冬季沙冬青叶肉细胞液泡中泡状内含物的研究

用透射电镜观察了沙冬青叶肉细胞液泡中泡状内含物的形成。在早期,这种泡状内含物位于细胞质中,它由大小不等、形态各异的小泡组成,后经液泡膜内吞进入液泡。液泡中的泡状内含物主要位于两个正常叶绿体之间,附近的细胞质较多,内有丰富的内质网、高尔基体、质膜管状突起和由它们产生的小泡。也有一些液泡泡状内含物出现在解体叶绿体附近。前者主要来自内质网、高尔基体和质膜,后者则主要起源于解体的叶绿体。这种泡状内含物的形成可能与增强植物的抗冻性有关。     

箭舌豌豆根瘤细胞液泡中一种特殊内含物的研究

用透射电镜观察了箭舌豌豆根瘤侵染细胞。结果表明,有一些小泡出现在细胞质膜和侵入线附近,它们不断向中央液泡运动,并在运动中相互靠近形成小泡团。当其到达中央液泡时,附近的液泡膜产生内吞,形成突起。最后,这些突起脱离液泡膜,在中央液泡中形成一种由管状结构和小泡组成、表面具有一层被膜的特殊内含物。本文还讨论了此种内含物的起源及其与根瘤抗旱和细菌周膜扩增的关系。     

红豆草根瘤侵染细胞中液泡内含物的超微结构特征

用透射电镜研究了红豆草（Onobrychis viciifolia）根瘤侵染细胞中液泡内含物的超微结构特征。结果表明,早期发育侵染细胞的液泡中只含有少量的纤维状物质。随着细胞的发育,液泡不断变大,液泡中的纤维状物质和膜状物质越来越多。在中央液泡形成后,液泡中的纤维状物质逐渐减少,类细胞质、泡状和膜状物质明显增多,它们常由一层来自液泡膜的膜包围,其形状一般近似圆形或椭圆形。液泡内含物的大量出现可能与红豆草及其根瘤具有高度的抗旱件有关。     

冬季沙冬青细胞质中一种高电子密度结构的电镜观察

用透射电子显微镜观察了冬季沙冬青的叶肉细胞。观察表明,其细胞质中有一种电子密度很高的结构,分布广,主要位于有一定解体现象并含有较多嗜锇小球叶绿体附近,有的甚至与叶绿体被膜贴在一起,很少存在于发育良好的叶绿体附近和液泡中。其大小不同,通常为椭圆形,有时也近似圆形。表面没有包围膜,泡状结构少,常有突起。这种结构的电子密度很高,染色较均匀,冬季大量出现可能与提高植物的抗寒性有关.     

大豆根瘤侵染细胞中一种细胞质内含物的电镜观察

在中国丰收11号大豆根瘤侵染细胞中,我们发现了一种电子密度很高,体积很大,形状为圆形或近似圆形,外面没有界膜,常位于胞间隙附近的特殊的细胞质内含物。高尔基体及其小泡,丰富的粗糙型内质网和核糖体常在它的附近,其中一些核糖体正沉积在它的表面。它主要是由核糖体凝聚而成,高尔基体和内质网在它的形成中也起了一定作用。它的内部含有颗粒状,纤维状,泡状和管状物质。它的出现似乎与侵染细胞固氮有关。     

鱼腥藻7120细胞液泡内含物的初步测定

对鱼腥藻7120细胞液泡内含物中4种水溶性的物质进行了测定,液泡中4种物质占整个细胞中4种物质的比例分别为：蛋白质：14．1％;还原糖：34．4％;核酸：28．5％;藻青蛋白12．1％。     

侵染细胞中一种内含物的组化研究

在大豆根瘤中有一种非常特殊的细胞质内含物，只存在于侵染细胞中，一个细胞通常只有一个，一般位于细胞的外周部分，常常靠近胞间隙。这种内含物通常为圆形，其直径在１－２μｍ之间，主要由颗粒状物质，管状和泡状成分组成。它经甲苯胺蓝Ｏ染色后呈深蓝色，苏丹黑Ｂ染色后呈深黑色，考马斯蓝染色后呈蓝色，因此它不是类聚核糖核蛋白体，也不是一般的蛋白体和脂滴或脂质体，而可能是一种蛋白质和脂的复合物。其作用可能与共生固氮中     

