槐种子发育过程中子叶细胞显微结构的变化和过氧化物酶同工酶变…

槐（Ｓｏｐｈｏｒａ ｊａｐｏｎｉｃａ Ｌ．）种子发育过程中,子叶细胞大量合成和积累储藏物质,光镜和电镜下用组织化学观察到开花后３０ｄ,叶肉细胞高度液泡化,其中分而着大量的质体、粗面内质网、一些线粒体的小脂体。淀粉开始积累。开花后６０ｄ,淀粉和脂体不断长大,数量明显增多,液泡中蛋白体开始形成。从花后９０ｄ开始,液泡中有大量蛋白体形成且不断长大,有些蛋白体变得不规则形。至种子成熟期,叶肉细胞几乎完全被     

西瓜种子发育和萌发过程中子叶细胞超微结构的变化

西瓜种子子叶内贮存物质开始积累时,细胞质内有大量核糖体、质体、线粒体,内质网片段和囊泡,种子脱水期至成熟期,细胞器的数量减少,成熟种子子叶细胞的细胞壁不连续,几乎观察不到细胞器的存在,种子萌发过程中内质网,线粒体,质体的数目逐渐增多,叶肉细胞的质体发育成叶绿体,种子形成过程中,在子叶细胞大液泡分隔的同时,膨胀的内质网囊泡内积累蛋白质（直径0.1-0.4μm),这些小的蛋白质球体最终进入液泡形成大的蛋白体（直径1-3μm);萌发种子贮存蛋白质被水解的同时,一些脂体进入液泡并被分解,同时液泡融合;脂类物质开始积累的时间早于蛋白质,积累的量较蛋白质多,但在萌发种子中被彻底水解的时间晚于蛋白质,淀粉粒的数量在种子形成时减少,种子萌发时在表皮细胞和叶肉细胞内都重新合成。     

花生荚果发育过程中子叶细胞的超微结构和脂酶活性的研究

在花生(Arachis hypogaea)荚果发育过程中,子叶细胞的超微结构和脂酶活性皆发生了显著变化。子叶生长初期,缅胞中质体较多,并不断形成淀粉粒;脂酶活性低,脂体和蛋白体很少。子叶发育中期,子叶细胞质中出现大量体积较大的脂体,液泡中的蛋白体不断形成和增大,而且细胞质、内质网、蛋白体外膜、细胞质膜和细胞间隙上皆显示较强的脂酶活性。子叶发育后期,脂体数量不再增加,但体积略有增大,间质透明度也有提高;蛋白体增大较小,但数量却进一步增多;细胞质中仍显示较强的脂酶活性。至末期时,蛋白体形态变得不规则,甚至出现部分解体,其基质充挤脂体间隙;细咆中的脂酶活性减弱。研究表明,花生脂体起源于细胞质,蛋白体起源于液泡,子叶油分和蛋白质的积累足体内脂体和蛋白体不断发育的结果,细胞中脂酶活性的变化可能与脂体发育有关。     

拟南芥菜(Arabidopsis thaliana)子叶中蛋白体形成的超微结构和免疫电镜定位研究

本文对拟南芥菜(Arabidopsis thaliana)种子发育过程中贮藏蛋白的积累和蛋白体的形成进行了超微结构和免疫电镜定位的研究。常规超薄切片的电镜观察表明,在开花后第10天(10 DAF),高电子密度的蛋白质物质开始在子叶细胞的液泡中沉积。这一过程一直延续到种子接近成熟(14 DAF),这时液泡中充满了蛋白质物质,转变成为大的蛋白体。利用了该种植物主要种子贮藏蛋白之一的12 s球蛋白的单克隆抗体作为免疫探针,以蛋白质A-胶体金电镜技术对12 s种子蛋白进行了细胞内定位,证实了在液泡中积累的物质为种子贮藏蛋白。实验结果表明在拟南芥菜中,子叶细胞中的液泡是蛋白体的前体,肯定了蛋白体的发生起源于液泡的观点。本文还对应用胶体金电镜技术进行细胞内定位的某些问题作了初步探讨。     

甘蓝型油菜(Brassica napus L.)胚胎发育过程中子叶叶肉细胞的超微结构观察

用透射电镜观察了开花后20天、30天和50天的甘蓝型油菜子叶叶肉细胞的超微结构。鱼雷形胚时子叶细胞中富含核糖体和内质网并开始形成脂体。蛋白质的积累迟于油脂,开花后30天时液泡中出现蛋白质体。胚成熟时细胞中大量脂体相互挤压成多边形并围绕在蛋白质体周围,少有细胞器。整个观察过程中质体始终缺乏精细的片层结构,胚成熟时细胞中质体数显著减少。对质体在胚胎发育过程中的功能及其与低亚麻酸育种的关系进行了讨论。     

