DETERMINATION OF RHIZOID ORIENTATION BY LIGHT AND DARKNESS IN GERMINATING SPORES OF ONOCLEA SENSIBILIS

When spores of the fern, Onoclea sensibilis L., are allowed to germinate in darkness, the rhizoid and the protonema are positioned at close to a right angle. If the spores are exposed initially to light and allowed to germinate, the rhizoid and protonema are positioned nearly axially, at opposite ends of the spore. The greater the duration and intensity of the initial illumination, the greater the tendency towards axial arrangement. All colors of light are active to some degree, and the effects are intensity-dependent. The response occurs in a uniform light field and is not dependent on a directional stimulus; the phenomenon reflects the relative arrangement of one part of the gametophyte to another part but not the orientation of growth with respect to an external stimulus. Direct tests show that neither the relative rhizoid orientation nor initial polarity of germination are affected by unilateral white light or polarized red light; the subsequent growth of the protonema, however, is oriented perpendicular to the plane of light polarization. The effects of light in determining the positional relationship between rhizoid and protonema are interpreted in terms of a hypothesis proposing light-induced changes in the structure and mechanical properties of the spore wall.     

ANALYSIS OF STARCH ACCUMULATION AND GERMINATION IN ONOCLEA SPORES

Previous studies have shown that low fluences of light accelerate starch accumulation and enhance germination of Onoclea spores. Fluence response curves for induction of starch accumulation were compared with fluence response curves for enhancement of germination in order to determine if the two photoresponses in Onoclea spores have a common photoreceptor. Fluence response curves indicate that both responses were proportional to the log of the fluence and that the relative fluence efficiencies of the four wavelength regions tested were similar for induction of both germination and starch accumulation. Red (600–720 nm) irradiation was the most efficient, while green (500–600 nm), blue (400–520 nm), and far-red (720–900 nm) irradiations showed a decreasing order of efficiency for induction of the responses. A correlation coefficient between the amount of starch accumulated as a result of red irradiation and the final percent germination was calculated to be 0.964. These results support the hypothesis that a common photoreceptor mediates both photoinduced germination and starch accumulation. 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) inhibits photosynthesis by blocking the flow of electrons from Photosystem II to Photosystem I. At 0.1 mM DCMU failed to inhibit both photoinduced starch acumulation and germination. This result and the greater efficiency of red than blue light, the low fluence functional for induction, and the fluence dependency argue against the participation of photosynthesis in photoinduced starch accumulation. A similar conclusion has been previously drawn for photoenhancement of Onoclea spore germination. Additionally, the effects 0.01–1.0 mm cycloheximide and 100 μl/l ethylene on photoinduced starch accumulation were investigated. Neither agent inhibited starch accumulation, whereas both substances inhibited germination 70–90% when applied at a time coincidental with the period of rapid starch accumulation. These results indicate that the photoinduction of starch accumulation does not have an ethylene sensitive stage nor does it require protein synthesis as does photoenhancement of germination of Onoclea spores.     

我国常见孢粉化学成分研究

本文对我国常见的15种花粉进行了氨基酸、磷脂、碳水化合物、维生素、矿物元素、核酸、胡萝卜素、黄酮素、生长素等的分析研究,为孢粉生油、孢粉热变质与油气成熟度、孢粉埋藏学、孢粉壁结构、抱粉生理学研究以及我国花粉资源的开发利用提供了重要的科学依据。     

THE USE OF TETRA- AND PENTA-CHLORONITRO-BENZENES IN THE CONTROL OF BOTRYTIS DISEASE AND RHIZOCTONIA ATTACK OF LETTUCE

Botrytis disease in the 'spring' lettuce crop was controlled by six talc dusts containing s, 10 or 20 % of tetra- or penta-chloronitrobenzene. All the dusts increased equally the final stand in the frames, but the number of seedlings with stem lesions decreased with increasing concentrations of both compounds. At similar concentrations the tetra- was more effective than the penta-compound. The percentage survival in the field was increased by the dust treatments. The 20% dust of the penta- was only as effective as the 5% dust of the tetra-compound.
The dusts affected the leaves, stunted the seedlings and delayed hearting. At similar concentrations the tetra- was more harmful than the penta-compound. The 5 % dust of the tetra- was less damaging than the 20% dust of the penta-compound.
The spread of Rhizoctonia solani was reduced by incorporating the dusts with soil. Again, the 5% tetra- dust was as effective as the penta- dust at 20%. At 12·5 g. of dust per 20 kg. of soil, none of the dusts retarded the rate of emergence of lettuce seedlings but the highest concentration of the tetra- series reduced the number emerging.
Foliage applications of two dusts, 5% tetra- and 20% penta- dusts, controlled the spread of R. solani.     

GROWTH AND DEVELOPMENT IN MICROCULTURE OF GAMETOPHYTES FROM STORED SPORES OF EQUISETUM

Spores of Equisetum telmateia Ehrh. retained 74% viability after two years of storage under glycerine at minus 10 C. Stored spores germinated, grew, and formed mature gametangia on mineral nutrient media in petri plates and in micro-cultures where detailed cytological observations could be made. Growing gametophytes were favorable materials for studies of mitosis, chloroplast replication, gametogenesis, and senescence.     

