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。     

感染大麦黄花叶病毒(BaYMV)的大麦细胞质内含体及细胞器病变的研究

超薄切片电镜观察表明,在感染大麦黄花叶病毒(BaYMV)的大麦(品种“早熟3号”)叶肉细胞中,液泡周围偶而可看到病毒颗粒束,在发病后期黄化或坏死的叶肉细胞中,可见到散布的病毒颗粒。在所有表现症状的病叶叶肉细胞,表皮细胞和木质部薄壁细胞中均可观察到风轮体、束状体、板状集结体以及膜状体等细胞质内含体,未见 卷简体和细胞核内含体。感病初期细胞中,细胞质丰富,核糖体数量增加,内质网肥大,随着病毒症状发喂,叶绿体、线粒体等细胞器逐渐肿大,外膜破裂直至解体。     

盐胁迫下芦苇叶肉细胞超微结构的研究

对青藏高原柴达木盆地柯柯盐湖边盐碱地上生长的芦苇叶肉细胞的超微结构进行了研究,并以西宁地区非盐碱地上生长的芦苇作对照。结果表明：西宁地区的芦苇叶肉细胞的叶绿体呈椭圆形,其膜系统完整,基粒片层和基质片层发育良好。在盐碱地上生长的芦苇叶肉细胞的叶绿体呈圆形,叶绿体内出现较大的淀粉粒,并发现有线粒体嵌入叶绿体的现象。叶绿体的类囊体膨大,线粒体的嵴也有膨大的现象。在盐湖水中生长的芦苇叶肉细胞,叶绿体的类囊体排列紊乱、扭曲、松散。类囊体膜局部被破坏,部分类囊体膜解体,空泡化,甚至消失,一些溶解了的类囊体流进细胞质中。综上所述,芦苇叶肉细胞超微结构的变化是该植物适应柯柯盐湖地区盐渍、低温、低气压、强辐射等环境因子的结果。     

不同抗性的榨菜在芜菁花叶病毒感染后细胞超微结构的研究

超薄切片观察表明,在三种感染芜菁花叶病毒的榨菜叶肉细胞内均发现有各种形状的内含体和病毒粒子的存在。内含体形状有风轮状、束状、管状、环状和板状聚集体,且不同抗性的榨菜品种细胞内所含的内含体数量、种类及所占的比例亦不同,抗性较弱的９０－１４９榨菜品种叶肉细胞内内含体数量较多,以管状及环状内含体所占比例为多,束状及风轮状内含体所占比例较少;抗性较强的９０－１３９榨菜品种叶肉细胞内内含体数量较少,且以束状及风轮状内含体所占比例较多,环状及管状内含体所占比例较少。而抗性中等的９０－１４６榨菜品种叶肉细胞内内含体数量及所占比例介于上述两者之间。病毒粒子也以易感病的９０－１４９榨菜叶肉细胞内含量最多,均以束状或拟晶格状存在。此外感病初期细胞内线粒体及粗面内质网数量有不同程度的增多,且以易感病的品种叶肉细胞内这些细胞器增加明显,但健康植株内以抗性较强的品种含这些细胞器较多。随着病毒症状的发展,叶绿体畸形,肿大,基质消失,外膜破裂直至解体。     

向日葵幼叶及其培养的愈伤组织细胞的超微结构研究

通过超微结构的观察,向日葵幼叶及其经培养后10天的愈伤组织细胞之间有明显区别。叶肉细胞的细胞质、细胞器及核的结构和发育都比较完整。当外植体组织发生变化和愈伤组织形成时,观察到线粒体相互连接成链状围绕在叶绿体周围,而叶绿体有的围绕在核的周围;线粒体的嵴和基质,叶绿体的基粒和片层结构常发生退化或解体,细胞质稀薄,核糖体和胞质凝成线状或网状,微体和高尔基体消失,液泡化程度高并含有较多的次生物质;而细胞核在后期才发生明显变化,轮廓不够清晰。     

沙冬青冬季叶绿体的超微结构特征

沙冬青在冬季的叶肉细胞中有丰富的叶绿体,经常聚集在一起,相互重叠,相互嵌合,有的还相互融合。大部分叶绿体为凸透镜形,多余叶绿体主要为V形、蝶形、连婴形和哑铃形。它们的被膜不光滑,常凹凸不平,甚至出现突起和内陷。类囊体十分发达,质体小球很多,但淀粉粒缺乏。大部分叶绿体形态结构正常,有的还在出芽和分裂。少数叶绿体与此不同,它们已经衰老,其中一些正在解体或已经解体。     

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.     

