毛竹茎秆纤维发育过程中Ca2+分布的时空变化

利用焦锑酸盐沉淀技术，对毛竹茎秆纤维发育过程中Ca^2＋的时空变化进行了研究。在纤维原始细胞发育期．Ca^2＋主要分布在细胞壁和细胞核染色质中；随着初生壁的形成，大量的Ca^2＋在液泡膜内侧成稀疏点状分布，在吞噬泡和降解的细胞质中出现Ca^2＋反应颗粒的沉积，液泡内逐渐出现大量的絮状Ca^2＋沉积，在细胞核和细胞壁上没有Ca^2＋分布；随后细胞质中Ca^2＋大量聚集，少量Ca^2＋沿液泡膜内侧分布，而液泡中Ca^2＋含量变得极少，在细胞壁、胞间连丝和细胞核中几乎没有Ca^2＋分布；随着次生壁的形成，胞质内的Ca^2＋浓度增加，并随着次生壁的逐渐加厚而聚集成块状；在次生壁形成的整个过程中，在降解的细胞质、凝聚的染色质、纹孔和运输小泡膜上一直存在Ca^2＋。结果表明：Ca^2＋参与了毛竹茎秆纤维细胞的增殖过程和细胞壁的整个形成过程；胞质Ca^2＋的内流是引起纤维细胞PCD的重要原因之一，并参与了PCD过程中原生质体的降解。     

干旱逆境下小麦幼苗细胞叶绿体内钙离子浓度变化的电镜细胞化学研究

采用改进的焦锑酸钙沉淀的细胞化学方法，探讨了在干旱逆境条件下叶绿体与Ca^2 水平变化的关系。结果表明：在正常水分下生长的小麦幼苗，其叶绿体中含有少量Ca^2 ；水分胁迫24、48h，叶绿体膜上密布Ca^2 ；随着胁迫时间的增加，叶绿体超微结构受到的伤害越发严重，最后解体。     

毛竹茎秆纤维发育过程中Ca~(2+)-ATPase分布的动态变化

采用超微细胞化学定位方法,对毛竹茎秆纤维发育过程中Ca2 -ATPase分布的动态变化进行了研究.在原始细胞形成期,Ca2 -ATPase活性产物主要分布在质膜、核染色体、染色质及核仁上.在初生壁形成早期,质膜上Ca2 -ATPase活性增强;随着纤维细胞的逐渐液泡化,液泡膜、细胞质、质膜内陷和同心圆潴泡上逐渐出现Ca2 -ATPase活性产物的分布;在初生壁形成后期,液泡膜上的Ca2 -ATPase活性增强,在运输小泡上出现Ca2 -ATPase活性产物分布,质膜、细胞质、染色质和核仁上始终具有较强的Ca2 -ATPase活性.随着次生壁的形成,纤维细胞发生程序性死亡(PCD),在质膜、胞间连丝和降解的液泡膜、细胞质、核染色质上具有较强Ca2 -ATPase活性;随着次生壁的逐渐增厚,大量具有Ca2 -ATPase活性的运输小泡在前四年中持续存在,以后逐渐减少;而在六年生茎秆纤维细胞的质膜、胞间连丝、凝聚的核染色质和降解的原生质体中始终具有Ca2 -ATPase活性.结果表明,ca2 -ATPase参与了毛竹茎秆纤维细胞的增殖过程、细胞壁形成过程及PCD过程中原生质体的降解.     

不同粒型小麦品种胚乳淀粉体的扫描电镜观察

对3个不同粒型小麦品种胚乳淀粉体的大小，形状、分布和发育等特性进行了扫描电镜观察。结果表明，3个品种胚乳细胞淀粉体均为单粒淀粉，可根据淀粉体的大小分为三种类型：Ⅰ、Ⅱ，Ⅲ，型。Ⅰ型为椭球形，大粒淀粉；Ⅱ型为椭球形或橄榄球型，中粒淀粉；Ⅲ型为近圆球形，小粒粉，鄂恩1号Ⅱ型淀粉体多为橄榄球型，明显异于其它品种。各品种颖果腹部Ⅰ、Ⅱ型淀粉体多，排列紧密，背部Ⅲ型淀粉体较多，中间胚乳细胞淀粉体以Ⅰ、Ⅲ型为主，排列疏松。颖果腹部淀粉的发育和排列明显优于背部和中间，小粒型品种胚乳细胞淀粉体育好，淀粉充实度高；大粒型品种相反，淀粉体排列疏松，发育差，大粒淀粉体通过网状膜与中小淀粉体相连。     

