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.
1) Water soluble proteins from leaves of tobacco (N. tabacum “Bright Consolation”. and corn (Zea mays) were fractionated by Sephadex G-100 column (2.5×40cm). Fraction 1 protein conteined ribulosediphosphate (RuDP) carboxylase (E.C.220.127.116.11) as well as phosphopyruvate (PP) carboxylase (E.C.18.104.22.168). 2) PP carboxylase was rapidly inactivated when incubated at above 25°. On the other hand, RuDP carboxylase was stable and the optimum temperature for the enzyme reaction was located at approximately 40°. 3) RuDP carboxylase activity of tobacco leaf on fresh weight basis, attained its maximum when the leaf elongated approximately 50% of its final length, and decreased rapidly thereafter towards leaf senescence. 4) There was a nearly parallel correlation between enzyme activities of RuDP and PP carboxylases and the content of fraction 1 protein of tobacco and corn leaves. 5) The activity of PP carboxylase of young corn leaf was as lower as that of young tobacco leaf, but PP carboxylase activity in matured leaves of corn was 15 times greater than that of tobacco leaves. The activity of RuDP carboxylase was generally lower in corn leaves, 40-70% to tobacco RuDP carboxylase, when compared with the same growth stages of a leaf.
Some properties of granule-bound starch synthetase from leaves and storage tissues of various higher plants were studied. Their pH optima were found in the range of 8.0-9.0 in most enzyme preparations from the plants. Stimulative effect of K+ on the activity of granule-bound starch synthetase was observed in most enzyme preparations from leaves of the plants, but no effect was observed in most enzyme preparations from storage tissues of the plants. Stimulative effect of Mg++, Ca++ and Mn++ on the activity of granules-bound starch syathetase was observed in most enzyme preparations. ADP-glucose was exclusively utilized as substrate by the enzymes from the leaves of the plants, whereas the enzymes from the storage tissues of several plants utilized both ADP-glucose and UDP-glucose as substrate.
Karyological studies were made on three species of Pteris: P. wallichiana, P. inaequalis var. aequata and P. semipinnata. The somatic chromosome numbers of the first two species were found to be 2n=58, and the third was 2n=116. The somatic chromosome complements of these three species can be morphologically divided into six types (A-F), of which the four types (C-F) can be furthermore divided into two groups. Namely, the chromosomes of these three species can be divided into ten groups and each group consists of six chromosomes except for A type consisting of four chromosomes. From these observations, the primary basic chromosome number can be considered to be b=10, which was found for the first time in the Pteridophyta. The two species which possess chromosomes 2n=58 may originate from hexaploid. That is, these can be considered to be derived from the ancestral hexaploid species (2n=60) eliminating one pair of A type chromosomes. P. semipinnata (2n=116) originates from duplicating the 58 chromosomes, so this species is a dodecaploid.
In the present study, the formation of the protonema and the leafy shoots in Andreaea rupestris var. fauriei were observed. The spore of this variety germinates within the exospore and forms 4-6 cells as in other species of Andreaea, after the exospore ruptures a massive protonema consisting of 8-25 cells is found. From this massive protonema, the filamentous and the thallose protonema are produced. In this study, the details on the protonema structure and the development of the filamentous protonema in Andreaea were observed for the first time. It was ascertained in this variety that the leafy shoot is produced from the missive and the thallose protonemata. Especially, the fact that the leafy shoot is produced from the massive protonema was found also for the first time in Andreaeaceae.