植物细胞内产物释放行为研究进展

本文介绍了植物细胞培养中胞内产物释放的研究现状,包括：１、化学法：（１）有机溶剂法,（２）抗生素法,（３）蛋白质、溶血卵磷脂、脱乙酰几丁质,（４）去污剂、螯合剂;２．物理法：（１）渗透压冲击,（２）温度冲击,（３）电处理,（４）超声波处理、激光打孔,３、ｐＨ扰动及生物碱在胞内积累的两种机理。     

植物细胞培养生产天然产物的研究进展

植物细胞培养技术已成为工业化生产天然产物的一条新途径。本文概述了植物细胞悬浮培养和固定化植物细胞系统生产天然产物的研究进展,介绍了植物细胞培养的产物,提高产物产量的途径和培养系统等方面的研究动态,讨论了目前存在的问题以及未来的发展趋向。     

化学法研究长春花细胞胞内产物释放行为

对不同生理状态下细胞对外界刺激的反应情况进行了比较;研究了EDTA、氮酮、甲壳素做为长春花细胞渗透剂所使用的条件;探讨了它们影响胞内产物释放的短期效应、长期效应及长时间处理所造成的叠加效应。     

提高植物培养细胞中次级代谢产物含量的途径

利用植物细胞培养的方法可以取代人工栽培、天然采集或人工合成的方法大量生产很多具有价值的产物(如药品、农药、香料、色素及食品添加剂等)。目前,利用紫草(Lithospermum erythrochizon)培养细胞生产紫草素,利用人参(Panax ginseng)根培养物生产食品添加剂等已进入商业市场。另外,利用黄连(Coptisjaponica)培养细胞生产小蘗碱、利用长春花(Catharathus roseus)培养细胞生产蛇根碱及阿吗碱和利用毛地黄(Digitalis lanata)培养细胞生产地高辛等亦都进行了工业化生产。尽管这样,由于植物培养细胞亦存在着一些缺点如很多培养物中代谢物含量很低或不存在,生长速度缓慢加上目前发酵成本过高、很多关键性问题未解决等等,使之未能广泛地应用于工业化生产。近年来,为了解决上述诸问题特别是解决培养物中代谢物含量低的问题,各国科研人员进行了不懈的努力,取得了长足的进展。本文着重对这方面近年来采用的新方法及新技术的研究作一概述。     

植物细胞培养生产天然产物的前景

早在1902年,哈伯兰特(Haberlandt)提出了植物细胞全能性的理论,即单个植物细胞,在适宜的条件下,具有发育成完整植株的潜力。直到1934年,怀特(white)首次由番茄根建立了第一个活跃生长的无性繁殖系。随后植物细胞在液体培养基中悬浮培养获得了成功,从而建立了植物细胞培养。1950年邦纳(Bonner)等开创了银胶菊愈伤组织中橡胶生物合成的研究。1956年鲁蒂因(Routin)和尼克尔(Nickell)首次提出了利用植物细胞培养生产天然产物的专利申请报告。从此植物细胞     

植物培养细胞的形态分化与次生代谢产物的生产

植物培养细胞的形态分化与次生代谢产物的生产张泓（西北大学生物系西安７１００６９）ＭＯＲＰＨＯＬＯＧＩＣＡＬＤＩＦＦＥＲＥＮＴＩＡＴＩＯＮＯＦＣＵＬＴＵＲＥＤＰＬＡＮＴＣＥＬＬＳＡＮＤＴＨＥＰＲＯＤＵＣＴＩＯＮＯＦＳＥＣＯＮＤＡＲＹＭＥＴＡＢＯＬＩＴＥ...     

植物生物技术讲座（五）：植物细胞大量培养技术及次生代谢产物的生产

植物生物技术讲座（五）──植物细胞大量培养技术及次生代谢产物的生产秦明波（北京师范大学生物学系１００８７５）云月（北京植物细胞工程实验室１０００８１）几世纪以来,植物早已成为化学品的一个重要资源,尤其在制药和食品工业方面更是不可缺少。可是随着生态环境...     

植物细胞次级代谢产物生产条件的调控

概述了培养基成分,供氧情况,诱导子,PH值和生物反应器的类型对植物细胞次生代谢物的产量及质量的影响。介绍了此研究领域的发展趋势及存在问题。     

诱导剂对植物细胞培养生产次生代谢物的作用

诱导剂可以诱导植物产生植物抗毒素,因此成为植物细胞培养次生代谢物生产中提高产量的一种手段。本文介绍了有关诱导剂在植物细胞生产次生代谢物方面的研究概况,重点介绍了诱导剂的作用机理及第二信使的研究成果。     

