苜蓿盐适应愈伤组织中蛋白质性质和组分的变化

通过一步筛选获得1.0％NaCl适应愈伤组织。在盐适应愈伤组织中水溶性蛋白和稀碱提取蛋白含量增加,而脂溶性蛋白含量没有明显变化。盐适应愈伤组织水溶性蛋白热稳定性下降;总蛋白抗脱水能力增强。盐适应愈伤组织水溶性蛋白在K~ 存在时,262nm吸收峰增高。盐适应愈伤组织蛋白氨基酸组成发生变化,其中最为明显的是Tyr摩尔百分数增加。Lys摩尔百分数减少。 盐适应愈伤组织中24kD蛋白含量明显增加。应用IEF-,NEPHGE-和native-PAGE-SDS-PAGE三种双向电泳方法同时证明在盐适应愈伤组织蛋白组分与非适应愈伤组织有明显差别。     

盐胁迫下烟草愈伤组织内源活性氧及乙烯的产生与交替途径发生,？…

This paper reported firstly the dynamic changes of the alternative pathway and the cytochrome pathway in tobacco callus under different concentration of salt. The production rate of endogenous ethylene, the contents of active oxygen species (O2-., .OH and H2O2) and the activities of related enzyme (SOD and CAT) were also investigated simultaneously. The results indicated that the actual operation of the alternative pathway (rho Valt) increased gradually and reached the maxima at 0.75% salt concentration, then declined, while the capacity of the alternative pathway (Valt) didn't exhibit the same change pattern with rho Valt and the cytochrome pathway (rho' Vcyt) changed contrary to rho Valt. At the same time, H2O2 and O2-. accumulated rapidly and reached their peak value at about 0.5% and 0.75% salt concentration respectively, while the content of .OH increased consistently. The production rate of endogenous ethylene increased rapidly and reached its maxima at about 0.5% salt concentration. These data demonstrated that changes of Valt in tobacco callus were associated with a parallel production of H2O2 and endogenous ethylene and a opposite production of .OH, while rho Valt changed parally with the production of O2-.. On the basis of above results, it was deduced that the changes of the development and operation of the alternative pathway in tobacco callus under salt stress might be correlated with the production of endogenous ethylene and the active oxygen species. The possible participation of the alternative pathway in response to salt stress was also discussed.     

烟草愈伤组织在热胁迫过程中活性氧与抗氰呼吸变化的关系

烟草愈伤组织在０－１４ｈ高温（４０℃）胁迫期间,其体内的Ｏ＾－２和Ｈ２Ｏ２迅速积累,分别在２和６ｈ左右达到极大值。同时清除它们的酶ＳＯＤ和ＣＡＴ活性迅速上升,极大值的分布位置分别为２和１０ｈ左右,而腔摁期间的抗氧呼吸比未胁迫（０ｈ）时显著地下降,但在胁迫期间抗氰呼吸于６ｈ左右出现一峰值;用外源Ｈ２Ｏ２和Ｏ２及清除它们的酶的抑制剂ＡＴ和ＤＣＣ分别处理愈伤组织,发现抗氧呼吸明显地加强,推测交替氧化酶可     

苜蓿愈伤组织中的盐胁迫蛋白

0.5％NaCl抑制愈伤组织生长,处理后期(第21天和28天检测)24kD蛋白含量明显增加。1.0％,2.0％和3.0％NaCl处理的愈伤组织不生长,未检出24kD蛋白增加,但36～42kD蛋白大量增加,并且有随处理的盐浓度增高而增加的趋势。 在1.0％NaCl适应愈伤组织(简称S-1)中24kD蛋白含量明显增加,而36～42 kD蛋白含量下降到对照水平。~(35)S-Met体内标记表明,增加的24kD蛋白是新合成的。S-1回到无盐5代后,仍保持提高的耐盐性和24kD蛋白含量。24kD蛋白含量的增加不受甘露醇胁迫的诱导。初步离心分离的细胞亚组分表明,24kD蛋白主要位于胞质和细胞器膜。在烟草S-1细胞中也发现24kD蛋白含量增加。     