植物细胞G6P酶活性的电镜细胞化学定位方法

对动物细胞Ｇ６Ｐ酶的电镜细胞化学方法稍加改进，将其应用于植物细胞中得到了良好效果。Ｇ６Ｐ酶活性在细胞核、细胞膜、液泡膜、内质网及解体细胞中小泡膜上均有显示。     

冬季沙冬青液泡中膜状内含物的超微结构研究

冬季沙冬青叶肉细胞中由于液泡膜内吞现象极其普遍，以致常常形成各种细胞质突起，并有丰富的颗粒状和纤维状物质及大量的膜状结构存在于液泡中。膜状结构大小不等，形态各异，膜层排列也不一样。有的相当紊乱，有的比较规则，有的甚至呈同心圆形。同心圆的内部膜层时而清楚，时而模糊，时而是一团电子密度很高的物质。在这些液泡中常有一种电子密度很高，近似圆形的内含物，它的表层中偶尔有膜状结构。冬季沙冬青液泡膜的大量内吞可能与沙冬青具有高度的抗寒性有关。     

沙冬青叶肉细胞中液泡膜内陷特征的电镜观察

沙冬青(Ammopiptanthus mongolicus)是我国温带荒漠地区特有的常绿灌木,是国家重点保护的植物。它既能防风固沙,又能结瘤固氮,又可入药。对于沙冬青的生理生态和解剖学特征已有报道,但对其叶肉细胞中液泡膜内陷特征尚未见到报道。根据我们的研究观察,发现沙冬青叶肉细胞液泡膜的内陷特征主要表现在如下两个方面:一、液泡膜首先向内膨起,形成小泡,由小到大,并反复折叠,形成大的膜状结构。这种膜状结构彼此差异很大,有的只有一层膜,其膜所包围的空间中很少有可见成分,有的体积较大,形状复杂,膜层之间有一些泡状或     

水稻胚乳发育中线粒体定向淀粉质体转变及琥珀酸脱氢酶的研究

以水稻胜泰一号为材料，对其开花后发育前期颖果进行了超微结构观察，查明在某一特定时期线粒体大量转变为淀粉质体。进而对线粒体标志酶-琥珀酸脱氢酶进行了电镜细胞化学定位分析，在胚乳细胞中线粒体的内膜和嵴上均有显著的酶活性，进一步证实胚乳细胞中线粒体转变成淀粉质体的事实。     

大豆在发芽初期子叶细胞液泡的形成

胞器是细胞内部结构和功能上的基本单元,也是细胞生物学家研究的主题,在胞器的研究中,液泡是比较少受重视的一种。近来在对液泡的了解上除了传统渗透压的调节、营养与盐类的储存之外,也有新的文献报告可能是二级信息的储存场所(1)。我们在研究大豆(Glycinemax L.)发芽过程的研究上,观察到大豆在发芽初期,子叶之上皮细胞和叶肉细胞的液泡,是由蛋白质体水解后形成的。     

文昌鱼精子发生过程中高尔基体和线粒体的演变规律电镜观察

本文应用电镜超薄切片和冷冻蚀剂技术,研究厦门文昌鱼(Branchiostoma belcheri Gray)精子发生过程高尔基体和线粒体的演变规律。在文昌鱼精子发生过程中,高尔基体发生一系列的演变和转化过程。生精细胞发育分化为精母细胞,高尔基液泡数量明显增多,大部份集中在高尔基区及其附近。当冷冻劈裂这些高尔基液泡时,显示膜囊的两个断面,即内叶外面(PF面)和外叶内面(EF面),两面上的膜蛋白颗粒的分布和数量有着明显差异,前者分布均匀,颗粒密集,后者则较稀少。精细胞时期,高尔基液泡颇为发达。在精细胞变态早期阶段,     

