STIGMA OF NICOTIANA: ULTRASTRUCTURAL AND BIOCHEMICAL STUDIES

The aim of the present study has been to elucidate further the cytology of the glandular stigma of Nicotiana tabacum, the mechanism of the secretory process during stigma development and the biochemical composition of the exudate. The stigma consists of two distinct zones: a glandular zone formed by the papillae and 2–3 layers of cells (basal cells) immediately below them, and a non-glandular region formed by vacuolated cells which are in continuity with the transmitting tissue. The stigmatic exudate is a complex mixture of different chemical compounds such as proteins, saccharides, fatty acids and phenols. The role of stigma secretion is discussed in relation to pollen activation, recognition and pollen tube growth.     

扬子鳄胃的组织化学及超微结构研究

爬行动物胃的一般组织学和组织化学的研究资料较多,Luppa1对此作了较为详细的总结.超微结构方面,龟鳖类和蜥蜴类亦有报道2,3,鳄类的资料尚缺.扬子鳄(Alligator sinensisFuval)是我国现存惟一的特有鳄类,陈壁辉4等曾对其食性进行了细致的考察,也对胃的一般组织结构作了描述.作者拟从组织化学和超微结构方面对扬子鳄的胃作进一步的研究,以丰富比较组织和细胞学资料,同时也增进对扬子鳄进化位置及其食性适应性结构的认识.       

SOME HISTOCHEMICAL,ULTRASTRUCTURAL, AND NUTRITIONAL ASPECTS OF THE OVULE OF QUERCUS GAMBELII

Histochemical analyses of the ovule of Quercus gambelii show that the major food reserves (starch grains and lipids) are located almost exclusively within the outer integument. Vascular traces are present only within this integument which contains numerous, well-developed plasmodesmata. The inner integument is virtually devoid of any food reserves and has very few plasmodesmata. The ovule has a persistent chalazal extension of residual nucellar cells (called the postament) which projects into the embryo sac. Due to the above information and the fact that the synergids rarely contain starch and no plasmodesmata are present in the walls of any of the cells of the egg apparatus (Mogensen, 1972), it is concluded that the synergids play little or no role in embryo sac nutrition. Rather, it is proposed that the pathway of available food materials in the young ovule is from the outer integument to the chalaza and through the postament into the embryo sac.     

ENDOCYTOSIS OF LANTHANUM NITRATE IN THE ORGANIC ACID-SECRETING TRICHOMES OF CHICKPEA (CICER ARIETINUM L.)

The organic acid-secreting trichomes of chickpea (Cicer arietinum L.) were exposed to 2.5 mm lanthanum nitrate for 24 hr, and this concentration did not inhibit trichome secretion compared with that of controls. We subsequently used this nontoxic concentration of lanthanum to examine endocytosis. In the stalk cells of these secretory trichomes, exogenously applied lanthanum nitrate was present in cell walls and vacuoles, as well as within both invaginations in the plasma membrane and vesicles in the peripheral cytoplasm between the plasma membrane and the tonoplast. In the head cells, lanthanum nitrate was present in cell walls and in vesicles that form a layer in the cytoplasm around the edge of the head cells, but was not present in vacuoles. We propose that fluid phase endocytosis targeted to the vacuole takes place in the stalk cells and that endocytosis occurs in the head cells to remove excess plasma membrane after the fusion of secretory vesicles with the plasma membrane. This is the first demonstration of endocytosis in secretory trichomes.     