蓝猪耳花药发育中多糖和脂滴的组织化学研究

对蓝猪耳花药发育中营养物质的分布和转化过程进行组织化学研究,结果表明:在造孢细胞时期,药壁细胞没有营养物质的积累,但在造孢细胞中有少量的脂滴;在小孢子母细胞时期,表皮细胞中出现淀粉粒,而在绒毡层细胞中出现脂滴,小孢子母细胞中也有脂滴的分布;在四分体时期,四分体小孢子中出现淀粉粒,绒毡层细胞脂滴增加;在小孢子早期,药室内壁细胞中出现淀粉粒,绒毡层继续积累脂滴,而小孢子中开始出现脂滴;到小孢子晚期,绒毡层细胞降解,细胞残留物中出现较多脂滴;在二胞花粉早期,花粉中的大液泡消失,花粉开始积累淀粉粒;在即将开花的成熟花粉中则积累了大量的脂滴和少量的淀粉粒.蓝猪耳花药发育中多糖和脂滴两种营养物质的积累和分布具有一定的时、空特点,反映出花药发育中营养物质积累的规律.     

枸杞花药发育过程中脂滴和淀粉粒的分布特征

宁夏枸杞(Lycium barbarurn L．)花药发育过程中,淀粉粒和脂滴两种营养物质的积累和分布具有一定的特点：在造孢细胞时期,药隔薄壁细胞,表皮和药室内壁细胞中开始积累淀粉粒,而造孢细胞、绒毡层细胞和中层细胞中则没有淀粉粒。在四分体时期,绒毡层细胞开始积累脂滴并且数量逐渐增加。到小孢子晚期,绒毡层细胞降解,内含脂滴流入药室中。在小孢子发育过程中既没有淀粉粒也没有脂滴积累,直到二胞花粉的大液泡消失后花粉粒中才开始积累脂滴,然后又开始出现淀粉粒。枸杞成熟花粉中的营养储存物是脂滴和淀粉粒。     

绞股蓝营养器官中皂苷积累组织的超微结构观察

应用超薄切片和电镜技术观察了绞股蓝营养器官中积累皂苷的叶肉细胞、茎表皮细胞、茎皮层细胞和茎韧皮部细胞的超微结构.结果表明,幼叶叶肉细胞的液泡中具有蛋白体性质的电子致密物;随着叶的发育,叶绿体结构逐渐完善并积累淀粉粒;地上茎表皮细胞的外侧壁增厚,皮层细胞含叶绿体,液泡内有团块状结构;根状茎中的筛管细胞具有囊泡结构,其内的颗粒状内含物可释放至液泡和跨壁运输;韧皮薄壁细胞近细胞壁处具有丰富的细胞质和细胞器.但上述细胞中均未发现与皂苷积累相关的特殊电子致密物.     

春秋花生种子细胞化学的比较研究

采用泉花10号,汕油71的春秋花生种子为材料,利用细胞化学方法,在环氧树脂厚切片中分别显示出下胚轴和子叶中的多糖、蛋白质和脂类,并对其数量、形态及分布进行比较.结果表明,春花生种子下胚轴细胞较大,且内部结构清晰,排列规则,发育充分,而秋花生种子成熟度较低.对于子叶细胞,在春花生中,其贮藏物质丰富含大量的脂体、蛋白体,排列紧密;而秋花生细胞内部结构疏松,液泡中尚未充满蛋白质,但淀粉粒似较多.这就从细胞学的角度解释了生产上采用春花生种子的优越性..另外,在方法上对环氧树脂厚切片中多糖、蛋白质、脂类的细胞化学染色方法和染色保存进行了讨论.     

黄连木果实中油体的发育

黄连木（Pistacia chinensis）是一种重要的木本油料植物,其果实中贮存着大量的油脂,这些油脂分子主要存在于果皮、种皮和胚的油体中。在光学显微镜下观察发现,果皮中油的积累开始于果实发育晚期,果皮开始变红时;种皮中油体的发育开始于果实发育早期;胚中油体的发育开始于球形胚时期。透射电子显微镜观察结果显示,种皮和胚中的油体形成于内质网,而果皮中的油体则分别由内质网、质体和液泡形成。尼罗红荧光标记显示,内质网形成的油体始终以独立单元的形式存在。种皮和胚中也贮藏蛋白体,但发育晚于油体。果皮、种皮和子叶中都贮存少量的淀粉粒。     

Ultrastructure and Lipase Activity of Cotyledon cell During Pod Development in Peanut

