蚕豆叶片细胞中IAA的胶体金免疫电镜定位

利用胶体金免疫电镜技术对蚕豆(Vicia faba L.)叶片细胞中的IAA定位进行了研究。幼嫩叶片的叶肉细胞中金颗粒主要分布在细胞核和叶绿体中,细胞质及细胞壁也有金颗粒标记。成熟叶片的叶肉细胞中金颗粒主要分布在叶绿体和细胞质,细胞壁也有少量金颗粒标记,液泡中没有发现金颗粒标记。成熟叶片小叶脉的韧皮细胞发现有大量的金颗粒标记,金颗粒主要标记在传递细胞的细胞壁中。小叶脉的维管束鞘细胞中也有很多的金颗粒标记,金颗粒主要分布在叶绿体、细胞质及细胞壁中。幼嫩叶片组织不进行IAA的固定或用正常兔IgG代替IAA抗体染色的对照,很难发现金颗粒标记。对IAA在组织及亚细胞中的定位及其生理意义进行了讨论。     

南瓜属植物离体茎段嫁接维管组织的发育过程

在离体条件下,采用同瓜属植物的下胚轴节段进行嫁接,光镜观察发现：异种嫁接西葫芦／南瓜和南瓜自体嫁接嫁接后６－８ｄ在接穗、砧木的薄壁细胞和嫁接面处愈伤组织细胞中分化出管状分子和筛分子,边接接穗和砧木的质部和韧皮部桥在嫁接后８ｄ形成。随后随发育天数的增加其数目增加,用６（５）ＣＦ作为筛管输导的示踪剂检验了不同发育时期砧木和接穗间的连通情况,发现嫁接后８ｄ从接穗引入的６（５）ＣＦ可以输导到砧木。     

嫁接植株形成过程中接合部组织学和生长素含量的变化

本文应用植物激素间接酶联免疫技术(ELISA),第一次定量检测了嫁接植株形成过程中生长素(IAA)的动态变化。结果表明：嫁接植株发育的前期,亲和性与非亲和性组合其IAA含量的变化相似。在后期,不亲和组合IAA含量急骤减少,而亲和性的组合在第八天即维管束桥分化形成的这一天,可见到IAA高峰值的出现。     

嫁接接合部维管组织分化的激素调节

利用黄瓜（ ＣｕｃｕｍｉｓｓａｔｉｖｕｓＬｉｎｎ．） 试管苗离体茎段自体嫁接系统, 研究ＩＡＡ和ＺＴ对砧木和接穗维管组织分化的影响, 发现外源ＩＡＡ 和ＺＴ 是砧木和接穗间维管束桥分化的必要条件。培养基中外源激素的浓度和种类通过调控维管束桥形成时间和数目以及贯通砧木和接穗的管状分子数来调节嫁接体发育。接合部维管组织分化是生长素和细胞分裂素共同作用的结果。离体茎段自体嫁接系统是一个理想的研究植物维管组织分化的新系统。     

凡纳滨对虾不同组织内SOD、POD酶的细胞化学定位

运用电镜酶细胞化学技术对凡纳滨对虾(Litopenaeus vannamei)体内肝脏、肌肉、心脏、复眼和鳃等5种组织的SOD和POD酶的细胞化学定位进行了研究,并与感染病毒的凡纳滨对虾体内5种组织中SOD和POD的细胞化学定位进行比较。结果显示,在健康对虾体内,SOD酶阳性反应颗粒主要定位于肌肉、心脏、肝脏和鳃等组织细胞的线粒体膜、细胞质中,以及肝细胞的脂滴周围;POD酶主要定位于心脏、鳃和肝脏组织细胞的过氧化物酶体内,肝细胞中脂滴周围也有POD的阳性反应颗粒。感染病毒后,各组织细胞表现出明显的病理性结构变化,大量的髓样小体出现,脂滴数量明显减少。同时各组织中SOD和POD酶的细胞化学定位也发生了明显的变化,表现为心脏、鳃、肌肉组织细胞胞质中的SOD阳性颗粒消失,肝细胞中的SOD阳性颗粒明显减少,在心脏和鳃的线粒体基质内也出现SOD阳性颗粒;POD仍主要定位在过氧化物酶体中,但心脏中的过氧化物酶体解体而有许多呈阳性反应的小颗粒分布在细胞质中。结果表明SOD和POD在凡纳滨对虾防御氧的毒性损伤以及整个机体的免疫功能等方面起着重要的作用。       

