ABA对枸杞体细胞胚发生的调节作用

Using Enzyme Linked Immunosorbent Assay (ELISA) method, we determined the ABA contents of different stages in somatic embryogenesis. The results showed that endogenous ABA contents increased to maximum value twice during somatic embryogenesis. After first maximum value of ABA contents embryogenic cells were observed in callus, and simultaneously, there was a specific protein of somatic embryogenesis investigated by SDS-PAGE. This protein accumulates preferentially in embryogenic callus but not in transferred callus. So it is suggested that ABA could promote the expression of specific genes and the synthesis of embryogenic protein during somatic embryogenesis in Lycium barbarum L. and ABA play an important role in globular stage as well. In addition, treatment of non-embryogenic activity callus with 4 mumol/L exogenous ABA could stimulate somatic embryogenesis. And the ABA function mechanism in relation to somatic embryogenesis was discussed.     

2,4-D浓度对花生体细胞胚发生的影响

选用丰花2号、鲁花11和农大818三个花生品种的胚小叶为外植体,在MSB培养基中分别添加不同浓度的2,4-D(1、5、10、15、20ms／L)作为诱导培养基,以MSB为继代培养基,研究2,4-D浓度对花生体细胞胚胎发生的影响。结果表明：2,4-D浓度对花生胚小叶脱分化及再分化有显著影响,低浓度的2,4-D对外植体脱分化有利,而较高浓度对再分化有利,诱导体细胞胚的最适2,4-D浓度为15mg／L。不同品种的体细胞胚诱导频率存在差异,丰花2号和农大818比鲁花11的体细胞胚诱导频率高;且丰花2号的成苗能力较强,在MSB培养基上即可成苗,鲁花11及农大818成苗能力较差。     

ABA对枸杞体细胞胚发生的调节作用

当枸杞的愈伤组织转入分化培养基后的第一天,内源ABA含量就大幅度增高,并成为胚性细胞分化和发育过程中的第一个峰值,也是最高峰值。这时也正是胚性细胞的启动分化期,从愈伤组织的切片明显可见胚性细胞的形成,同时SDS-PAGE结果也表明有相应的35KD蛋白质组分产生,而在未分化的愈伤组织中则未见该蛋白质组分。分化培养后的第15天,内源ABA含量达到第二个峰值,这时是球形胚形成时期,而35KD蛋白质组分含量也在此时达到最大值。外源ABA不仅可诱导内源ABA起始含量的升高,其含量峰值位于分化后的第一天和第15天,同时外源ABA可明显地提高体细胞胚发生的频率和质量。由此表明ABA含量的升高与胚性细胞的启动和发育密切相关,同时内源ABA与外源ABA对体细胞胚的发生有相同的促进作用。其作用机理可能是由于ABA直接或间接激活相关基因表达形成特异性胚性蛋白质组分,从而为胚性细胞的发生与发育奠定了分子基础。     

刺五加体细胞胚发生研究进展

综述了国内外对刺五加体细胞胚发生研究的现状。分别对刺五加体细胞胚发生方式、体细胞胚发育相关生理生化变化（包括生长素极性运输、DNA甲基化和代谢途径调控）、体细胞胚生物反应器培养的研究现状进行了评述。     

花楸合子胚诱导体细胞胚胎发生研究

分别以完整成熟胚、切去一个子叶的成熟胚和切下的子叶为外植体,以MS为基本诱导培养基、1/2MS为基本分化培养基,进行了花楸体细胞胚胎发生研究。结果表明:以完整合子胚作为外植体的体胚诱导率最高,为100%,最佳植物生长调节剂组合为5 mg.L-1NAA+2 mg.L-16-BA;NAA和6-BA浓度及二者的交互作用对愈伤组织和体胚诱导率的影响极显著;光照配合延长继代间隔时间有利于体胚发生。实体观察结果表明,花楸体胚发生方式有直接发生和间接发生两种;体胚发育经历了球形期、心形期、鱼雷形期和子叶期。组织学观察结果表明,体胚具有两极性,子叶期体胚结构完整。     

棉花体细胞胚发生机理的研究进展

棉花是一种较难通过体细胞胚发生完成植株再生的作物,而体细胞胚发生是限制棉花基因工程和细胞工程得以广泛应用的主要因素.研究者从不同角度探讨了棉花体细胞胚发生机理并取得了很大的进展,为棉花的遗传转化提供了重要的技术支持,同时成功建立了一些棉花植株再生体系.本文分别从基因型限制、胚胎学、生理生化变化、分子机理等方面阐述了近年来棉花体细胞发生机制的研究进展,并讨论了本研究领域目前存在的主要问题及相应对策.     