A series of significant changes of the ultrastructure and lipase activity of cotyledon cell were found in peanut (Arachis hypogaea) during pod development. In he initial stage of cotyledon development there were many plastids which kept producing starch grain and there were low lipase activity and very few lipid and protein bodies in the cell. In the middle stage of cotyledon development, a great number of larger lipid bodies were seen in the cell and a lot of protein bodies formed in the vacuoles and continued to increase in size. Lipase activity increased in the cytoplasm, endoplasmic reticulum, protein bodies, plasmalemma and intercellular space. In the later stage of cotyledon development, the lipid bodies did not increase in number but became slightly larger. The protein bodies continued to increase both in number and in size. Lipase acttvity was even hegher in the cytoplasm. In the final stage the protein bodies became irregular in shape and some of them tended to disintegrate with their content entered into the space around the lipid bodies. The lipase activity in the cell declined. The results indicated that the lipid body originated in the cytoplasm and the protein body originated in the vacuole; that the accumulation of oil and protein in peanut cotyledon resulted from the formation and development of lipid and protein bodies in the cell, and that the changes of plasmid and lipase activity in the cell played a role in the development of lipid body during the development of cotyledon.     

两种品质类型花生品质形成与子叶细胞超微结构的关系

在大田条件下研究了两种品质类型花生(Arachis hypogaea)品质形成的动态差异及其子叶细胞超微结构的差异。结果表明, 高蛋白品种‘XB023’的蛋白质含量在籽仁发育前期较高油品种‘鲁花9号’低, 后期显著高于‘鲁花9号’, 且成熟期籽仁8种必需氨基酸组分含量均高于‘鲁花9号’, 其中谷氨酸、赖氨酸和亮氨酸含量差异极显著; ‘XB023’脂肪含量在籽仁发育期一直低于‘鲁花9号’。‘XB023’各时期的籽仁可溶性糖含量和油酸/亚油酸(O/L)值均显著低于‘鲁花9号’。两品种在果针入土10天时子叶细胞即形成淀粉粒、脂体和蛋白体, 随后脂体、蛋白体的数量不断增加, 淀粉粒先增大后逐渐缩小解体。‘XB023’的脂体达到最大的时间早于‘鲁花9号’, 而‘鲁花9号’的脂体快速积累的时间比‘XB023’长。两品种蛋白体大小都在果针入土40天时达到最大值, ‘XB023’的蛋白体在籽仁发育后期数量增加较快。高蛋白品种较高的蛋白质含量由其子叶细胞中较大蛋白体的大小和较多的蛋白体数量决定, 而高油品种较高的脂肪含量是由其较多的脂体数量决定。     

Distribution and changes of reserve materials in cotyledon cells of Panax ginseng related to direct somatic embryogenesis and germination

Cotyledon explants from zygotic embryos of Panax ginseng produced somatic embryos on Murashige and Skoog basal medium without growth regulators. Somatic embryos developed directly from epidermal cells at the cotyledon base. Somatic embryos were always formed from the side of the cotyledon opposite to the one attached to the medium surface regardless of cotyledon orientation. The frequency of somatic embryo formation from the abaxial epidermis (66%) was much higher than that from the adaxial epidermis (12%). Differences in embryogenic response were likely related to cell structure. Abaxial epidermal cells were filled with reserve materials (lipid bodies), while adaxial epidermal cells were devoid of any prominent reserves. During germination, the reserve materials in the cells of the cotyledons disappeared rapidly. At the same time, the competency of somatic embryo formation from cotyledon explants declined rapidly to zero. Upon culture of the cotyledon explants (for somatic embryo induction), lipid bodies slowly disappeared, but starch grains accumulated prominently. Reserve materials disappeared after commencement of embryogenic cell division. During germination, lipid bodies rapidly disappeared, and chloroplasts developed instead of starch grains. Received: 29 January 1997 / Revised version received: 16 April 1997 / Accepted: 9 May 1997     

ULTRASTRUCTURAL CHANGES ASSOCIATED WITH UTILIZATION OF METABOLITE RESERVES AND TRICHOME DIFFERENTIATION IN THE PROTOCORM OF VANDA

Certain aspects of protocorm development in Vanda were examined ultrastructurally. The parenchymal cells of the protocorm accumulate substantial quantities of lipid, protein, and carbohydrate reserves which disappear gradually with the senescence of the parenchymatous region. The proteinaceous reserves appear initially as discrete bodies which become intimately associated with clusters of small tubules. The tubules eventually disperse throughout the cytoplasm and disappear following depletion of the protein bodies. The lipid reserves also appear as discrete bodies and are associated with an electron dense, laminated inclusion which appears to increase in size with the disappearance of the lipid bodies. While plastids in the meristematic cells differentiate a well-developed thylakoid system and contain little starch, those of the parenchymal cells contain large starch grains and numerous osmiophilic droplets and develop meager thylakoid systems. Membrane-bound crystalline structures of hexagonal and rhomboid cross section occur frequently in the cytoplasm of senescent parenchyma cells. Trichome initials, which differentiate from the epidermis, contain few conventional organelles and exhibit numerous membrane-bound structures containing many small crystalline inclusions. Numerous vesicles accumulate at the tips of the trichomes in spaces between the cell wall and the plasmalemma.     