木本植物内源生长素免疫胶体金定位分析技术的研究

以木本植物杨树(Populus sp.)和核桃(Juglans regia L.)为材料,对内源生长素免疫胶体金定位技术在固定、烤片、免疫染色、显色等关键环节进行了改进优化与验证.结果显示,优化后适合木本植物定位方法的主要技术要点是:在染色中,通过采用尿素-胰蛋白酶联合消化技术和增加牛血清白蛋白处理大大地改善了抗原修复结果,提高了染色的敏感性和特异性.利用优化后的方法对核桃幼胚和杨树嫩茎诱导生根过程中的吲哚乙酸(IAA)进行定位研究,发现杨树试管嫩茎生根过程中,形成层及周缘维管束有很强的IAA信号,核桃子叶生根中,胚中有很强的IAA信号,胚根中有半圆形、胚芽中有>"形强信号区,胚轴信号较弱,胚根信号最强.研究表明,与传统免疫染色方法相比,优化后的方法对木本植物生长素定位具有敏感性高,特异性强,银颗粒明显,背景清晰,耗时少等特点.     

植物离体茎段嫁接

植物体茎段嫁接系统是在无菌条件下将茎切段嫁接后放入培养基中、使接穗和砧木分别与含不同成分的培养基接触,再署光下培养的一个模拟植物正常生理过程、环境条件可控的实验系统,离体茎段嫁接体的发育与整体类拟,包括接穗与砧木粘连、愈伤组织产生、次生甩间连丝形成和维管束分化等几个步骤,发育进程受植物激素如生长素和细胞分裂素调节。该系统的建立为阐明嫁接体发机理及嫁接亲和性机制提供了重要的依据。     

应用免疫胶体金技术定位感病大麦细胞中的大麦和性花叶病毒

本文报道免疫胶体金标记技术的建立,并用此技术定位大麦叶和根组织超薄切片中大麦和性花叶病毒(BaMMV)。在感染病毒的大麦叶和根细胞中,病毒束、游离病毒颗粒和病毒外壳蛋白多分布于细胞质丰富的细胞中,且以液泡和叶绿体(仅叶组织)周围较多。在细胞器已解体的病根表皮细胞中,有时也可检测到大量游离病毒粒子。少数风轮体或板状集结体上也存在病毒或病毒外壳蛋白。细胞核、叶绿体、线粒体、细胞膜以及其他细胞器上都未见有特异性金颗粒标记。     

犬传染性肝炎病毒在体外细胞质内的发生

通过对犬传染性肝炎病毒（ＩＣＨＶ）在犬肾传代细胞内形态发生及其抗原定位的电镜和免疫胶体金电镜研究,发现ＩＣＨＶ除了在宿主细胞核内发生外,还有一条细胞质内的发生途径。在细胞质内病毒核壳体的装配是以均质致密包涵体和副晶格包涵体为“基地”,这与人们熟知的细胞核内形态发生方式相似。免疫胶体金标记显示,细胞质包涵体中含有大量的ＩＣＨＶ抗原成分,显核壳体在细胞质内装配病毒的结构蛋白来源。此外,在感染的细胞质内还观察到与核内相同的病毒核心样结构。     

蚕豆保卫细胞中钙调素的免疫电镜定位

以蚕豆横切和平切气孔为材料,对钙调素进行了免疫胶体金电镜定位的结果表明:在蚕豆保卫细胞的细胞核、细胞质、细胞膜、叶绿体、液泡、高尔基体、细胞壁中都有金颗粒分布,在线粒体上的分布较少.     

嫁接早期IAA在西葫芦／南瓜嫁接面处薄壁细胞和维管分子中的免疫 …

Immuno-gold localization of IAA in cells of the graft union in the explant internode graft of Cucurbita pepo/Cucurbita moschata were investigated with electron microscopy. In parenchyma cells near the graft union, the gold particles were mainly accumulated in nucleus, plastid and endoplasmic reticulum, while no gold particles was detected in Golgi body, mitochondrion, cell wall and vacuoles. In the differentiating xylem element, the gold particles were labeled in secondary wall and cytoplasm. In the sieve element gold particles were found in the sieve plate, sieve pore and cytoplasm. There was a dense label of the gold particles in the companion cell. The role of IAA in the differentiation of the vascular elements was discussed.     

