Turnover of cell wall polysaccharides of a Vinca rosea suspension culture

Three-day-cultured cells of Vinca rosea L. (in the cell division phase) and 5-day-cultured cells (in the cell expansion phase) prelabelled with d -[U-¹⁴C] glucose were incubated in a medium containing unlabelled glucose. After various periods of chase, extra-cellular polysaccharides (ECP) and cell walls were isolated, and cell walls were fractionated into pectic substances, hemicellulose, and cellulose fractions. After acid hydrolysis, the radioactive constituents in the pectic substances and hemicellulose fractions were analyzed. Active turnover was observed in arabinose and galactose in the hemicellulose fraction of cell walls, while the constituents of the pectic substances, and xylose and glucose in the hemicellulose fraction did not undergo active turnover. The proportion of radioactivities of arabinose and galactose in total radioactivity of ECP increased markedly after chasing. These results indicate that arabinogalactan was synthesized, deposited in the cell wall, degraded rapidly, and made soluble in the medium as a part of ECP.     

IMMUNOCHEMICAL STUDY ON THE SPECIES SPECIFICITY OF SPERM-BINDING PROTEIN FROM THE SURFACE OF THE SEA URCHIN EGG*

Immunological species specificity of sperm-binding protein from eggs of the 4 sea urchin species, Hemicentrotus pulcherrimus, Pseudocentrotus depressus, Anthocidaris crassispina and Temnopleurus toreumaticus, was examined by means of double immuno-diffusion technique in agar. Ca-soluble fraction of sperm-binding protein which is considered to be responsible for initial sperm-egg bonding at fertilization, has species-specific antigenic component. Correlations in antigenic constituents among the 4 species are described.     

Minor carotenoid components in the chloroplasts of higher plants

One-dimensional thin layer chromatography with microcrystallinecellulose was used for the separation of minor carotenoid componentsin spinach, parsley and Brassicachloroplasts. It was revealedthat chloroplasts of these plants contain two minor xanthophyllcomponents besides carotenes, lutein, violaxanthin and neoxanthin.These minor components, designated as xanthophyll–443and –439, were different in spectral properties from antheraxanthinand zeaxanthin which are known to be present in the chloroplastsof some higher plants, and evidence was obtained showing thatxanthophyll–439 has an epoxy group. Spectral propertiesof these xanthophylls in benzene, ethanol, H-hexane and carbondisulfide, as well as their contents relative to other carotenoids,are presented in this paper. ¹Postal address     

Isotachophoretic Analysis of Ions in Guard Cells of Vicia faba

Isotachophoretic analysis of ions was performed on guard cells of Vicia faba cv. Ryosai Issun with either open or closed stomata. In guard cells of open stomata, K⁺ and malic acid concentrations were 5–7 and 5–10 times higher, respectively, than in guard cells of closed stomata. The content of citric acid (plus isocitric acid) also increased during stomatal opening, but the increment was smaller than that of malic acid. Sodium ions, phosphoric and glyceric acids were present in low concentrations but did not increase during the opening. Other cations and anions could not be measured because of low concentrations. Malic acid provided 68–79% of the counter anions for the potassium taken up by guard cells during stomatal opening.     

Intraspecific competition as a selective pressure on the choice of oviposition site in a phytophagous insect

Our aim was to clarify the factors providing selective pressures on the choice of oviposition sites in phytophagous insects. To this end, we examined the spatial distribution of eggs of the sawfly leaf miner, Profenusa japonica . The study was conducted over five consecutive years on three subpopulations found in riverbeds in central Japan. Profenusa japonica lays eggs on leaflets of Rosa multiflora , and its larvae mine a single leaflet for the entire larval stage. The egg distribution among leaflets was uniform (regular) at all sites examined in each year. The distribution within leaflets was also uniform, and it appeared that females avoided ovipositing on areas of the leaf that already contained eggs. Few parasitoids were found in eggs or larval stages, despite intensive examination. Larval mortality increased, mainly as a result of exploitative competition, when there were two or three larvae per leaflet. Starvation caused by resource competition for leaflet tissues was an important mortality factor. Therefore, we suggest that P. japonica females avoided ovipositing on areas of the leaflet that already contained eggs to prevent exploitative competition among larvae sharing the same leaflet.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 92 , 641–650.     

