2)细胞表现增殖速度加快、表面微绒毛增加,细胞变圆,叠层生长,ConA受体呈帽状分布,微管、微丝、纤粘蛋白分布明显减少。与增殖有关的癌基因c-fos表达增强,同时发现与细胞增殖、转化和细胞骨架调节有关的钙调素(CaM)基因表达加强。用1mmo/Ldb-cAMP处理转化细胞,观察到CaM基因和原癌基因c-fos的表达分别在处理后1小时和2小时急剧下降。处理后4—5天,转化细胞表型趋正常化,大部分细胞恢复单层生长。细胞表面微绒毛和泡状物减少,ConA受体帽状分布消失,恢复分散分布在细胞膜上的特点。细胞生长明显被抑制,用优先在G_1期表达的4F_1 cDNA为探针进行分子杂交,证实了经db-cAMP处理后的细胞被阻抑在G_1期。经db-cAMP处理6天的转化细胞中微管、微丝、纤粘蛋白基本恢复正常分布。实验表明CaM的表达增强与转化细胞表型变化和细胞骨架组装减弱密切相关,db-cAMP作用后CaM表达下降是抑制转化细胞增殖并使细胞表型和细胞骨架分布趋于正常的关键事件之一。     

IL-1诱导小鼠胸腺上皮细胞(MTEC1)克隆分泌化学趋化因子

通过将本室所建小鼠胸腺上皮细胞系MTEC1进行克隆,获得由单一细胞来源的12个MTEC1-DW细胞克隆,检测各克隆分泌IL-1,IL-6及CF活性,分析诱导MTECl-DW细胞克隆分泌CF的因素.选择不分泌IL-1及CF的MTEC1-DW克隆,于细胞培养中加入外源IL-1或/及IL-6,分析其细胞培养液中CF活性;选择分泌高活性IL-1及CF的MTEC1-DW克隆,于细胞培养中加入抗IL-1mAb,阻断IL-1活性,分析其细胞培养液中CF活性.结果显示IL-1能诱导MTEC1-DW细胞克隆分泌CF,IL-6的这种作用则很微弱.     

培养条件对三角帆蚌外套膜离体上皮组织珍珠质分泌能力的影响（简报）

珍珠是由珍珠贝外套膜的上皮细胞受到外源刺激物刺激形成珍珠囊（pearl—sac）,并由珍珠囊产生的钙质分泌物．其分泌物逐渐包围刺激原．使之体积急剧增长而形成的,珍珠质（nacre）是由大于95％的碳酸钙晶体与约5％的角壳蛋白组成的生物矿化产物。因此珍珠贝的外套膜在珍珠形成中起着重要的作用。珍珠贝外套膜的体外培养已开展了一些初步的研究工作。     

真菌激发子对人参悬浮培养细胞的生长和人参皂甙生物合成的影响

真菌诱导子处理人参悬浮培养细胞后,人参皂甙的合成有明显增加,诱导处理改变人参皂甙的积累时程,促进人参细胞培养物中次生产物的外泌,同时增强细胞对蔗糖的摄取、吸收并引起细胞H~ 流的变化。     

