In order to study the nature of association of chlorophyll molecules to photosynthetic apparatus and its relationship to photochemical reactions, chloroplasts were treated with chlorophyllase and its effect on the activity of the Hill reaction was investigated. Action of chlorophyllase on photochemical activities of chloroplast fragments was observed in the presence of an organic solvent. NADP photoreduction is more sensitive to the treatment with chlorophyllase than DPIP** photoreduction. The ratio of fluorescence emission intensities at 690 and 730mμ at liquid nitrogen temperature was increased after chlorophyllase treatment. These observations suggest that chlorophyll molecules belonging to the photosystem 1 is more susceptible to the treatment with chlorophyllase than those belonging to the photosystem 2.
Metabolism of hydrocaffeic acid (H-Caf) by Arthrobacter sp. was investigated. H-Caf oxidizing enzyme system was induced by hydro-p-coumaric, hydrocaffeic, hydroferulic acids, but not by hydro-o-coumaric, hydrocinnamic and indole-3-propionic acids. H-Cal was not readily oxidized by the cells cultured in caproate or butyrate media. Therefore, the oxidation of H-Cal may be catalysed by an enzyme system which is different from the system involved in the oxidation of aliphatic fatty acids. H-Caf seems to be metabolized via caffeic acid into protocatechuic acid.
Morphological characteristics of the resting nuclei and chromosomes observed in 115 species of 52 genera of Orchidaceae were summarized, and the following five types of nuclei were found in Orchidaceae. Diffuse type: Characterized by the dark staining chromatins without conspicuous aggregation, and associated with the large chromosomes without any particular heterochromatic segment. Simple chromocenter type: Characterized by the light staining chromatins and some dark staining chromocenters with rough surface, and has no connection with chromosome size; some of the chromosomes of the complement have a gradual heterochromatic segment at the proximal region. Complex chromocenter type: Characterized by many dark staining chromocenters which vary in shape and aggregate into several large chromatin blocks, and associated with either medium or small chromosomes; most of the chromosomes of the complement have several gradual heterochromatic segments at proximal as well as interstitial and distal regions. Rod prochromosome type: Characterized by the smooth-faced rod prochromosomes, and associated with small chromosomes; most of the chromosomes of the complement have a clearly distinguishable heterochromatic rod segment at the proximal region. Round prochromosome type: Characterized by the smooth-faced round prochromosomes, and associated with small chromosomes; most of the chromosomes of the complement have a clearly distinguishable heterochromatic round segment at the proximal region.
To know about the mechanism of interconversion of plastids, electron microscopic observations were made on Cryptomeria leaves which aquire a reddish brown color in winter and recover their green color in coming spring to summer. In normal green leaves, two different kinds of plastids have been observed, viz, the chloroplasts having well organized grana structure in mesophyll cells and those completely lacking grana lamellae in bundle sheath cells. General feature of plastids in reddish brown leaves, may be summarized as follows: (1) The presence of red granules of rhodoxanthin (a carotenoid), and a well developed lamellar system involving grana- and intergrana-lamellae. (2) The plastoglobules, osmiophilic granules in plastids, increase in number and size as compared with the chloroplasts in normal green leaves. (3) Shrinkage which is one of the characteristic features of senescent plastids is not observed. (4) RNA content in plastid stroma is almost unchanged throughout an entire leaf stage ranging from normal green to subsequent regreening. Basic structure of the plastids in regreened leaves is quite similar to that in winter leaves, except for some increase of thylakoid membrane and decrease of osmiophilic granules. Accordingly, it is presumed that the plastids appearing in reddish brown leaves are not mere chromoplasts but those having an incipient nature of the chloroplast, since real chromoplasts can not be converted into the chloroplasts. It seems that “monotrope Plastiden-Metamorphose” is plausible in this case.
A new ectoparasitic, colorless alga is reported here with the taxonomic description of a new genus and a new species as a member of the Cladophorales. This alga grows on shrimps from Japan. All of the vegetative cells are colorless, but the zoosporangia and the zoospores are furnished with many green chloroplasts.
The main reserve carbohydrate extracted with hot water from the tuberous roots of Arrhenatherum elatius var. bulbosum was purified by alcoholic fractionation and charcoal column chromatography and obtained as a single component. This was a hexasaccharide composed of one glucose and five fructose residues. Structural analysis showed that the glucose residue is located at the end of a β-2, 1-linked D-fructofuranose chain in forming the sucrose residue.