烟草愈伤组织在热胁迫过程中活性氧与抗氰呼吸变化的关系

烟草愈伤组织在 0～ 14h高温 (4 0℃ )胁迫期间 ,其体内的O- ·2 和H2 O2 迅速积累 ,分别在 2和 6h左右达到极大值。同时清除它们的酶SOD和CAT活性迅速上升 ,极大值的分布位置分别为 2和 10h左右 ,而胁迫期间的抗氰呼吸比未胁迫 (0h)时显著地下降 ,但在胁迫期间抗氰呼吸于 6h左右出现一峰值 ;用外源H2 O2 和O- ·2 及清除它们的酶的抑制剂AT和DCC分别处理愈伤组织 ,发现抗氰呼吸明显地加强。推测交替氧化酶可能同抗氧化酶如SOD和CAT一样参与了活性氧的清除 ,提出活性氧含量的变化可能是导致热胁迫过程中抗氰呼吸变化的主要原因之一。     

烟草愈伤组织生长和衰老过程中多聚核糖体类群的变化(英文)

本研究中测定了黄花烟草(Nicotiana rusticaL cv.Gansu yellow flower)愈伤组织生长和由碳水化合物亏缺引起的衰老过程中多聚核糖体类群和蛋白质含量的变化,以期查明衰老的烟草愈伤组织中蛋白质合成速率与蛋白质含量变化的相关性。 继代培养的烟草愈伤组织经过约5d的生长迟滞期,进入指数生长期,第20天后生长停止,干重缓慢下降;第25天出现类似果实成熟时的呼吸跃变现象,呼吸商(RQ)开始下降,呼吸底物由糖转向游离氨基酸,表明在本实验条件下,烟草愈伤组织在培养20～25d后由生长转向衰老,这时蛋白质含量(占细胞总蛋白的90％～95％)立即降低,第35天降低了26％。代表蛋白质合成能力的多聚核糖体相对含量和总核糖体的相对含量在培养20d后开始减少;两者的比值也降低,这与植物衰老过程中蛋白质含量的降低基本一致,表明烟草愈伤组织衰老过程中蛋白质含量的降低.与蛋白质合成能力的下降可能有一定的关系。由于多聚核糖体的解聚并不伴随有单核糖体的增加,也暗示衰老过程中单核糖体被迅速破坏。     

烟草愈伤组织生长和衰老期间呼吸代谢的改变

前人(Ross和Thorpe 1973,Thorpe和Laishley 1973,Brown和Thorpe 1982)曾报道了烟草愈伤组织芽形成期间呼吸速率、线粒体活性、底物代谢途径和有关呼吸酶活性的变化。我们对烟草愈伤组织呼吸代谢的研究证明:组织分化和芽原基的形成与HMP途径运行升高相联系(毕玉蓉和梁厚果1987);愈伤组织的呼吸链存     

5,6-二氯-吲哚乙酸对烟草愈伤组织衰老的延缓作用

5,6-二氯-吲哚乙酸对革新烟草愈伤组织生长有影响。当愈伤组织在MS_0(对照)和MS 2,4-D培养基上培养22d时,生长停滞,细胞已呈空泡状,正常的超微结构完全破坏,细胞器不复存在,愈伤组织明显褐化。但在MS 5,6-Gl_2-IAA培养基上的愈伤组织仍能正常生长,鲜重和干重下降亦明显延缓,细胞含有原生质内含物,各种细胞器的超微结构仍保持正常。此外,后者的SOD同工酶也明显不同于其它培养基上的愈伤组织,暗示5,6-Gl_2-IAA对烟草愈伤组织衰老的延缓作用可能与SOD同工酶的调节作用有关。     

A Comparative Study on Protein Metabolism During Subculture and Differentiation of Tobacco Callus