甜菊愈伤组织分生区细胞中膜内含物的超微结构研究

生长在分化培养基上的甜菊（Ｓｔｅｖｉａ ｒｅｂａｕｄｉａｎａ）愈伤组织分生区细胞中存在双膜和多膜内含物。电镜观察表明,这些膜内含物是由一圈或多圈呈同民贺或卷绕状排列的内质网包围部分细胞质而形成的。双膜内含物内外层膜的靠细胞质表面有核糖体附着,而多膜内含物仅在其最外层潴泡的外膜上偶有和量核糖体附着。附着细胞液泡化程度的提高,多膜内含物通过液泡膜内陷而转移到液泡中或通过消化其中被包围的细胞质及内膜而转     

箭舌豌豆根瘤液泡中细菌周膜来源的研究

电镜观察结果表明,幼龄箭舌豌豆根瘤侵染细胞的细胞质较少,中央是一些体积较大的液泡。细胞质中侵入线经常可见,由侵入线释放出来的细菌均有细菌周膜。这些细菌只位于细胞质中,不出现在液泡里面。成熟根瘤中的侵染细胞与此不同,它们中有大量的成熟侵染细胞,细胞质丰富,里面充满大量细菌,中央常有一个大液泡。当中央液泡发育到一定程度时,位于其附近的细菌可通过液泡膜内吞、液泡膜与细菌周膜融合及液泡膜破裂3种途径进入液泡,后一种途径常伴有寄主细胞质。液泡中的细菌绝大部分裸露在外,只有个别细菌具有细菌周膜且多位于液泡膜的破损处附近,因此细菌周膜可能是原来就有的。     

甜菊愈伤组织细胞中的液泡膜内突和液泡内囊泡

对生长在分化培养基上的甜菊愈伤组织分生区细胞的液泡膜内突和液泡内囊泡,进行了超微结构和酸性磷酸酶细胞化学研究。在不同液泡化时期的细胞中,都存在不同大小和形态的液泡膜内突,它们有的缺乏明显的内含物;有的含有许多小泡或复杂膜系;有的含有一个较大的具许多小泡或复杂膜系的膜束缚囊泡。在液泡内还存在一些游离的液泡内囊泡,它们通常具有两层紧贴的界膜或为多层同心膜,推测它们来自液泡膜内突。ＡｃＰａｓｅ定位结果显     

Development of Specific Inclusion in the Mesophyll Cells of Ammopiptanthus mongolicus

The development of specific inclusion in the mesophyll cells of Ammopiptanthus mongolicus was observed by means of transmission electron microscopy. The inclusion is approximately oval-shaped with very high electron-density. It originates from outside of the central vacuole. During its early development it only contains small amount of vesicle-like elements and electron-dense materials. Then the two kinds of components gradually increase in amount and form a protuberance by endocytosis of the tonoplast. The protuberance becomes larger and larger, sometimes even occupies a great part of the vacuole. Later, the vesiclelike elements gradually decrease as the electron-dense materials rapidly increase, eventually filling up the protuberance. The protuberance gradually contracts and finally detaches from the tonoplast and immerses freely in the central vacuole. However, such inclusions were never found in small vacuoles. The inclusions usually appear in cold season and contain large quantity of lipid.     

ULTRASTRUCTURAL STUDIES OF PINUS PINASTER NEEDLES: THE ENDODERMIS

The endodermis in the needles of Pinus pinaster was examined with light and electron microscopy. The endodermis is composed of very long, radially flattened cells, filled with a large central vacuole, which contains spherical dense bodies whose concentration decreases from the ends of the cell to the middle part. They are individually surrounded by a fine granular matrix. The central vacuole is bounded by a thick tonoplast. Other small, clear vacuoles are limited by a thin tonoplast. The parietal cytoplasm contains relatively few ribosomes, long slender chloroplasts, and lipid bodies. The smooth endoplasmic reticulum is highly developed along the tangential walls and frequently connected, or apposed, to the plasma membrane. Numerous primary pit fields are seen in the radial walls which are lignified and in the tangential walls; the latter exhibit a characteristic loosening of the outer layer of the wall. The lipid bodies are connected to endoplasmic reticulum tubules. The role of the endodermis in the active transport of water inside the needle is discussed in reference to previous physiological studies. The chemical composition of the vacuolar dense bodies is as yet unknown.     