水稻胚乳发育中线粒体向淀粉质体转变及琥珀酸脱氢酶的定位

以水稻胜泰一号为材料 ,对其开花后发育前期颖果进行了超微结构观察 ,查明在某一特定时期线粒体大量转变为淀粉质体。进而对线粒体标志酶———琥珀酸脱氢酶进行了电镜细胞化学定位分析 ,在胚乳细胞中线粒体的内膜和嵴上均有显著的酶活性 ,进一步证实胚乳细胞中线粒体转变成淀粉质体的事实     

‘麦香’桃叶片变色期色素含量及超微结构的变化

本文以桃的栽培品种‘麦香’（Prunus persica‘mai xiang’）为试材,在8月中旬其叶片由绿变紫红时,对其不同叶位的叶片色素含量进行了测定;以叶色维持绿色不变的品种‘照手姬’桃（Prunus persica‘terutehime’）为对照,并观察了这2个品种的叶片细胞超微结构。结果表明：当花色苷与总叶绿素、类胡萝卜含量的比值约为1∶3.86∶0.43时叶片开始转为淡紫色;当三者含量的比值达到1∶1.70∶0.18时,‘麦香’的整个叶片转变为紫色;当三者的比值大于1∶1.35∶0.16时,叶片的紫色加深变为紫红色。超微结构研究发现,‘麦香’的顶端嫩叶与‘照手姬’的存在显著差异,‘照手姬’桃叶绿体基粒片层清晰,而此时‘麦香’叶绿体基粒片层已表现出明显的松散,线粒体膜有降解现象,而且在上表皮细胞和栅栏组织的液泡中已存在不明物质,这种幼龄期表现的衰老迹象,可能是‘麦香’桃的早熟性决定的。在基部叶片的超微结构中,两品种都出现了相似的衰老现象,即叶绿体片层结构严重扭曲并出现解体现象、嗜锇颗粒增多变大、线粒体外膜解体,内嵴混乱。此外’麦香’叶片中还显示出特有的结构：栅栏组织细胞的液泡和上表皮细胞出现大量絮状或粒状的黑色物质。本实验结果表明,‘麦香’桃叶片的成色取决于花色苷和总叶绿素的比例,‘麦香’桃在变色期合成花色苷,然后可能运输到栅栏组织的液泡和上表皮细胞,使叶片呈现紫红色。     

Effect of N-nitrosodiethylamine on the liver cells of chick embryos in primary culture

The morphology and proliferative activity of liver cells from chick embryos were studied. In vitro, the cells were treated with N-nitrosodiethylamine (NDEA) in doses of 100 and 75 mg/ml of culture medium for a 10-day period. The primary culture from liver cells of 9-day chick embryos was prepared on the highly permeable celloidine membrane. In early periods of cultivation there were degenerative signs, mainly in the parenchymal cells, which shows a cytotoxic effect of NDEA. Proliferation of a small population of light epithelioid cells was observed towards the end of the experiment. There were also some atypical and pathological mitoses in the fibroblasts. The obtained results show that a neoplastic transformation of the chick embryonal liver cells occurs under in vitro conditions.     

水稻胚乳细胞淀粉质体被膜与其增殖的关系

水稻胚乳细胞经高锰酸钾固定法固定后，显示出十分清晰的内膜结构，尤其展现了淀粉质体被膜与淀粉质体增殖在结构上的密切关系。常见的淀粉质体出芽、缢缩和形成中间隔板的增殖方式分别与淀粉质体外层被膜、内外层被膜、内层被膜的活动有关。另外，淀粉质体外层被膜也能出芽，形成双层膜小泡，再积累淀粉形成淀粉质体；而淀粉质体内层被膜向内出泡或内外层被膜同时内陷，在淀粉体内形成新淀粉质体，这是淀粉质体增殖的两种新方式。对淀粉质体被膜在淀粉质体增殖中的作用进行了讨论。     

Kmu and K-Band Irradiation of Giant Algal Cells: The Absence of Detected Bioeffects at 100 W/m2

Single cells of characean algae were exposed at 100 W/m2, and for periods of 100 ms to 1 h, to CW microwave radiation at 17 discrete frequencies over the range 12.4-26.5 GHz. In an attempt to detect resonances or other interactions between this radiation and membrane ion transport processes of the cells, the vacuolar potentials of the cells were monitored before, during, and after exposure and analyzed for radiation-correlated shifts. No unequivocal evidence of such interactions was observed, despite the fact that the most sensitive measurements were capable of resolving shifts of one part in 10 000.     

