Expression of rice OSH1 gene is localized in developing vascular strands and its ectopic expression in transgenic rice causes altered morphology of leaf

Transgenic rice plants (Oryza sativa cv. Nipponbare) carrying 1 or 2 copies of a rice homeobox gene, OSH1, under the control of the CaMV 35S promoter were generated. The transgene caused altered morphology of leaf, such as ligule-replacement and abnormal division of sclerenchyma cells. The phenotype of these leaves resembles that of maize leaf morphological mutant, Knotted 1, which is caused by duplication of the KN1 gene (Veit et al., 1990). The in situ hybridization analysis has revealed that the expression of endogenous OSH1 is mainly localized in developing vascular strands of stem. We have discussed the biological roles of OSH1 in rice based on these results.     

The relationship between amide proton chemical shifts and secondary structure in proteins

Summary The parameters for HN chemical shift calculations of proteins have been determined using data from high-resolution crystal structures of 15 proteins. Employing these chemical shift calculations for HN protons, the observed secondary structure chemical shift trends of HN protons, i.e., upfield shifts on helix formation and downfield shifts on -sheet formation, are discussed. Our calculations suggest that the main reason for the difference in NH chemical shifts in helices and sheets is not an effect from the directly hydrogen-bonded carbonyl, which gives rise to downfield shifts in both cases, but arises from an additional upfield shift predicted in helices and originating in residues i-2 and i-3. The calculations also explain the well-known relationship between amide proton shifts and hydrogen-bond lengths. In addition, the HN chemical shifts of the distorted amphipathic helices of the GCN4 leucine zipper are calculated and used to characterise the solution structure of the helices. By comparing the calculated and experimental shifts, it is shown that in general the agreement is good between residues 15 and 28. The most interesting observation is that in the N-terminal half of the zipper, although both calculated and experimental shifts show clear periodicity, they are no longer in phase. This suggests that for the N-terminal half, in the true average solution structure the period of the helix coil is longer by roughly one residue compared to the NMR structures.     

Effect of low-humidity treatment on growth of the lichenParmotrema tinctorum in a growth cabinet

Low-humidity treatment triggered an increase of the thallus area and the chlorophyll content in the following high-humidity condition. When low-humidity treatment for 4 days was intercalated in high-humidity conditions every 16 days, the thallus area increased 40% in 76 days.     

Pinoid woods with resin canals from the upper cretaceous of Hokkaido and Saghalien

This paper describes six species of permineralized pinoid woods with resin canals from the Upper Cretaceous of Hokkaido, Japan and Saghalien:Piceoxylon transiens Shimakura,P. scleromedullosum Shimakura,P. macroporosum sp. nov.,P. takahashii sp. nov.,Pinuxylon microporosum Ogura andPinoxylon dakotense (Knowlton) Read (new to Saghalien and the Cretaceous).Piceoxylon macroporosum is characterized by large resin canals and rays without ray tracheids and in lacking tylosoids in resin canals.Piceoxylon takahashii, which resemblesP. scleromedullosum, is distinguished from the latter in having ray tracheids and nests of sclereids in pith. Structure and affinities of the petrified plants from the Cretaceous of Northern Japan and Saghalien XVI. (continued from Ohsawaet al. 1995)     

Yezonia,a new section ofAraucaria (Araucariaceae) based on permineralized vegetative and reproductive organs ofA. vulgaris comb. nov. from the upper cretaceous of Hokkaido,Japan

A new specimen of an araucarian cone,Araucaria nihongii, was found attached to the vegetative organs ofYezonia vulgaris, and is described asAraucaria vulgaris comb. nov. Thick branches show characteristic bark structure with lenticular patches. Secondary wood is usually araucarioid. Leaves are arranged helically on shoots, which are imbricate, appressed and fused to surface of the stem. External and anatomical features of leaves closely resembleBrachyphyllum. The seed cone is spherical with winged bracts and thin ovuliferous scales. One seed is borne per cone-scale complex. The seed coat and nucellus wall show typical araucarian structure. An araucarian plant that boreBrachyphyllum-like foliage and aEutacta-like seed cone was predicted by Harris in 1979. This reconstructed plant,Araucaria vulgaris, supports this theory and proves the presence of an extinct characteristic-form of the genus. A new section of the genus was proposed forAraucaria vulgaris. Structure and Affinities of the Petrified Plants from the Cretaceous of Northern Japan and Saghalien XV, Consecutive number from previous paper (Nishidaet al. 1993).     