用感染病毒细胞超微结构的差异区分RMV及TMV株系

通过透射电镜观察被长叶车前草花叶病毒(RMV)和烟草花叶病毒(TMV)不同株系感染的普通烟叶肉细胞的超微结构,发现两种病毒的粒子分布、内含体类型、被感染细胞超微结构的病变均存在差异.病毒粒子分布有成束、分散、环状、膜包被及角状成层或平行成层排列等类型,存在于细胞质及液泡中,但未见于细胞核、线粒体及叶绿体等细胞器中.内含体的X-小管形状有长杆状、短杆状及颗粒状,数量各异.细胞壁常引起增厚、结构松散及扭曲等变化.叶绿体聚集成堆或分布于细胞边缘,其数量、大小、形状及所含淀粉粒、嗜锇颗粒等存在差异,有些还有颗粒状物质积累.线粒体及内质网等在不同株系间也存在差异.本项研究表明,被感染细胞超微结构的差异可作为RMV和TMV株系区分的依据.     

沙冬青冬季叶绿体的超微结构特征

沙冬青在冬季的叶肉细胞中有丰富的叶绿体,经常聚集在一起,相互重叠,相互嵌合,有的还相互融合。大部分叶绿体为凸透镜形,其余叶绿体主要为Ｖ形,蝶形、连婴形和哑铃形。它被膜不光滑,常凹凸不平,甚至出现突起和内陷。类囊体十分发达,质体小球很多,但淀粉粒缺乏。大部分叶绿体形态结构正常,有的还在出芽和分裂。少数叶绿体与此不同,有的还在出芽和分裂。少数叶绿体与此不同,它们已经衰老,其中一些正在解体或已经解体。     

细叶黄芪叶肉原生质体发育早期几种细胞器的变化

在细叶黄芪叶肉原生质体发育早期,细胞器的变化较大。离体培养4h后,线粒体的嵴和基质物质开始增加。培养3—5天后,线粒体的数量增加5倍以上,此时可见大部分线粒体围绕细胞核分布。在培养24h后,高尔基体开始发育,它们主要分布在细胞质周边区域。多糖细胞化学染色表明,高尔基体内沉积着大量嗜银物质。培养1天后,粗面内质网开始发育。培养3天时,部分叶绿体边缘出现一些空隙结构。随着叶绿体内膜结构的消失,淀粉粒增大,叶绿体逐渐转变为造粉质体。     

Ultrastructure of the excretory tubes of the mite Macrocheles muscaedomesticae (Mesostigmata,Macrochelidae) with notes on altered mitochondria

The fine structure of the excretory tubes of the mesostigmatid mite Macrocheles muscaedomesticae were investigated. These paired tubes are partially ensheathed by fat body and invested throughout by a branching system of visceral muscles. The fine structure of the cells of the excretory tube is in general similar with only minor differences found throughout its length. The basal region of each epithelial cell of the excretory tube borders the hemocoel and is divided into many compartments by the extensive infolding of the plasma membrane. Mitochondria and vacuolar inclusions are often closely associated with these compartments. More than one morphological type of mitochondria was found distributed throughout the cells of the excretory tubes. The most commonly encountered type had well developed cristae and an electron dense matrix. Less commonly, mitochondria with somewhat poorly developed cristae and a translucent matrix often containing myelin-like figures of varying complexity were observed. It is suggested that they represent part of a normal process of mitochondrial degeneration. The apical region of the cell has a border composed of plate-like folds of the plasma membrane termed microlamellae. The lumen contains abundant granules of the excretory product.     