ON THE NATURE OF THE DYE PENETRATING THE VACUOLE OF VALONIA FROM SOLUTIONS OF METHYLENE BLUE

When uninjured cells of Valonia are placed in methylene blue dissolved in sea water it is found, after 1 to 3 hours, that at pH 5.5 practically no dye penetrates, while at pH 9.5 more enters the vacuole. As the cells become injured more dye enters at pH 5.5, as well as at pH 9.5. No dye in reduced form is found in the sap of uninjured cells exposed from 1 to 3 hours to methylene blue in sea water at both pH values. When uninjured cells are placed in azure B solution, the rate of penetration of dye into the vacuole is found to increase with the rise in the pH value of the external dye solution. The partition coefficient of the dye between chloroform and sea water is higher at pH 9.5 than at pH 5.5 with both methylene blue and azure B. The color of the dye in chloroform absorbed from methylene blue or from azure B in sea water at pH 5.5 is blue, while it is reddish purple when absorbed from methylene blue and azure B at pH 9.5. Dry salt of methylene blue and azure B dissolved in chloroform appears blue. It is shown that chiefly azure B in form of free base is absorbed by chloroform from methylene blue or azure B dissolved in sea water at pH 9.5, but possibly a mixture of methylene blue and azure B in form of salt is absorbed from methylene blue at pH 5.5, and azure B in form of salt is absorbed from azure B in sea water at pH 5.5. Spectrophotometric analysis of the dye shows the following facts. 1. The dye which is absorbed by the cell wall from methylene blue solution is found to be chiefly methylene blue. 2. The dye which has penetrated from methylene blue solution into the vacuole of uninjured cells is found to be azure B or trimethyl thionine, a small amount of which may be present in a solution of methylene blue especially at a high pH value. 3. The dye which has penetrated from methylene blue solution into the vacuole of injured cells is either methylene blue or a mixture of methylene blue and azure B. 4. The dye which is absorbed by chloroform from methylene blue dissolved in sea water is also found to be azure B, when the pH value of the sea water is at 9.5, but it consists of azure B and to a less extent of methylene blue when the pH value is at 5.5. 5. Methylene blue employed for these experiments, when dissolved in sea water, in sap of Valonia, or in artificial sap, gives absorption maxima characteristic of methylene blue. Azure B found in the sap collected from the vacuole cannot be due to the transformation of methylene blue into this dye after methylene blue has penetrated into the vacuole from the external solution because no such transformation detectable by this method is found to take place within 3 hours after dissolving methylene blue in the sap of Valonia. These experiments indicate that the penetration of dye into the vacuole from methylene blue solution represents a diffusion of azure B in the form of free base. This result agrees with the theory that a basic dye penetrates the vacuole of living cells chiefly in the form of free base and only very slightly in the form of salt. But as soon as the cells are injured the methylene blue (in form of salt) enters the vacuole. It is suggested that these experiments do not show that methylene blue does not enter the protoplasm, but they point out the danger of basing any theoretical conclusion as to permeability on oxidation-reduction potential of living cells from experiments made or the penetration of dye from methylene blue solution into the vacuole, without determining the nature of the dye inside and outside the cell.     

INFLUENCE OF TEMPERATURE AND HYDROGEN ION CONCENTRATION UPON THE SPORE CYCLE OF BACILLUS SUBTILIS

1. At 5°C. no germination took place. 2. At 25°C. and at 37°C. germination occurs if the hydrogen ion concentration of the broth is kept between pH 5 and pH 10, but not at higher or lower pH values. 3. The completion of the spore cycle likewise requires a hydrogen ion concentration between pH 5 and pH 10. 4. The spores can germinate when the pH value is 10, although after germination the vegetative cells multiply only to a very slight extent and soon pass into spores. 5. The slight growth and multiplication of vegetative cells in broth of pH 10 suggest that the formation of endospores in this medium must be caused largely by the unfavorable reaction of the medium rather than by the accumulation of metabolic products. 6. Automatic adjustment of the medium seems to play a rôle in the completion of the spore cycle. 7. The results are not only of theoretical importance but they have a practical application to the preservation of food by canning and by other methods.     

AMPHOTERIC COLLOIDS : IV. THE INFLUENCE OF THE VALENCY OF CATIONS UPON THE PHYSICAL PROPERTIES OF GELATIN.

1. A method is given by which the amount of equivalents of metal in combination with 1 gm. of a 1 per cent gelatin solution previously treated with an alkali can be ascertained when the excess of alkali is washed away and the pH is determined. The curves of metal equivalent in combination with 1 gm. of gelatin previously treated with different concentrations of LiOH, NaOH, KOH, NH₄OH, Ca(OH)₂, and Ba(OH)₂ were ascertained and plotted as ordinates, with the pH of the solution as abscissæ, and were found to be identical. This proves that twice as many univalent as bivalent cations combine with the same mass of gelatin, as was to be expected. 2. The osmotic pressure of 1 per cent solutions of metal gelatinates with univalent and bivalent cation was measured. The curves for the osmotic pressure of 1 per cent solution of gelatin salts of Li, Na, K, and NH₄ were found to be identical when plotted for pH as abscissæ, tending towards the same maximum of a pressure of about 325 mm. of the gelatin solution (for pH about 7.9). The corresponding curves for Ca and Ba gelatinate were also found to be identical but different from the preceding ones, tending towards a maximum pressure of about 125 mm. for pH about 7.0 or above. The ratio of maxi mal osmotic pressure for the two groups of gelatin salts is therefore about as 1:3 after the necessary corrections have been made. 3. When the conductivities of these solutions are plotted as ordinates against the pH as abscissæ, the curves for the conductivities of Li, Na, Ca, and Ba gelatinate are almost identical (for the same pH), while the curves for the conductivities of K and NH₄ gelatinate are only little higher. 4. The curves for the viscosity and swelling of Ba (or Ca) and Na gelatinate are approximately parallel to those for osmotic pressure. 5. The practical identity or close proximity of the conductivities of metal gelatinates with univalent and bivalent metal excludes the possibility that the differences observed in the osmotic pressure, viscosity, and swelling between metal gelatinates with univalent and bivalent metal are determined by differences in the degree of ionization (and a possible hydratation of the protein ions). 6. Another, as yet tentative, explanation is suggested.