SEASONAL VARIATIONS OF PHOTOSYNTHETIC PIGMENTS, TOTAL C, N, AND P CONTENT, AND PHOTOSYNTHESIS IN PHYLLARIOPSIS PURPURASCENS: (PHAEOPHYTA) FROM THE STRAIT OF GIBRALTAR

Photosynthetic pigments, C, N, and P tissue composition, and photosynthetic rate were measured from April to October in the brown alga Phyllariopsis purpurascens (C. Agardh) Henry et South (Laminariales, Phaeophyta) growing at a 30-m depth in the Strait of Gibraltar. Ir-radiance reaching the population ranged from 13.5 to 27.5 mol.m^-2.mo^-1. The available light for this species, expressed as a percentage of the irradiance above the water, was 1.8%. Dissolved inorganic nitrogen forms, NO3-and NH₄+, were constant from April to October, whereas phosphate was depleted in August. Chlorophyll a decreased from 520.0 ± 165.0 to 199.6 ± 159.9 μg.g^-1 dry weight; in contrast, chlorophyll c and carotenoids did not change until September but increased threefold in October. C:N and N:P ratios changed in the same way and in the same range. They were constant until July but increased from 15–17 up to 42 (C:N) and from 14 to 40 (N:P) in October, suggesting a severe P limitation of growth of this species. The dark respiration rate and the light compensation point were constant from April to October (0.5 ± 0.1 μmol O₂. m^-2.s^-1 and 6.5 ± 0.2 μmol.m^-2. s^-1, respectively), whereas the maximum rate of apparent photosynthesis, light onset saturation parameter, and half saturation constant for light were maximum in April to May (3.7 μmol O₂. m^-2.s^-1and 40 and 41.5 μmol.m^-2. s^-1, respectively) and October (3.6 μmol O₂. m^-2.s^-1 and 50 and 53.7 μmol.m^-2. s^-1, respectively). They were minimum in August (1.2 μmol O₂.m^-2.s^-1 and 11.3 and 12 μmol.m^-2.s^-1, respectively). These minimum figures yielded a negative carbon budget in August and 0 in September, whereas it was positive the rest of the year. Photosynthetic efficiency, estimated by the ratio between maximum apparent photosynthesis and light half saturation constant, showed a strong agreement with productivity measured by means of an independent method. These results indicate that lamina expansion in this species is controlled by photosynthetic efficiency.     

光合细菌H3菌株色素分析

H3菌株系由盐田微生物层中分离获得的光合细菌株。具有丰富的天然色素。经活细胞色素光谱吸收峰值测定,色素经有机溶剂提取、硅胶薄板层析、SDS－PAGE电泳等,结果表明H3菌株的主要色素包括细菌叶绿素a、细菌脱镁叶绿素（Bacteriophaeophytin）和三种类胡萝卜素。总胡萝卜素含量占细胞于重的0．6％,胡萝卜素蛋白复合体的分子量约11,000.培养条件的差异对色素形成及相对含量有不同程度的影响。     

SINGLE-CELL PIGMENTATION OF PORPHYRA LINEARIS ANALYZED BY FOURIER TRANSFORM MULTI-PIXEL SPECTROSCOPY AND IMAGE ANALYSIS1

The novel method of Fourier transform multi-pixel spectroscopy was used for the nondestructive analysis of and comparison of pigmentation in different regions of live thalli of the red alga Porphyra linearis. Because the thallus in this alga consists of a monolayer of nonoverlapping cells, we were able to analyze the pigmentation of single cells by combining light absorbance with natural fluorescence data. From the image of each cell in the vegetative male and female reproductive and holdfast regions, more than 4 ± 10⁴ fluorescence and absorbance spectra were obtained. Specific pigments in the different regions were localized by the use of a software program of similarity mapping followed by image construction. The reconstructed images revealed subcellular localization of each pigment according to specific spectroscopic fingerprints. The results showed that the vegetative and female reproductive cell types had a significantly higher content of phycoerythrin than of phycocyanin, and quite similar chlorophyll a levels. Most of the holdfast cells were poorly pigmented, but had more chlorophyll a than phycoerythrin or phycocyanin. The male reproductive cells contained only traces of pigments. Thus, by using Fourier transform multipixel spectroscopy, we were able to characterize the pigmentation of different regions of the thallus and follow the distribution patterns of the different pigments on the subcellular level along the differentiation gradient of the alga.     

HPLC-analysis of algal pigments: comparison of columns,column properties and eluents

The effects of columns (Nucleosil C₁₈ODS, MZ-PAH, YMC-PACK C₃₀), column properties (inner diameters of 4 mm, 3 mm and 2 mm, pore-width 10 nm and 30 nm) and eluents (methanol, acetonitrile, acetone, water) were tested on the separation of algal pigments. The length of columns was 250 mm and particle size was 5 μm. Flow rates and gradients were adjusted to optimize peak separation; remaining chromatographic conditions were kept constant. The resolution of chromatographic systems was tested with pigment standards and various algal cultures. Total flow rate and retention times decreased with decreasing inner diameter, whereas pressure, sensitivity and peak-width increased. Pore width had negligible effects on the chromatographic separation of pigments under the test conditions. Only with acetonitrile as eluent were all the taxonomically important pigments resolved adequately: zeaxanthin (Cyanophyceae), lutein (Chlorophyceae), fucoxanthin (Bacillariopyceae), alloxanthin (Cryptophyceae), peridinin (Dinophyceae).     