MICROSPECTROPHOTOMETRY AND THE PHOTORECEPTOR OF PHYCOMYCES I

By applying microspectrophotometry to the sporangiophore of Phycomyces blakesleeanus wild-type and the albino car-10(-) type II, absorption spectra were obtained for 1- to 5-day cultures. Spectra in the growing-zone of the wild-type during Stage IVb, taken from 0.1 to 3 mm below the base of the sporangium, show two distinctly different spectra: one is more characteristic of a carotene, the other of a flavin. Combined, these absorption spectra reproduce closely the action spectrum. For the albino car-10(-), which is deficient in carotenes, only the spectrum characteristic of lumichrome or a reduced flavin was found. A c-type cytochrome was isolated from both strains which, if coupled with a flavin, could permit a photoreversible oxidation-reduction system. Birefringent crystals were observed to be aligned in the growing zone in which the photoreceptor is believed to lie. Micro-spectrophotometry of these crystals shows absorption peaks similar to those of riboflavin crystals.     

缩球囊霉孢子萌发及细胞核在孢子和芽管中分布的研究*

本文研究了从本校分离的丛枝菌根真菌缩球囊霉Glomus constrictum的孢子萌发和萌发孢子的细胞核DAPI(46-diamidino-2-phenylindol)染色。结果显示,G. constrictum孢子直径为179.5-198.7μm ,顶生于产孢菌丝上。经表面消毒处理后,孢子在水琼脂平板上7天开始萌发。DAPI染色后,经稀释荧光计数,单个孢子细胞核数目约为5300,在孢子中无序分布, 细胞核直径约为9.9-11.2μm 。孢子萌发过程中,细胞核总数无明显变化,只是部分细胞核从孢子流向了萌发伸长的菌丝。     

新疆独山子油田原油中的孢子花粉

本文研究了新疆准噶尔盆地独山子油田原油中分离出的孢子花粉35属51种。基于原油中孢子花粉的研究,追溯了该含油区的油源并讨论了油气运移问题。根据原油中找到的孢子花粉化石来判断,准噶尔盆地西南含油区有两套油源岩系,即下一中侏罗统八道湾一头屯河组和渐新统安集海河组。     

乳腺癌及癌前病变血管生成相关分子的表达及意义

目的探讨血管生成异常与乳腺癌发生发展的关系。方法采用免疫组化方法检测30例正常乳腺,30例普通性增生,30例非典型增生（AH）,20例导管内癌,50例浸润性导管癌组织中微血管密度（MVD）、VEGF及受体Flk-1/KDR的表达变化。结果各组CD34、VEGF及Flk-1/KDR的表达程度不同,浸润性导管癌组最高。随病程演进,MVD增加（P〈0.05）,VEGF及其受体Flk-1/KDR在血管内皮细胞表达渐进增高（P〈0.05）,但在病程初期各主要指标改变不明显,显著变化始于AH阶段。MVD在AH与导管内癌组间差异不显著（P〉0.05）,VEGF及Flk-1/KDR的表达在AH与导管内癌组间有显著差异（P〈0.05）。结论血管生成在乳腺癌发生发展过程中起着重要作用,血管生成异常可能是乳腺癌发生过程中的早期事件。VEGF及其受体Flk-1/KDR的表达异常可能是乳腺普通性增生-AH-乳腺癌这一癌性转化过程中血管生成异常的主要始动因素,VEGF及其受体Flk-1/KDR可能成为乳腺癌早期诊断及治疗的分子靶标。     

BIOCHEMISTRY OF FERN SPORE PROTEINS: GLOBULIN STORAGE PROTEINS IN ONOCLEA SENSIBILIS AND OSMUNDA CINNAMOMEA

Onoclea sensibilis was found to contain globulin storage proteins of 2.0S and 11.3S. These globulins, comparable in size and subunit composition to the spore storage proteins characterized in Matteuccia struthiopteris (Templeman, DeMaggio, and Stetler, 1987), declined during imbibition and the initial stages of spore germination. Osmunda cinnamomea, a fern that is only distantly related to Matteuccia, also contained globulin proteins, but these had S values of 5.5 and 11.3. SDS-PAGE analysis revealed extensive differences in banding patterns of the 11.3S protein between Onoclea and Osmunda. This work indicates that while globulin proteins are important storage materials in a variety of ferns they exhibit considerable molecular heterogeneity. The observed heterogeneity in the globulin proteins may be a useful tool to explore evolutionary relationships in the ferns.     

LOCUS AND STATE OF AGGREGATION OF MYOSIN IN TISSUE SECTIONS OF VERTEBRATE SMOOTH MUSCLE

Structures with the characteristics of molecular myosin were identified by electron microscopy in tissue sections of vertebrate smooth muscle. No thick filaments of myosin were found regardless of preparative procedures, which included fixation at rest and in contraction, glycerine extraction, and storage at low pH prior to fixation. Absence of thick myosin filaments and presence of what appear to be myosin molecules is in accord with conclusions based on X-ray diffraction (3, 12) and birefringence data (4) from living smooth muscles at rest and in contraction. Explanations are provided for appearances thought by others (6, 20, 21) to represent thick myosin filaments. Our present observations are in accord with the model for smooth muscle contraction which we have previously proposed (1).