Location of Caspase 3-like Protease in the Development of Sieve Element and Tracheary Element of Stem in Cucurbita moschata

The casepase is considered to regulate the process of programmed cell death in the development of organisms. In this study, caspase 3-like protease was detected by immunohistochemistry and immunoelectron microscopy during the development of sieve element and tracheary element of stem in Cucurbita moschata Duch. Antibody with brown color (under light microscopy) and gold particles (under transmission electron microscopy) for detecting caspase 3-like protease was mainly displayed in inner phloem, extemal phloem and xylem in the region close to procambium. From the results it was considered that caspase 3-like protease did exist in vascular elements and played different roles during the development of sieve and tracheary elements, and different types of programmed cell death might be carried out. The caspase 3-like protease mainly participated in making cytoplasmic streaming cease and in degrading P-protein bodies; however, it rarely participated in the function for signal transferring in the developmental sieve element. However, it might induce calcium accumulation for rupturing the tonoplast in the signal of PCD in the developmental tracheary element.     

西葫芦的单花粉蛋白电泳

对西葫芦（ＣｕｃｕｒｂｉｔａｐｅｐｏＬ．）的单花粉进行了蛋白电泳分析,结果表明在西葫芦花粉发育的不同阶段,其蛋白电泳图谱存在明显差异,结合细胞学观察结果,对这些差异进行了讨论。同时对同一杂合个体同一雄花相同发育阶段的不同花粉粒的蛋白电泳结果表明,它们之间也存在着差异。     

P PROTEIN IN THE PHLOEM OF CUCURBITA : II. The P Protein of Mature Sieve Elements

During maturation of sieve elements in Cucurbita maxima Duchesne, the P-protein bodies (slime bodies) usually disperse in the tonoplast-free cell. In some sieve elements the P-protein bodies fail to disperse. The occurrence of dispersal or nondispersal of P-protein bodies can be related to the position of the sieve elements in the stem or petiole. In the sieve elements within the vascular bundle the bodies normally disperse; in the extrafascicular sieve elements the bodies often fail to disperse. Extrafascicular sieve elements showing partial dispersal also occur. The appearance of the sieve plate in fixed material is related to the degree of dispersal or nondispersal of the P-protein bodies. In sieve elements in which complete dispersal occurs the sieve plate usually has a substantial deposit of callose, and the sieve-plate pores are filled with P protein. In sieve elements containing nondispersing P-protein bodies the sieve plate bears little or no callose, and its pores usually are essentially "open." The dispersed P-protein components may aggregate into loosely organized "strands," which sometimes extend vertically through the cell and continue through the sieve-plate pores; but they may be oriented otherwise in the cell, even transversely.     

SIEVE-ELEMENT ONTOGENY IN THE ROOT OF EQUISETUM HYEMALE

Roots of Equisetum hyemale L. var. affine (Engelm.) A. A. Eat. were fixed in glutaraldehyde, postfixed in osmium tetroxide, and sieve elements of various ages were examined with the electron microscope. Young sieve elements are distinguished by their position within the vascular cylinder and by the presence of numerous refractive spherules, which originate within dilated portions of the endoplasmic reticulum (ER). Early in development, the sieve-element walls undergo a substantial increase in thickness. This is followed by the appearance of massive ER aggregates in the cytoplasm and then by a phase involving stacking and sequestering of the remaining ER. Nuclear degeneration is initiated shortly after the appearance of the ER aggregates. The chromatin condenses into masses of variable size along the inner surface of the nuclear envelope. The envelope then ruptures and chromatin is released into the cytoplasm. During the period of nuclear degeneration, mitochondria and plastids undergo structural modification, while components such as dictyosomes, microtubules, and ribosomes degenerate and disappear. The remaining cytoplasmic components assume a parietal position in the cell, leaving the lumen of the cell clear in appearance. At maturity, the plasmalemma-lined sieve element contains plastids, mitochondria, some ER, and refractive spherules. At this time many of the refractive spherules are discharged into the region of the wall. Pores between sieve elements occur largely on the end walls. During pore development, tubules of ER apparently traverse the pores, but because of the presence of massive callose deposits in the material examined, the true condition of mature pores could not be determined. The connections between mature sieve elements and pericycle cells are characterized by the presence of massive wall thickenings on the pericycle-cell side. Plasmodesmata in the wall thickening are matched by pores on the sieve-element side. Ontogenetic and cytoplasmic factors argue against use of the term “companion cell” for the vascular parenchyma cells associated with the sieve elements.     