海边香豌豆胚性愈伤组织的诱导和体细胞胚发生

将生长１４ｄ的海边香豌豆（Ｌａｔｈｙｒｕｓ ｍａｒｉｔｉｍｕｓ（Ｌ．）Ｂｉｇｅｌ）无菌苗下胚轴切成０．５ｃｍ左右的片段,置于含有１ｍｇ／Ｌ２,４－Ｄ,０．５ｍｇ／Ｌ ＢＡ和０．５％ＮａＣｌ的ＭＳ培养基中,２８ｄ后诱导出胚性愈伤组织。将其转入含有适当浓度２,４－Ｄ的ＭＳ培养基上,又２８ｄ后可得到大量球形胚和心形胚以及极少量鱼雷胚和子叶胚。诱导体细胞胚适合的２,４－Ｄ浓度为０．５ｍｇ／Ｌ。较高浓度的２     

2,4-D诱导的花生体细胞胚发生的组织学研究

花生成熟胚胚叶在佃附加20mg/L 2,4-D的培养基上诱导20d后,转移至无激素培养基MS0继续培养,可获高频体细胞胚发生。组织学观察表明,体细胞胚起源于胚叶上表皮及表皮下数层细胞,这些细胞脱分化形成细胞质浓厚、细胞核大的胚性细胞团,胚性细胞团继续分裂形成体细胞胚。体细胞胚的发育过程经历球形胚、心形胚、鱼雷胚、子叶胚四个时期。     

Relationship between auxin-induced cell proliferation and somatic embryogenesis in culture of carrot cotyledons

We elucidated the relationship between cell proliferation and somatic embryogenesis in the culture of carrot cotyledons. Fresh weights of the cotyledon expiants were determined every five days while being cultured on a medium containing 2,4-D. Callus production increased exponentially from Day 20 to Day 25, showing a two-fold rate of proliferation. To examine the embryogenic potential of the callus, we pre-cultured cotyledon explants on an MS medium with 2,4-D, then transferred them to an MS basal medium at five-day intervals. Somatic embryos formed most frequently when the cotyledons were pre-cultured for 20 days on an MS medium that contained 5 μ2,4-D. The frequency of somatic embryo formation was 81%, while that of normal embryos with two cotyledons was 51% among those formed on a hormone-free medium. We used FACScan analysis to relate the embryogenic potential of the callus to the S phase in the cell cycle of cultured cells. The S phase was high after 25 days of culture on the medium with 5 μM 2,4-D. In contrast, the frequency of normal embryogenesis was higher at Day 20 of the pre-culture period. Culturing embryogenic calli on a medium with 5 μM 2,4-D was most favorable for producing somatic embryos with two cotyledons. We verified that active somatic embryogenesis was apparently related to cell division activity; somatic embryos induced from actively dividing cells were apt to accompany cotyledonary abnormality.     

植物激素对棉花体细胞胚胎发生的诱导及调节作用

选用11种激素研究了外源激素对棉花胚性愈伤组织增殖、胚胎发生和发育的调控作用。结果表明不同激素对棉花胚性愈伤组织增殖、胚胎发生与发育的影响不同。除2,4-D和BA对棉花胚性愈伤组织的增殖影响不大外,其他激素对棉花胚性愈伤组织的增殖均具有抑制作用,且具有一定的时间效应,同时还受基因型的影响。激素对棉花体细胞胚的形成和发育的影响极大,2,4-D既抑制了体细胞胚的形成,又抑制了体细胞胚的发育;TDZ的作用与2,4-D相似,显抑制了体细胞胚的形成,且诱导获得的体细胞胚均停留在球形胚阶段;GA也抑制了体细胞胚的形成,且不利于体细胞的成熟与萌发;BU-30对棉花体细胞胚形成与发育的影响不大。其他7类生长素类物质和细胞分裂素类物质对棉花体细胞胚的形成均具有促进作用,且依IBA、ABA、IAA、BA、KT、ZT、2iP序增强,其总胚数为对照的1．193—3．852倍;其中2iP的促进作用最大,可使产生的体细胞胚数提高2．852倍。     

枸杞体细胞胚发生过程中内源多胺代谢动态的研究

完全脱分化的枸杞继代愈伤组织在转入分化培养后第1天就开始启动分化,接着体细胞转变为胚性细胞,继而分裂形成多细胞原胚,球形胚和成熟胚等。与此同时,Put含量迅速上升形成第1个峰值,随后有所下降,但到多细胞原胚期Put含量又上升,并达到最高峰,为对照的6倍,Spd只在胚性细胞分化早期出现,Spm仅在体细胞胚发育晚期存在,外源Put不仅可提高体细胞胚发生频率,而且使3种内源多胺含量均有所提高,加入多胺生物合成抑制剂DFMA后,多胺水平下降,体细胞胚发生几乎完全被抑制。补充外源Put后,多胺的生物合成得到部分恢复,DFMA对体细胞胚发生的抑制效应也被部分解除。结果表明,维持一定量的多胺水平是枸杞体细胞胚发生的必要因素。     