刺激内脏大神经引起的小强荧光(SIF)细胞的组织化学和超微结构变化

对豚鼠一侧内脏大神经进行电刺激后,显微分光光度术测量发现:(1)刺激侧腹腔神经节小强荧光(SIF)细胞的儿茶酚胺(CA)荧光强度较对照侧下降了35.6%±4.6%((?)±SE)。(2)在单胺氧化酶(MAO)反应后,刺激侧 SIF 细胞的平均光密度(O·D·值)较对照侧显著升高;在镁离子激活的腺苷三磷酸酶(Mg~(2 )-ATPase)反应后,刺激侧的 O·D·值较对照侧显著下降。对超微结构进行的立体学分析显示,刺激侧 SIF 细胞内颗粒小泡的体积密度(V_v)较对照侧下降29.6%。这些结果表明:(1)豚鼠腹腔神经节 SIF 细胞受交感节前神经纤维支配。(2)刺激这些神经纤维可促使 SIF 细胞释放 CA。(3)释放的 CA 主要来自颗粒小泡的贮存。(4)CA 的这一释放过程伴有细胞内 MAO 活性的升高及 Mg~(2 )-ATPase 活性的下降。这些细胞能对电刺激发生反应的事实提示:交感神经节中的成团分布型 SIF 细胞可以在应激状态下,通过释放 CA 参与对机体的内分泌调节过程。     

COMPARISON OF TETRAPLOID AND SINGLE GENE-INDUCED GIGAS VARIANTS IN CHICKPEA (CICER ARIETINUM). I. ORIGIN AND GENETIC CHARACTERIZATION

Two genetic variants with increased organ size were independently derived from diploid (2n = 2x = 16) chickpea (Cicer arietinum L.) line ICC 640. Radiation-induced mutant PM1101 had greatly enlarged leaves, leaflets, and pods, and an elongated stem with longer internodes but fewer nodes than ICC 640. F₁, F₂, and F₃ data from crosses with ICC 640 showed that the mutant characteristics of PM1101 were the pleiotropic effects of a single, recessive genetic factor. For purposes of comparison, tetraploid derivatives of ICC 640 were produced by colchicine treatment of seed. In the tetraploids, leaflets and pods were enlarged, but less dramatically than in PM1101. Enlarged pollen grains and stomatal guard cells, and increased guard cell chloroplast number were found in tetraploids but not in PM1101, while both variants produced fewer seeds than ICC 640. Mutant PM1101 and the tetraploids represent two very different manifestations of gigantism in chickpea.     

冬季水淹后洲滩钉螺组织化学与超微结构的变化

实验表明，冬季持续水淹６０天以上，湖沼地区洲滩钉死亡率增高，繁殖力下降。为探索其机制运用组织化学与透射电镜技术观察了受淹钉螺软体组织。结果显示：水淹３０、６０天螺体内糖原含量减少；ＡＬＲ、ｍｇ＾＋＋－ＡＴＰａｓｅ，Ｇ－６Ｐａｓｅ活性下降；ＳＤＨ．ＬＤＨ．ＡＣＰ活性增高；ＣＨＥ活性无明显变化。水淹６０天螺头足部软件 体与肝脏组织细胞肿胀并伴有线体肿胀，嵴断裂或空泡状变，粗面内质网脱颗粒，高尔基体囊状     

COMPARISON OF TETRAPLOID AND SINGLE GENE-INDUCED GIGAS VARIANTS IN CHICKPEA (CICER ARIETINUM). II. MORPHOLOGICAL AND ANATOMICAL LEAF CHARACTERS

Two genomic variants of a chickpea (Cicer arietinum L.) parental line have been developed which exhibit gigas characters. The two genotypes were the result of a single-gene mutation (gigas) and induced tetraploidy of a single parental line. The two genotypes plus parental strain were investigated to determine the similarity-of-effect of polyploidy and this single-gene mutation on leaf anatomy and morphology. Leaves consisted of two rows of alternatively arranged leaflets. Both the tetraploid and parental lines had the same mean number of leaflets per leaf while the gigas plants had fewer, but mean total leaf surface area was greater in the gigas plants. Quantitative comparison of mesophyll and vascular tissue and air space volume density (V_v) showed that leaves of the tetraploid plants had the greatest mesophyll cell density (V_vm) and least air space density. Mesophyll cell density was equal in the parental and single-gene mutant while parental leaves had the greatest vascular tissue density. The greater mesophyll cell density values of the polyploid were due to larger mean mesophyll cell size, not to greater cell numbers per unit area. Leaf models based on tissue density and leaflet size showed tetraploid plants had the greatest productivity potential per unit of leaflet surface area. However, if models were based on a whole leaf, gigas plants had the greatest productivity potential since they had larger total leaf area. The effectiveness of using structural models to predict physiological potential in plant tissues will be tested in future studies.     