沙冬青叶肉细胞中一种特殊内含物的发育

用透射电镜观察了沙冬青（Ａｍ ｍ ｏｐｉｐｔａｎｔｈｕｓｍ ｏｎｇｏｌｉｃｕｓ）叶肉细胞中一种电子密度很高的近似椭圆形的特殊内含物的发育． 它始于中央液泡外侧,起初只是少量的泡状成分和电子密度很高的物质,然后两种成分逐渐增多,并随液泡膜内吞形成突起,不断伸向液泡中央,有的突起占据了液泡很大一部分体积． 接着突起中的泡状成分开始解体,电子密度很高的物质越来越多,直至充满整个突起． 当突起继续内伸时,它的尾部不断收缩变小,最后完全脱离液泡膜而游离在中央液泡里面． 这种内含物一般只出现在严冬季节,里面含有大量的脂．     

Shoot Growth and Changes in the Mesophyll Cell Structure in the Biennial Needles of Abies sibirica Ledeb.

Structural aspects of source–sink relations in current-year and second-year shoots of Siberian fir were investigated. The period of linear growth of current-year shoots was accompanied by a decrease in the size of starch granules in chloroplasts and the number of mitochondria, as well as by the disappearance of lipid inclusions in the mesophyll cells of second-year needles. Growth processes did not affect seasonal changes in the structure of chloroplast grana in these cells. After the termination of shoot growth, large polysaccharide globules appeared in the cytoplasm of mesophyll cells in second-year needles. It is possible that the formation of these inclusions prevents the inhibition of the photosynthesis by starch, which was accumulated in chloroplasts.     

Ultrastructural pathology of leaf cells of ryegrass (Lolium multiflorum) infected with ryegrass mosaic virus.

Ryegrass mosaic virus particles and virus induced lamellar inclusions were found in mesophyll and epidermal cells of virus infected ryegrass leaves. The lamellar inclusions were occasionally found in phloem cells also. Virus particles occurred in cytoplasm, inside plasmodesmata and often in membrane bound sacs embedded in a matrix between plasmalemma and cell wall at or near plasmodesmata. Electron dense plugs protruding from plasmodesmata, finger-like cell wall outgrowths and cell wall deposits usually at plasmodesmata were also observed. Cytopathological changes in organelles in infected cells included dense deposits in the cisternae of endosplasmic reticulum and Golgi apparatus, mitochondria with electron-dense or opaque matrix, proliferating cristae and deteriorating unit membrane; and disintegrating chloroplasts.     

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.     

沙冬青淀粉粒及其与叶绿体发育的关系

沙冬青叶绿体中的淀粉粒一般为１－３个,主要有４种类型。第１种外周部分电子密度较高,中央部分较低,但每个部分的电子密度十分均匀。它们近似椭圆形,附近的类囊体形态正常,结构清晰。第２种电子密度由外向内逐渐变低,多为椭圆形,附近的类囊体较清晰。第３种外周部分的电子密度很高,中央部分不均匀,形状多种多样,附近的类囊体有的不清晰。第４种电子密度很低,十分均匀,形状不规则,附近的类囊体已经解体或正在解体。分析表明,淀粉的形态变化明显与叶绿体发育有关。     

Ultrastructure of mitochondria in the corpora allata of honeybees infected by Nosema apis before and after treatment with anti-Nosema drugs

Ultrastructural differences were observed among mitochondria from the corpora allata of healthy, Nosema-infected, and anti-Nosema drug treated honeybees. Mitochondria in the corpora allata of the healthy honeybees were large in size, possessed well defined membrane, numerous mitochondrial granules and less electron-dense matrix. In the corpora allata of Nosema-infected honeybees, mitochondria were small in size and the mitochondrial matrix had a higher electron density. Mitochondria from the corpora allata of Nosema-infected honeybees after treatment with thimerosal, had a lower electron density in the mitochondrial matrix and a larger diameter than those from untreated honeybees. Mitochondria from fumagillin-treated honeybees had the smallest diameter and the highest electron density in the matrix among mitochondria observed in the present study. Image analysis also confirmed the differences in the electron density of the mitochondrial matrix among mitochondria in the corpora allata of four experimental groups of honey bees.