一种新型的棉花体细胞胚胎发生的快速诱导法

用异常苗的茎段和叶片进行培养,可快速高效诱导获得棉花体细胞胚胎发生,激素组膈及其浓度配比影响异常苗的直接胚胎发生,在附加有０．１ｍｇ／Ｌ ＩＡＡ和０．１ｍｇ／ＬＺＴ的改良ＭＳ培养基上,异常苗不仅体细胞胚胎发生率高,而且形成的体细胞胚数目多,用异常苗作外植体获得胚性愈伤组织仅需要时间１０ｄ,获得成熟胚需要２０－３０ｄ,获得再生植株需要６０ｄ,大大短于常规方法获得胚性愈伤组织、体细胞胚和再生植株的时间     

皇冠草体细胞胚胎发生及其体胚发生过程中内源激素的变化

皇冠草是一种具有重要经济价值的大型观赏水草。以其幼叶为外植体,在MS培养基上,短期内(25d),直接诱导获得了体细胞胚。对不同的细胞分裂素及其不同组合的体胚诱导效应进行测试,发现：6-苄氨基嘌呤(6-BA,1mg/L)和玉米素(Zt,1mg/L)结合使用效果最好,诱导频率达100%,平均每个外植体可形成4.87个体细胞胚。当在含有Zt(1mg/L)的MS培养基中加入萘乙酸(NAA 0.5mg/L)时,外植体不能形成体细胞胚,而是形成大量的根。在含有吲哚乙酸(IAA,1mg/L)的MS培养基上,成熟的体胚5d后即可发育成完整的小植株。72%的小植株被成功地移栽到了水族箱中。采用HPLC法,对自外植体培养之日起到体胚发生和成熟的各个时期的内源激素含量进行了测定。发现各种内源激素的含量均不断增加,10d后达到对照的2倍左右。IAA含量在培养第10天时达到第一个峰值,第二个峰值出现在25d后;玉米素和玉米素核苷(Zt+ZR)含量在15d后达到最大值(为对照的8倍多),然后逐渐下降;赤霉素(GA-3)的变化趋势与细胞分裂素基本相同,但到体胚萌发时,其含量已恢复到对照水平;培养10d后的脱落酸(ABA)含量一直保持到了体胚成熟期。     

Development of a cyclic somatic embryogenesis regeneration system for leek (Allium ampeloprasum L.) using zygotic embryos

Summary In leek (Allium ampeloprasum L.) a cyclic system of somatic embryogenesis was developed. Somatic embryos used for cyclic embryogenesis were able to develop the same type of embryogenic callus as zygotic embryos in the primary cycle. For the first time a comparison of the efficiencies of both expiants was made. Ten families were investigated for somatic embryogenesis. There was a genetic relationship with respect to somatic embryo production between the reciprocal crosses. From each family one genotype was selected for investigating cyclic somatic embryogenesis. Different levels of somatic embryo production were found between the expiants of zygotic and somatic embryos. The two best genotypes, 92.001-03 and 92.002-33 produced twice as many somatic embryos as the overall average. On average, 56% of the somatic embryos finally developed into greenhouse plantlets.Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - BA 6-benzyladenine - MS medium Murashige and skoog (1962) basal medium     

火炬松组织培养研究和应用进展

从离体再生途径、影响因素、遗传转化、存在问题等方面对火炬松组织培养研究和应用进展作了介绍和讨论,以期对同类树种相关研究的开展提供参考。     

Morphogenetic and Histological Events during Somatic Embryogenesis in Intact Carrot Plantlets (Daucus carota L.) in Various Nutrient Media

It is shown that the induction of somatic embryogenesis neither requires the isolation of explants from intact carrot plants nor mechanical or chemical “wounding”.     

The effects of reduced nitrogenous compounds suggests that glutamine synthetase activity is involved in the development of somatic embryos in carrot

The addition of l-glutamine, -alanine or l-glutamic acid strongly stimulates somatic embryo formation in carrot, not only in the number of somatic embryos formed but also with respect to their development. The effects of the amino acids on somatic embryogenesis were stronger than that of ammonium ion. In particular, l-glutamine strongly stimulated the development of somatic embryos. To clarify the different effects of amino acids and ammonium ion, the activity of glutamine synthetase (GS; EC 6.3.1.2), a key enzyme involved in nitrogen assimilation, was measured. Its activity decreased during the later stages of embryo development.Abbreviations -Ala -alanine - Glu l-glutamic acid - Gln l-glutamine - 2,4-D 2, 4-dichlorophenoxyacetic acid - -GHA l-glutamic acid -monohydroxamate - GS glutamine synthetase - MS medium Murashige & Skoog (1962) medium - MS-NH₄ medium MS medium without NH₄NO₃ - MS+NH₄ medium MS-NH₄ medium with 10 mM NH₄Cl - MS+ala medium MS-NH₄ medium with 10 mM -alanine - MS+GLU medium MS-NH₄ medium with 10 mM l-glutamic acid - MS+GLN medium MS-NH₄ medium with 10 mM l-glutamine - NIR nitrite reductase - NR nitrate reductase