Dioecy in the endemic genusDendrocacalia (Compositae) on the Bonin (Ogasawara) Islands

Dendrocacalia crepidifolia Nakai (Compositae, Senecioneae), the only species of this arboreal genus endemic to Haha Island in the Bonin Islands, was found to be dioecious. Male flowers differ from female ones in having a stunted style (style in female exserted from corolla and deeply bifurcating) and anthers filled with fertile pollen (anthers in the female lacking pollen). The size of the corolla and number of florets per head were similar between male and female flowers. The crown area of this arboreal species was also similar in male and female plants. The sex ratio was 0.55 male, not significantly different from 0.5. Both sexes produced nectar of similar sugar concentration (ca. 50%). The flowers are pollinated by feral honeybees (Apis mellifera), but they are thought to have been pollinated by small, lesshairy, endemic solitary bees before honeybees were introduced and subsequently became the dominant bee species on the island. The evolution of dioecy ofDendrocacalia on the island is thought to stem from the deleterious effects of inbreeding that are inherent in plants with geitonogamy. The increased geitonogamy on the island has resulted from increased woodiness (i.e., increased number of flowers per plant) and the original dependence on endemic bee pollinators, which are now endangered.     

Cultivation of the lichenParmotrema tinctorum in growth cabinets

The growth of lichens in the field is slow and their cultivation is generally thought to be difficult. We studied the effects of environmental conditions and culture solutions on the growth of a lichen, and found that growth ofParmotrema tinctorum (Nyl.) Hale in growth cabinets was possible. The thallus area increased by about 20% monthly when the lichen was soaked in a culture solution for 90 min every four days and then grown at 100% relative humidity when the temperature in the growth cabinet was 20C and illumination was at 12 W/m² for 16 hr daily.     

High-performance liquid chromatography of apolipoproteins in serum high-density lipoproteins

A simple and rapid method for apolipoprotein analysis in serum high-density lipoproteins (HDL) has been developed using high-performance liquid chromatography (HPLC) with sodium phosphate buffer (pH 7.0) containing 0.1% sodium dodecyl sulphate (SDS) as eluent. In contrast to the use of urea solution as an eluent, apolipoproteins can be analysed by applying an incubation mixure of HDL and the eluent buffer. A TSK-GEL column of G3000SW was found to be more profitable than G2000SW or G4000SW for analysis of HDL apolipoproteins. Elution patterns monitored by absorbance at 280 nm using a G3000SW column can give precise quantitative as well as qualitative information about apolipoproteins of molecular weight between 10⁴ and 10⁵. HPLC patterns of HDL apolipoproteins were compared between individual human subjects with various diseases. Elution profiles for lipid components in an incubation mixture were also examined.     

Cellular and subcellular distribution of iron in the lamina propria of rat duodenum

Summary Cellular and subcellular distribution of iron in the lamina propria of rat duodenum was studied after a single i.p. injection of iron dextran, using electron microscopy and peroxidase cytochemistry. X-ray spectrum microanalysis was used for positive identification of iron. Ironcontaining particles (IP) were found in the cytoplasm of three cell types, viz. macrophages, pericytic reticular cells and sheathing fibrocytes. IP-containing organelles in lamina propria cells were more heterogeneous compared to absorptive cells and, in addition, some differences were noted in the subcellular distribution of IP in the 3 cell types. A common denominator in these 3 cell types was the presence of endogenous peroxidase, also shared by Kupffer cells which are known to be involved in iron storage. Peroxidase activity was absent in absorptive epithelial cells. It is hypothesized that the cells of the lamina propria, like Kupffer cells, may be the site of storage of excess iron absorbed, releasing iron upon demand and migrating into the lumen to prevent iron overload. In this fashion they may regulate the exchange of iron with the environment. The presence of peroxidase in these as well as Kupffer cells, and its absence in absorptive cells also raises the possibility that this enzyme may be related to certain aspects of iron storing process.