THE DEVELOPMENT OF MUCILAGINOUS RAPHIDE CRYSTAL IDIOBLASTS IN YOUNG LEAVES OF TYPHA ANGUSTIFOLIA L. (TYPHACEAE)

Raphide crystal idioblast initiation occurs in the uppermost region of intercalary meristems in young leaves of Typha angustifolia L., and development proceeds acropetally. Idioblast differentiation commences with a loss of stored lipids, depletion of starch from amyloplasts, enlargement of the nucleus and nucleolus, cell elongation, and the formation of a central vacuole. Crystalloplastids are formed via dedifferentiation of amyloplasts, followed by an increase in plastid number as cell volume increases with cell elongation. Crystalloplastid membranes stain intensely with periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP). Following crystal production within the central vacuole, crystalloplastids differentiate lobed regions, dense with plastid ribosomes, thylakoids, lamellae, and plastoglobuli. Mucilage, which stains with PA-TCH-SP, appears to be formed at the tonoplast in the central vacuole and follows differentiation of crystalloplastid lobes. Crystal chambers are surrounded by lamellae during mucilage accumulation and the crystals undergo a change in shape. Lobed crystalloplastids may be involved in vacuolar mucilage formation in these types of raphide crystal idioblasts.     

Tonoplast and Soluble Vacuolar Proteins Are Targeted by Different Mechanisms

The delivery of proteins to the vacuole and its limiting membrane (the tonoplast) by the secretory system is thought to be a dissociative process in which vesicles bud from one compartment and fuse with another. We studied the transport kinetics of phytohemagglutinin (PHA) and tonoplast intrinsic protein (TIP) in mesophyll protoplasts obtained from transgenic tobacco plants transformed with genes encoding these two proteins. In pulse-chase experiments, arrival of PHA in the vacuole was found to be slower (completed 24 hr after synthesis) than the arrival of TIP in the tonoplast (completed 6 hr after synthesis). Brefeldin A and monensin block protein transport by interfering in specific vesicle transport steps. Brefeldin A prevents anterograde vesicle transport between the endoplasmic reticulum and the Golgi, whereas monensin inhibits correct sorting in the trans-Golgi network by disrupting the proton gradient across the membrane. Both inhibitors blocked the transport of PHA to the vacuole and altered the rate at which its complex glycan is processed by Golgi enzymes. Neither drug stopped the arrival of TIP in the tonoplast, suggesting that the flow of vesicles continues in the presence of these inhibitors. We suggest that soluble proteins like PHA and membrane proteins like TIP reach their vacuolar destinations by different paths.     

Observations of the Leaf Cell Vacuole of Stevia rebaudiana Bertani Under the Electron Microscope

By applying electron microscopic technique, we aimed to observe the morphology of leaf cell vacuole of Stevia rebaudiana Bertani, and the change of inclusion during its different stages of growth. We ascertain that the size of vacuoles is small in younger leaf cell, that the number of vacuoles is more than that in other stages, and that vacuoles appear translucent, either round or elliptical in form. Also those leaf cells that are at the stage of active growth appear to have many morphologically specialized vacuoles containing a lot of inclusions in different forms of granule and vesicle. Furthermore, the inclusion of the vacuols in the elder leaf cells decompose gradually, eventually disappear. Comparing with the substructural observation of chloroplast, by PAS reaction, and with different content of steviaside, we discover that there exists corresponding relationship. Thus, we may infer that steviaside is stored mainly in the vacuoles and it is relevant with the function of production.     

抗病品种中小麦条锈菌细胞的超微结构变化过程

本文就寄主抗病性表达过程中,小麦条锈菌细胞的超微结构变化进行了系统地观察研究。结果表明:胞间菌丝的细胞壁染色逐渐加深,厚度加宽,结构疏松,形成小空洞,并逐渐解体;细胞质逐渐凝聚、脂肪粒的数量增多、有黑色颗粒状沉积物积累;细胞质中小囊泡数目增多并逐渐融合成大液泡,线粒体数目增多,并逐渐肿胀和解体。次生吸器畸形,初生吸器体呈圆球形。吸器壁加厚,染色加深;在吸器的中央,细胞质逐渐分解而形成空泡;线粒体数目增多,并逐渐肿胀和解体;吸器外质膜呈皱褶状,吸器外间质加宽,其中有大量的丝状或颗粒状内含物形成;吸器形态结构的变化均早于其胞间菌丝。     

FINE STRUCTURE OF CAPITULAR FILAMENTS IN THE COENOCYTIC GREEN ALGA PENICILLUS1,2,3

Capitular filaments of Penicillus capitatus contain a large central vacuole. The parietal cytoplasm is densely packed, devoid of chloroplasts in the growing tip, and becomes convoluted and sponge-like as extensions of the vacuole penetrate the cytoplasm in mature portions of the filament. Structure of organelles and their distribution in the filament are described. The vacuole contains a variety of inclusions, such as membranous configurations, spherical bodies, electron dense bodies, and calcium oxalate monohydrate crystals, each of the latter surrounded by a chamber associated with microtubules. Endophytic bacteria are present throughout the vacuole and occasionally in the tip cytoplasm. Some vacuolar components of P. pyriformis are described for comparison.