Low-power 2.45-GHz microwave radiation affects neither the vacuolar potential nor the low frequency excess noise in single cells of characean algae

Single, giant cells of the eukaryotic green algae Chara braunii and Nitella flexilis were subjected to short-, intermediate-, and long-term irradiations with 2.45-GHz microwaves. A search was carried out for radiation-correlated shifts (i) in both the dc level and the rms low-frequency excess noise of the vacuolar potential and (ii) in the membrane resistivity. No reliable shifts were observed, either in normal cells or in cells subjected to reduced temperatures or the poison ethacrynic acid.     

Cytochemical and electron probe X-ray microanalysis studies on the distribution change of intracellular calcium in columella cells of soybean roots under simulated microgravity

The columella cells of soybean roots grown under gravity and simulated microgravity induced by a clinostat were examined using potassium pyroantimonate (PA) and quantitative X-ray microanalysis of cryosections to determine the role of Ca in the regulation of the gravitropic response. Amyloplasts in the columella cells were localized exclusively at the bottom under gravity, but diffusely distributed in the cytoplasmic matrix under simulated microgravity, thus supporting the statolith theory. In the columella cells, PA precipitates containing Ca were diffusely distributed in the cytoplasmic matrix under gravity. Under simulated microgravity, however, they decreased in number and size in the cytoplasmic matrix, whereas increased only in number in the vacuole, indicating that Ca moved from the cytoplasmic matrix into the vacuole. The vacuole of columella cells contained mostly electron-dense granular structures localized along the inner surface of tonoplasts, which closely resembled the tannin vacuole reported in Mimosa pulvinar motor cells. Under simulated microgravity, their configuration changed dramatically from a granular shape to a flat plate. The quantitative X-ray microanalysis of cryosections showed that the vacuolar electron-dense structures contained a large amount of Ca. Under simulated microgravity, the concentration of Ca increased conspicuously in these vacuolar electron-dense structures, concomitantly with a marked decrease of K in the vacuoles and an increase of K in the cell walls. These results suggest that the release of Ca(2+) from, and uptake by, the vacuolar electron-dense structures is closely related to the signal transmission in the gravitropic response and that Ca movement occurs opposite to that of K.     

An osmium-ferricyanide staining method for the intercellular space in the small intestinal epithelium.

The post-fixation with osmium tetroxide and potassium ferricyanide (OsFeCN) produced dense deposits on the outer surface of the lateral plasma membrane in the mouse small intestinal epithelium. The deposits also filled up the intercellular space. No deposits were found on the surface of apical and basal plasma membranes. This staining pattern was highly reproducible when pH of the OsFeCN solution was adjusted to 7.0 by cacodylate buffer without calcium ion. Thus, our modified OsFeCN method is useful to selectively stain the intercellular space in epithelial tissues.     

Periciliary structure of developing rat photoreceptor cells. A deep etch replica and freeze substitution study

The purpose of this study is to identify the morphological machinery for selective transport of proteins required in the outer segments of the rat photoreceptor cell. As a first step, the three-dimensional architecture of the periciliary region and its developmental changes were examined. Freeze-deep-etching and freeze-substitution methods combined with rapid freezing technique were used. The apical surface of the inner segment was swollen and partially enclosed the base of the connecting cilium in early postnatal stages, so that the basal region of the connecting cilium was inevitably surrounded by a groove. However, a specialized periciliary ridge complex as seen in frog photoreceptor cells has never been observed in rat photoreceptor cells. The cytoplasmic surface of the plasma membrane of the apical inner segment in the vicinity of the connecting cilium was covered with loose fine filaments. However, it was unlikely to be a possible structural candidate for selective transport of membrane proteins. This study also revealed the interior structure of the connecting cilium. Actin filaments in the distal axonem formed a complicated meshwork together with an unknown substance. Since S1 decorated filaments were not detected in the middle region of the connecting cilium, actin filaments at the base of outer segment seem to be independently polymerized locally from G-actin that is transported from the inner segment.