Comparative study on the subcultured callus of tobacco (Nicotiana tabacum L. cv. Willow leaf) has revealed that protein contents and pr otease activities slowly decreased in the callus during differentiation and bud formation. The synthetic rates of fraction Ⅱ protein (water soluble protein and enzymes) and ribosomal hist one, the levels of total ribosomes, especially the levels of polyribosomes which function the protein synthesis, were higher in the differentiating callus than those in the subcultured callus. This indicates that protein synthesis in differentiating callus is greater than that in non-differentiating callus, and that the protein pattern synthesized in differentiating callus may differ from that in non-differentiating callus. During the late period of culture, the protease activities in subcultured callus rapidly increased, and the levels of polyribosomes, protein synthetic rates and protein contents apparently declined, which may be the result of metabolic changes in callus senescence. Meanwhile in the differentiating callus the protein contents, protein synthesis rates and polyribosome levels although somewhat declined accempanying the growth of formed bud, were still much higher than those in the subcultured callus.     

硝酸银对离体培养烟草叶片愈伤组织形成和芽再生及其脯氨酸和丙二醛含量的影响(简报)

培养基中添加不同浓度硝酸银离体培养烟草叶片的结果表明,1～5mg·L-1硝酸银可提高烟草愈伤组织的芽分化率,5 mg·L-1硝酸银对芽再生的促进作用最佳,而高于10mg·L-1的硝酸银抑制愈伤组织的形成和芽再生.在愈伤组织和再生芽中,脯氨酸和丙二醛含量均随硝酸银浓度的增加而增加.     

Microtubular Organization in Tobacco Cells: Heat-Shock Protein 90 can Bind to Tubulin in Vitro

Abstract: The heat-shock protein 90 (HSP90) from tobacco VBIO cells specifically binds to nitrocellulose that had been coated with polymerized microtubules or tubulin dimers. HSP90 is expressed preferentially during cell division and becomes down-regulated during cell elongation. HSP90 cofractionates with tubulin dimers during affinity chromatography with sepharose coupled to the tubulin-binding drug ethyl N-phenylcarbamate (EPC). Binding of HSP90 to EPC-sepharose depends on the presence of tubulin. Antibodies against tubulin and HSP90 immunoadsorb HSP90 and tubulin, respectively. These results demonstrate that HSP90 behaves as a microtubule-binding protein in vitro.     

细胞外钙调素对烟草悬浮培养细胞蛋白质磷酸化作用的影响

用液体闪烁计数法研究了细胞外钙调素对烟草悬浮培养细胞质蛋白质磷酸化的作用。结果表明烟草细胞细胞质蛋白质磷酸化活性在细胞培养过程中逐渐增加,达到最高峰后又开始下降。在细胞质蛋白质磷酸化强度高峰时,加入抗CaM血清后,细胞质蛋白质磷酸化活性受到了部分抑制。加抗CaM血清后再补加CaM能够部分解除抗CaM血清对细胞质部分与细胞核部分蛋白质磷酸化的抑制作用。外加纯化钙调素可以引起烟草悬浮培养细胞细胞质蛋白质磷酸化的活性增强,并且这种增强作用具有时间（高峰为70min）与剂量（最适为CaM10-7mmol/L）依赖性。CaM引起的细胞质蛋白质磷酸化变化与红光所引起的细胞质蛋白质磷酸化变化在时间进程上是不相同的。     

在继代培养中玉米花粉愈伤组织无性系的核酸和蛋白质变化

本实验室筛选出具有不同分化能力的单倍体玉米无性系组织,挑选其大小相同、新鲜的、具有分化能力的无性系No.1和完全丧失分化能力的无性系No.250组织,转接到分化和继代两种培养基上,分析其DNA和RNA以及蛋白质含量的差异,以了解组织在分化过程中DNA、RNA和蛋白质动态。试验结果表明,在分化和继代两种培养基上,No.1的DNA、RNA和蛋白质含量都高于No.250;No.1和No.250在分化培养基上DNA和RNA含量增加的速度比在继代培养基上要快;在组织分化过程中,No.1会出现一些新的小分子量蛋白质分子,而No.250中却没有,这些特殊的蛋白质分子可能与组织分化有关。