高温培养条件下爪哇伪枝藻的生理特性和超微结构特征

荒漠生物结皮广泛分布于干旱区环境,高温是影响生物结皮中藻类生存的重要环境因子。在实验室培养条件下,以生物结皮形成和发育中的重要优势种爪哇伪枝藻(Scytonema javanicum Born et Flah)为材料,研究高温胁迫对伪枝藻生理生化特性和细胞结构的影响。设置了25℃(对照)、35℃、40℃和45℃等不同高温处理,测定了短期(6h)和长期(15d)高温条件下,S.javanicum的光合活性、光合色素、多糖含量和丙二醛含量以及细胞超微结构的变化。结果表明,S.javanicum最大光化学量子产量Fv/Fm和PSII有效光化学量子产量ΦPSII在35℃下表现出最大值。40℃高温明显抑制藻体叶绿素a合成,35℃处理促进了叶绿素a合成(高于对照值),而40℃处理明显促进了藻体类胡萝卜素合成,高于对照处理和35℃处理。随温度升高,S.javanicum丙二醛、胞内可溶性糖和胞外多糖含量呈现出逐渐增大的趋势。透射电镜切片显示,40℃高温明显破坏了藻体细胞超微结构,如原生质体出现絮状形态和空泡化,35℃处理则有利于细胞形态结构的保持和稳定。以上结果初步证实了S.javanicum能够较好地耐受适当的高温(35℃)。研究对于了解S.javanicum对高温环境的耐受程度及对高温的适应性具有一定的理论意义,并对利用荒漠蓝藻治理荒漠化具有实际指导价值。     

ULTRASTRUCTURAL CHARACTERISTICS OF SPORE GERMINATION IN THE MOSS DAWSONIA SUPERBA

The spore wall of Dawsonia superba has characteristics that, in many respects, are similar to those of other mosses except for the exine, which is layered in Dawsonia. Imbibed spores have a well-developed endoplasmic reticulum with dilated cisternae that are associated with vesicles at the periphery of the cell. Ribosomes on the surface of the vesicles suggest that many vesicles originate from the endoplasmic reticulum. Two types of protein storage bodies are observed: membrane bound protein bodies with a homogeneous matrix which gradually becomes vesicular, and densely stained and non-membrane bound bodies consisting of crystalline arrays of fibrils. As in spores of higher plants, the protein reserves disappear during germination and may be converted to starch and other materials needed for development of the gametophyte.     

人胎儿呼吸道肥大细胞的组化特征及其共与其它细胞的关系

用组织化学技术方法 ,我们对 5 0例不同胎龄人胎儿的鼻粘膜和气管的组织内的肥大细胞组织化学特征以及其与周围其它细胞的关系进行了研究。结果发现 :随着胎龄的增加 ,肥大细胞的颗粒甲苯胺蓝 (TB)染色时从浅紫色加深至深紫色 ,Alcian蓝·藏红 (AB· S)染色呈从蓝色到出现红色、红蓝混合染色的变化 ,临界电解质浓度 (CEC)值和硫酸小蘖碱荧光染色强度逐渐增高 ;多见肥大细胞与成纤维细胞、淋巴细胞和毛细血管内皮等密切接触 ,且出现在神经内、外膜之中。这提示 :1肥大细胞的发育成熟与胎儿呼吸道器官的发育是相关的。 2肥大细胞可能参与细胞、组织的分化成熟。