Localization of visual pigments within rhabdoms of the compound eye of Spodoptera exempta (Insecta,Noctuidae)

Summary In the noctuid moth Spodoptera exempta, the distribution of visual pigments within the fused rhabdoms of the compound eyes was investigated by electron microscopy. Each ommatidium regularly contains eight receptor cells belonging to three morphological types: one distal, six medial, and one basal cell (Meinecke 1981); four different visual pigments — absorption maxima at approximately 355, 465, 515, and 560 nm — are known to occur within the eye (Langer et al. 1979). The compound eyes were illuminated in situ by use of monochromatic light of different wavelengths. This illumination produced a wide scale of structural changes in the microvilli of the rhabdomeres of individual cells. Preparation of eyes by freeze-substitution revealed the structural changes in the rhabdomeres to be effects of light occurring in vivo.The degree of structural changes may be considerably different in rhabdomeres within the same ommatidium; it was found to depend on the wavelength and the duration of illumination, the intensity received by the ommatidia as well as the spectral sensitivity of the receptor cells. Therefore, it was possible to estimate the spectral sensitivities of the morphological types of receptor cells. Generally, all medial cells are green receptors and all basal cells red receptors; distal cells are blue receptors in about two-thirds of the ommatidia, while in the remaining third of them distal cells are sensitive to ultraviolet light.Supported by Deutsche Forschungsgemeinschaft, Sonderforschungsbereich 114 (Bionach)     

Investigations of the pigments fromCytophaga johnsonae Cy j1

Besides carotenoids a complex of flexirubin-type pigments was isolated from the gliding bacteriumCytophaga johnsonae Cy j1 and separated into 6 components, which partly containe chlorine. In spite of the fact that these components still consist of pigment mixtures, the gross structures of 18 new flexirubin-type pigments could be deduced by spectroscopic and chemical investigations. The results open insights into biosynthesis and structural variety of the flexirubins, the novel non-isoprenoid pigments recently found inFlexibacter elegans.Non-Standard Abbreviations FT Fourier transformation - HPLC high pressure liquid chromatography - M⁺ molecular ion - M/M resolution of mass spectrometer - mu mass units - t _R retention time - TLC thin layer chromatography Part 16: Investigations on metabolites of microorganisms. Part. XV: H. Achenbach, W. Kohl, H. Reichenbach: Die Hauptpigmente vonCytophaga johnsonae. Tetrahedron Lett.1977, 1061. Part XIV: H. Achenbach, J. Witzke: Totalsynthese des Flexirubindimethylethers. Angew. Chem.89, 198 (1977); Angew. Chem. Int. Ed. Engl.16, 191 (1977)     

Photosensory retinal pigments in Halobacterium halobium

In Halobacterium halobium, nicotine is known to block the synthesis of retinal. Cells grown in the presence of nicotine do not show any photophobic response. Addition of retinal₁ or retinal₂ restored the photophobic responses to light-increase in the UV and to light-decrease in the green-yellow part of the spectrum. The action spectra of the two retinal₂-photosystems were red-shifted by 15–20 nm, compared with the corresponding retinal₁ systems. We conclude that each of the two photosystems, PS 370 and PS 565, has its own photosensory pigment with retinal as the chromophoric group.     

Response of yellow birch (Betula alleghaniensis Britton) in acid subsoil to micronutrient additions

Summary Singular additions of Cu, Zn and Mo had little effect on height or diameter of yellow birch growing in acid subsoil. However, dry weight of leaves was increased by Zn and dry weight of stems was increased by both Mo and Zn. In addition, several macronutrient levels in leaves and roots were increased by micronutrients, and Al in roots was decreased (by 50%). Zn was the most effective in causing these favorable changes. Application of Zn is suggested as an alternative or supplement to application of limestone in correcting these problems of yellow birch in acid subsoil.     

机械损伤对9种水生植物叶片的影响

水生植物叶片的功能性状特征与陆生植物有所不同,同时叶脉类型也显著影响叶片的功能性状。本研究选取9种具有不同叶脉类型的水生植物,通过对叶脉进行直接损伤,分析叶片性状（形态、色素含量和叶绿素荧光指标）在叶脉受损后的变化程度与叶脉类型的关系。结果显示：具有平行脉的3种水生植物对叶脉损伤具有较强的耐受性;具羽状脉的4种植物主脉受损后显著抑制叶片生长,而侧脉受损的影响在不同物种间有所不同,具有物种特异性。本研究可为大型湖泊水生植物修复的水生物种筛选提供参考。