Possible Roles of Methyl Glucoside andMyo-inositol in the Opening of Cut Rose Flowers

Methyl glucoside andmyo-inositol are present in all organs ofrose (Rosa hybridaL.). To investigate the possible role of thesecarbohydrates in the opening of cut roses, flowers with a 10,20 or 40-cm-long stem and a single flower bud (about 1.5 cmin diameter) were placed in water and flower opening and changesin sugar content in flowers and stems examined for 7 d. Thelonger the stem of the cut flower, the larger was the flowerdiameter. In stems, the concentration of carbohydrates, includingmethyl glucoside andmyo-inositol markedly decreased before floweropening. In petals, contents of glucose, methyl glucoside andmyo-inositolalso decreased before flower opening, but those of fructose,sucrose and xylose did not. When glucose and methyl glucosidewere added to the vase water (4%) flower opening was clearlypromoted; this was accompanied by an increase in methyl glucosideand fructose concentrations in petals. On the contrary,myo-inositolinhibited flower opening, and this was accompanied by an increaseinmyo-inositol and xylose concentrations in petals. These resultssuggest that methyl glucoside and/or its metabolites are transportedinto the petal cells, thereby lowering the osmotic water potentialand promoting flower opening.Myo-inositol is not readily metabolized,and exogenousmyo-inositol given at a high concentration mayact as an extracellular osmolyte, which inhibits water uptakeand flower opening.Copyright 1999 Annals of Botany Company Cut flowers, methyl glucoside,myo-inositol,Rosa hybrida,soluble carbohydrate.     

Diversity of pselaphine beetles (Coleoptera: Staphylinidae: Pselaphinae) in eastern Thailand

Pselaphine beetles (Coleoptera: Staphylinidae: Pselaphinae) are cosmopolitan, species‐rich, and yet poorly studied, particularly in the tropics. We sampled beetles in three types of primary forest and two types of disturbed forest habitats in eastern Thailand to assess the utility of pselaphine beetles as bioindicators of forest disturbance. We simultaneously measured leaf litter mass, soil moisture, soil acidity and canopy cover at each site to infer which environmental factors affect pselaphine beetle diversity and abundance. At each site, pselaphine beetles were extracted from ten 1 m² samples of leaf litter and soil with Tullgren funnels. We sampled 1867 adult beetles representing six supertribes, 51 genera and 114 morphospecies; 7% of the genera and 92% of the species were undescribed. Forest types differed significantly in species richness, abundance, diversity and evenness. Primary forest had greater numbers of species and individuals, and higher diversity indices (H′). Teak plantation and secondary forest had substantially fewer individuals and species of pselaphine beetles. Species composition differed between primary and degraded forests. Canopy cover, soil moisture, and leaf litter mass positively correlated with beetle species richness and abundance. Leaf litter mass and soil moisture were the two most important factors affecting the diversity of pselaphine beetle assemblages. Among the 114 morphospecies collected, 43 morphospecies were specific to two or three habitats and 64 morphospecies were found only in a single habitat. Thus pselaphine beetles appear to have rather narrow habitat requirements and their presence/absence was correlated with environmental differences. These traits make pselaphine beetles a suitable bioindicator taxon for assessing forest litter diversity and monitoring habitat change.     

Chemical Factors Affecting Palmelloid-Forming Activity of Chloroplatinic Acid on Chlamydomonas eugametos

In order to elucidate the physiological mechanism of palmelloid formation of the unicellular green alga Chlamydomonas eugametos by chloroplatinic acid, the factors causing inhibition of the palmelloid formation were studied in various media. Chloroplatinic acid lost its palmelloid-forming effect in the presence of nitrite ion and amines having a second functional group. Nitrate, potassium, and sodium ions and monofunctional amines were without influence on the effect of chloroplatinic acid. These results indicate that the active form of platinum (IV) may undergo ligand substitution, the resulting complex being unable to cause palmelloid formation.