IN VITRO EFFECT OF HORMONES ON THE BARK OF PLUMERIA RUBRA LINN. VAR. ACTUIFOLIA BAILEY

Young bark (with cambium) of Plumeria rubra Linn. var. acutifolia Bailey was cultured in solid media (i) without hormone, (ii) Kinetin (K), (iii) with GA₃ and (iv) with IAA at concentrations of 0.05, 0.10, 0.15 and 0.20 mg per litre. The nutrients of the media were fed laterally through the cambium zone. The amount of the phloem zone was increased considerably by GA₃, less by K and IAA. The lignified secondary wall of the pericyclic living fibres was dissolved by each of the hormones. Sieve tube member length decreased in all treatments, more in higher concentrations. K decreased the frequency of sieve tubes (most at 0.10 mg/α) and increased the frequency of parenchyma cells (optimum at 0.10 mg/α). GA₃ also favoured formation of parenchyma cells and decrease of the frequency of sieve tubes, progressively with the increase of concentration. IAA also increased the parenchyma cell frequency progressively with concentration and decreased slightly the sieve tube frequency. IAA and GA₃ increased ray frequency and decreased parenchyma cell diameter, much at high concentration. But K had less effect on ray frequency and increased parenchyma cell diameter progressively with concentrations.     

STRUCTURE AND DEVELOPMENT OF THE SIEVE ELEMENTS IN PSILOTUM NUDUM

Shoot tissue of Psilotum nudum (L.) Griseb. was fixed in glutaraldehyde and postfixed in osmium tetroxide for electron microscopy. Young sieve elements can be distinguished from contiguous parenchyma cells by their distinctive plastids, the presence of refractive spherules, and the overall dense appearance of their protoplast. The refractive spherules apparently originate in the intracisternal spaces of the endoplasmic reticulum (ER). With increasing age the sieve-element wall undergoes a marked increase in thickness. Concomitantly, a marked increase occurs in the production of dictyosome vesicles, many of which can be seen in varying degrees of fusion with the plasmalemma. Other fibril- and vesicle-containing vacuoles also are found in the cytoplasm. In many instances the delimiting membrane of these vacuoles was continuous with the plasmalemma. Vesicles and fibrillar materials similar to those of the vacuoles were found in the younger portions of the wall. At maturity the plasmalemma-lined sieve element contains a parietal network of ER, plastids, mitochondria, and remnants of nuclei. The protoplasts of contiguous sieve elements are connected by solitary pores on lateral walls and pores aggregated into sieve areas on end walls. All pores are lined by the plasmalemma and filled with numerous ER membranes which arise selectively at developing pore sites, independently of the ER elsewhere in the cell. P-protein and callose are lacking at all stages of development.     

嫁接植株形成过程中接合部组织学和生长素含量的变化

本文应用植物激素间接酶联免疫技术（ＥＬＩＳＡ）,第一次定量检测了嫁接植株形成过程中生长素（ＩＡＡ）的动态变化。结果表明：嫁接植株发育的前期,亲和性与非亲和性组合其ＩＡＡ含量的变化相似。在后期,不亲和组合ＩＡＡ含量急骤减少,而亲和性的组合在第八天即维管束桥分化形成的这一天,可见到ＩＡＡ高峰值的出现。     

Acid invertase is predominantly localized to cell walls of both the practically symplasmically isolated sieve element/companion cell complex and parenchyma cells in developing apple fruits

The acid invertase (β‐fructosidase, EC 3·2·1·26) was localized at subcellular level via immunogold electron microscopy in the phloem‐unloading zone of developing apple fruit. The enzyme (immunogold particles) was found to reside predominantly in the cell walls of the sieve element/companion cell (SE/CC) complex, phloem parenchyma cells and other parenchyma cells. There was almost no gold particle found in cytoplasm and vacuole. This distribution pattern remained unchanged throughout the growing season, but the enzyme numbers varied. The density of immunogold particles increased during fruit development. The immunoblotting of soluble and insoluble acid invertases provided a supporting proof for the assays of immunolocalization. The biochemical analysis showed a predominantly cell‐wall‐distributed activity of acid invertase that corresponds essentially with its amount distribution. The ultrastructural observations showed that there were numerous plasmodesmata between the parenchyma cells, but almost no plasmodesmium between the SE/CC complex and its surrounding parenchyma cells, practically resulting in the symplasmic isolation of the SE/CC complex. It is therefore suggested that the unloading pathway of sucrose from the SE/CC complex may be predominantly apoplasmic in the developing apple fruit, and that the unloaded sucrose may be hydrolysed by the functional acid invertase localized in the cell wall before it is loaded in sink cells.