Michihiko Yatazawa

Nature of manganese complexes in manganese accumulator plant. Acanthopanax sciadophylloides

Abstract The chemical nature of manganese complexes was investigated in a Mn‐hyperaccumulator plant, Acanthopanax sciadophylloides growing under natural conditions in the forest of central Japan. The concentration of Mn in various cell fractions was in the order: supernatant > cell wall and cell debris > mitochondria > ribosome > chloroplast. Supernatant (105000 x g) was subjected to gel filteration on sephadex G‐10 column. Molecular weight of the major peak of Mn was estimated to be approximately 145 indicating that it was not a protein complex. Mn rich fractions of the major peak were analyzed for organic acids by the use of high performance liquid chromatography. Oxalic acid was the only organic acid detected in these fractions. Paper electrophoresis of the Mn rich fractions of the major peak as well as that of water extracts of the leaves was performed in two ways: 1) paper was treated with pyridineacetic acid buffer (pH 6.5) prior to the application of samples 2) paper was treated with different conc...

Distribution of manganese in leaf tissues of manganese accumulator: Acanthopanax sciadophylloides as revealed by Electronprobe X‐Ray Microanalyzer

Abstract The distribution of Mn in leaf tissues of a Mn accumulator: Acanthopanax sciadophlloides was investigated by means of electron‐probe X‐ray microanalysis using a scanning electron microscope in conduction with a cryostage. Unfixed and frozen plant specimens were used in this experiment. The results show that Mn is densely accumulated in the peripheral cells either of leaf, petiolule and petiole tissues. In the leaf tissues, Mn was highly concentrated in epidermis, palisade and spongy parenchyma cells. Considerable low Mn concentration was observed in vascular bundle cells. Distribution pattern of Mn in petiolule and petiole was similar and characteristic. In petiolule and petiole, most of the Mn was accumulated in the cell wall of epidermis, collenchyma and bundle sheath cells and least was in vascular bundle cells.

ALLANTOIN PRODUCTION AND ITS UTILIZATION IN RELATION TO NODULE FORMATION IN SOYBEANS : Enzymatic Studies

Abstract A remarkable accumulation and utilization of allantoin are observed in soybean plant bearing modules (Glycine max variety A62-1). To study ita physiological role, changes in activities and distribution of the enzymes concerning the purine catabolism (i.e., xanthine oxidase, uricase, allantoinase and allantoicase) were measured during development. Uricase activity was found in the radicles in the early stage of seedling development, and no difference of the enzyme activity was detected between the radicles of the nodulating variety (A62-) and non-nodulating variety (A62-2). On maturation the activity disappeared rapidly in radicles and appeared in leaves, pods and nodules. The activity in nodules was much higher than that in the leaves and the pods throughout the culture period. Xanthine oxidase activity was found in the radicles and nodules. Allantoinase activity was present in all regions of both varieties, and the specific activity in the nodules Was 2-10 times that in other regions. Allantoica...

Microdistribution of aluminum and manganese in the tea leaf tissues as revealed by X‐ray microanalyzer

Abstract Tea plants (Thea sinensis L.) were found to accumulate large amount of Al (4457 ppm, D.W.) in their old leaves. The results showed that Mn stimulated the Al uptake and increased the Al content in the leaves. High concentrations of Ca and Mg in the soils decreased the Al and Mn and increased the Ca and Mg contents in the leaves. No phosphorus and aluminum interaction was found in the leaves of tea plants. Microdistribution patterns of Al and Mn in the tea leaf tissues were also studied by means of a wavelength dispersive type X‐ray microanalyzer in conjunction with cryostage. The results of X‐ray micrographs showed that Al was densely deposited on the cell walls of the adaxial epidermis and palisade parenchyma cells of the old leaf tissues, and this distribution pattern of Al was different than that of Mn which was found mostly concentrated in the epidermal cells.

Nitrogen fixation in Azolla-Anabaena symbiosis as affected by mineral nutrient status.

Abstract The growth and nitrogen-fixing capacity of Azolla imbricata were studied with special reference to the effects of the mineral nutrient status in the medium. The threshold levels of P, K, Mg, and Ca in the medium for Azolla growth were ca. 0.03, 0.4, 0.4, and 0.5 mmol · liter-1, respectively. Full development of nitrogenase activity was not realized at concentrations below 0.03, 0.6, 0.5, and 0.5 mmol · liter-1, respectively. Combined nitrogen was unfavorable for growth and nitrogen fixation. Deficiency of any one of the micronutrient elements, Fe, Mn, Co, Zn, Cu, Mo, and B, had an unfavorable effect on growth and developing nitrogenase activity. The threshold levels of Fe, Mn, Mo, and B for growth were 50, 20, 0.3, and 30 μg · liter-1, and those for nitrogenase activity were 20, 10, 1, and 20 μ · liter-1, respectively. Fe and Mo were very sensitive for developing nitrogenase activity. On the other hand, B was shown to affect growth specifically. The nitrogen-fixing capacity measured from the incr...