冠果草种子萌发过程的组织化学动态

冠果草的种子中没有胚乳,营养物质贮藏在胚中,其成分主要是淀粉和蛋白质。胚各部分的物质积累情况差异较大,子叶和下胚轴细胞中的淀粉粒、蛋白体数目多、体积大,胚芽和胚根分生细胞中则只贮藏少量的淀粉粒、蛋白体。在种子萌发过程中,胚各部分的淀粉粒逐渐解体,至二叶幼苗期全部消失。蛋白体的降解有严格顺序,远离胚芽的细胞中蛋白体降解较早,胚芽附近细胞中的降解较晚,而且胚芽细胞中还有新的蛋白体形成。单个蛋白体的降解     

The Cytological and Histochemical Studies of Developing Soybean,Cotyledons

In the late globular proembryos, three regions could be identified, i. e. the cotyledon primordium, the epiphysis and the hypocotyl-hypophysis. In the cotyledon primordia, the mitotic frequency of the cells was comparitively high, the directions of the mitotic planes were mostly perpendicular to the long axis of the embryo, the size of the nucleolus was comparitively large, and the cytoplasm density was high. In the epiphysis region, however, the mitotic frequency of the cells was low, the size of the nucleolus was small, and as the first pair of leaf primordia appeared the mitotic frequency of the cells in that region began to increase. In the hypocotyls hypophysis region the mitotic frequency of the cells as well as the size of the nucleolus lied in between the corresponding values of those of the above two regions, the cytoplasm density was low and the size of the vacuoles was large. As the proembryo continued to develop the direction of the mitotic plane changed gradually, from mostly perpendicular to the long axis of the embryo to mainly inclined, or even parallel to that axis. As a result, the proembryo developed from a heart-shaped embryo into a torpedo-shaped embryo. After the first pair of leaf primordia appeared from the young embryo, the vacuoles in the cells of the cotyledons grew in size rapidly. About twenty to twenty five days after flowering, the starch grains, the protein bodies and the lipid granules began to accumulate in the cells of the cotyledons and gradually increased both in size as well as in quantity. About fifty days after flowering the diameter of the starch grains reached its maximum value of 6.2–7.0 μm, and decreased in value thereafter till the time of harvesting when most of the starch grains disappeared except those in the palisades. On the other hand, fifty to sixty days after flowering, the diameters of the lipid granules and of the protein bodies reached their maximum values of 5.4–7.0 μm and 6.2–7.0 μm, respectively. The observation revealed that the formation of the protein bodies was related to the vacules.     

Correlation between Protein Body Formation and Storage Protein Accumulation in Soybean Cotyledons

At 20 days after flowering (DAF), the 7S α' and α subunits began to accumulate. At 25 DAF, the 7Sβ, l1SA and llSB subunits appeared. Five days later, the 11SA-4 subunit was present During the period of 25–55DAF, the storage protein content continued to increase. From 55 to 63 DAF, there was a decrease in the synthetic rate of the storage proteins. Comparing these results with the two paths of protein body formation reported previously, we draw the conclusion that the protein bodies developed from vacuoles contained not only the 7S bm also the lis proteins in soybean cotyledon cells.     

SEASONAL CHANGES IN THE APICAL ZONATION AND ULTRASTRUCTURE OF COASTAL DOUGLAS FIR SEEDLINGS (PSEUDOTSUGA MENZIESII)

The apical meristems of one-year-old container-grown seedlings of coastal Douglas fir were studied in two years during embryonic shoot development, dormancy, and dormancy release by light and electron microscopy. Apical zonation was evident at all times but prominence of some zones varied. Vacuolation was an important zone-characteristic and was not an artifact created by lipid extraction. During late summer and fall the plasma membrane was relatively smooth, ER not abundant, nuclear membranes irregular, and lipid bodies sparse. Numerous autophagic vacuoles occurred in apical cells. These diminished after bud scale initiation was completed in September and reappeared again in midwinter. Maximum starch accumulation was in the fall then it decreased during the winter and remained low during cold storage. The number of lipid bodies gradually increased in late fall and was large in winter. A single night of –1 C caused an increase in the number of lipid bodies. Plastids contained electron-dense material which accumulated further under subfreezing temperatures and eventually appeared to be released during winter into the cytoplasm and arranged into small globules along the cisternae of the ER. Granular protein bodies were observed at this time as well as deposits of electron-dense material on the outer surface of the plasma membrane and in cell walls. During winter, the plasma membrane became convoluted, short cisternae of the ER abundant, the nuclear membranes evenly separated, and nucleolar components aggregated. At the end of dormancy, ribosomes and starch grains became very abundant. Most lipid bodies diminished by budbreak.