油菜游离细胞培养及易再生的体细胞无性系的建立

以芥菜型油菜(Brcssica juncea)下胚轴来源的愈伤组织为材料,进行悬浮细胞振荡培养,得到游离的单细胞。这些细胞作浅层液体静置培养,可获得高频率的愈伤组织。在附加有水解乳蛋白200毫克/升、BA 2—3毫克/升及GA,0.1—1毫克/升的MS培养基上,这些愈伤组织分化了芽。分化的芽在无激素或附加有0.01—0.1毫克/升IAA或NAA的MS培养基上长出根,从而发育成完整植株。当对游离细胞获得的再生植株的茎切段愈伤组织,再经上述程序进行细胞培养时,发现愈伤组织诱导率及愈伤组织分化频率均远远高于原供体,从而建立了B.juncea易再生的体细胞无性系。     

植物抗虫性次生物质的研究概况

综述了国内外与植物抗虫性有关的次生物质的主要类型和植物次生物质对昆虫的寄主选择、取食和产卵等作用的研究进展,对次生物质在生态系统中的作用也作了介绍,并展望了植物次生物质的应用前景。     

植物抗寒性研究进展

低温是限制植物生长和分布的一种非生物胁迫因素。因此,提高植物的抗寒性对农业具有十分重要的意义。综述了植物抗寒性的最新进展,包括植物抗寒性机理研究,提高植物抗寒力的方法研究和应用情况;提出了在植物抗寒性研究中存在的问题,并对未来工作重点进行了展望。     

Understanding How the Complex Molecular Architecture of Mannan-degrading Hydrolases Contributes to Plant Cell Wall Degradation

Microbial degradation of plant cell walls is a central component of the carbon cycle and is of increasing importance in environmentally significant industries. Plant cell wall-degrading enzymes have a complex molecular architecture consisting of catalytic modules and, frequently, multiple non-catalytic carbohydrate binding modules (CBMs). It is currently unclear whether the specificities of the CBMs or the topology of the catalytic modules are the primary drivers for the specificity of these enzymes against plant cell walls. Here, we have evaluated the relationship between CBM specificity and their capacity to enhance the activity of GH5 and GH26 mannanases and CE2 esterases against intact plant cell walls. The data show that cellulose and mannan binding CBMs have the greatest impact on the removal of mannan from tobacco and Physcomitrella cell walls, respectively. Although the action of the GH5 mannanase was independent of the context of mannan in tobacco cell walls, a significant proportion of the polysaccharide was inaccessible to the GH26 enzyme. The recalcitrant mannan, however, was fully accessible to the GH26 mannanase appended to a cellulose binding CBM. Although CE2 esterases display similar specificities against acetylated substrates in vitro, only CjCE2C was active against acetylated mannan in Physcomitrella. Appending a mannan binding CBM27 to CjCE2C potentiated its activity against Physcomitrella walls, whereas a xylan binding CBM reduced the capacity of esterases to deacetylate xylan in tobacco walls. This work provides insight into the biological significance for the complex array of hydrolytic enzymes expressed by plant cell wall-degrading microorganisms.     

Plant Regeneration from Cell and Protoplast Cultures of Triticum aestivum-Haynaldia villosa Hybrid

Starting materials used in these experiments were taken from Triticum aestivum-Hay-naldia villosa hybrid embryo-derived callus, which had been maintained for nearly two years. To establish suspension cultures, the callus was subcultured till its compact texture became friable, and then shaken in a liquid medium. Upon transferring the suspended cells onto a semisolid medium, high frequency of plant regeneration was achieved.     

植物MADS-box基因研究进展

植物中的MADS-box基因是一个序列特异的调节基因家族,其编码的MADS-box蛋白转录因子以二聚体化的形式通过保守的MADS结构域与特定的DNA序列结合来调控基因的表达,从而调节植物的生长发育.对植物MADS-box基因的分布、分类、结构、功能和前景作了简要的综述。     

Permeabilization of Fungal Hyphae by the Plant Defensin NaD1 Occurs through a Cell Wall-dependent Process

The antifungal activity of the plant defensin NaD1 involves specific interaction with the fungal cell wall, followed by permeabilization of the plasma membrane and entry of NaD1 into the cytoplasm. Prior to this study, the role of membrane permeabilization in the activity of NaD1, as well as the relevance of cell wall binding, had not been investigated. To address this, the permeabilization of Fusarium oxysporum f. sp. vasinfectum hyphae by NaD1 was investigated and compared with that by other antimicrobial peptides, including the cecropin-melittin hybrid peptide CP-29, the bovine peptide BMAP-28, and the human peptide LL-37, which are believed to act largely through membrane disruption. NaD1 appeared to permeabilize cells via a novel mechanism that required the presence of the fungal cell wall. NaD1 and Bac2A, a linear variant of the bovine peptide bactenecin, were able to enter the cytoplasm of treated hyphae, indicating that cell death is accelerated by interaction with intracellular targets.