Absorption and accumulation of iron, manganese and copper in plants in the temperate forest of central Japan

Abstract Plants (60 species in 37 genera, 27 families) grown on granite weathered soils of temperate natural forest in central Japan were sampled and analyzed for Fe, Mn and Cu. Soil samples coIlceted from the site of plant stands were also analyzed. Results showed that considerable difference existed amons plant species with less variations amons plant samples of the same plant species. Similar responses were frequently found among plant species in the same genus and sometimes in the same family. Variations due to soU also occurred but to a lesser degree. Pe, Mn and Cu were generaIly low in coniferous trees. On the other hand Acantiropanax sciadophylloides accumulated higher amount of Mn in the leaves (4.6 × 103 ppm, dry matter basis) which is about 180 times more than that of low content species. Other Mn accumulating species were found in Anacardiaceae and Aceraceae. Cryptomeria japonica was the lowest in Mn content (26 ppm). Mean concentration ratio for Mn was 113. Cu was found to be slightly rich in ...

Chemical nature of manganese in the leaves of manganese accumulator plants

Abstract The chemical nature of Mn in the leaves of Acanthopanax seiadophylloides, Ilex crenata var. paludosa and Kalopanax pictus was investigated. Successive extraction of freeze-dried and fresh leaf sam pies with various solvents showed that the major portion of Mn (>90%) was extractable with water and 0.2 M HCl. Electron probe X-ray microanalysis was performed with the fresh leaf tissues of Mn hyper accumulator A. seiadophylloides, before and after shaking with distilled water, 80% methanol and 1 M HCl. Water removed large parts of Mn in the tissue as a whole except in the region of the epidermis. A negligible amount of Mn was removed by 80% methanol; on the other hand, 1 M HCl removed almost all of the Mn in the tissues. Paper electrophoretic experiments conducted with water and 0.2 M HCl extracts using pyridine-acetic acid buffer (pH 6.5) indicated that Mn in the extracts behaved similarly to Mn2+, presumably due to the labile nature of Mn components in the tissues.

MANGANESE TOXICITY IN FIELD GROWN TEA PLANTS AND THE MICRODISTRIBUTION OF MANGANESE IN THE LEAF TISSUES AS REVEALED BY ELECTRON PROBE X-RAY MICROGRAPHY

Abstract Tea plants in Toyota district, Aichi Prefecture, which were suspected of Mn toxicity were studied from the viewpoint of the heavy metal interaction and from the microdistribution pattern of Mn in the leaf tissues as revealed by X-ray microanalysis. A high Mn/Fe ratio in the soils was found to be a decisive factor for the disorder in the plants. X-ray micrographs of affected field tea leaves showed that Mn was densely deposited in the epidermis, while no signs of Mn accumulation were observed in the palisade and spongy parenchyma and vascular bundle cells. The Mn distribution pattern in artificially Mn enriched leaves was found to be similar to that of the field grown Mn excess plant leaves. The deposited Mn in the epidermal cells of the artificially Mn enriched leaves was found to move easily when the leaves were dipped in water for 24 hr.

Nitrogen sources for the growth of rice callus tissue

Abstract In the preceding paper (1) the authors described the effect of some conditions on the growth of rice callus tissue. These included the effects of various kinds of sugars, 2, 4-D and yeast extract. In this paper, the availability of different types of nitrogen sources are discussed.

Rhizoplane microorganisms of rice seedlings as examined by scanning electron microscopy

Abstract Rhizoplane microorganisms of water cultured rice seedlings inoculated with soil microorganisms were examined by scanning electron microscopy and optical microscopy. Composition of the bacterial flora on the rhizoplane were also studied. Microorganisms on rhizoplane were limited only in bacteria consisting mostly of rods. They were distributed in every region except the root tip zone. Bacterial aggregations were common at ruptured sites of epidermal cells and cell junctions. They were also dispersed and adhered on mucigel, bare epidermal surface, and root hairs. The area covered with bacteria in the whole root surface was, however, relatively small (1–9%, average 4.6%). Some rhizoplane bacteria were seen to invade into the roots through ruptured sites on epidermis and mucigel. The composition of bacterial flora on rhizoplane was much simpler than that in the paddy soil from which soil inocula were prepared. Pseudomonas and Bacillus occupied about 60 and 40 per cent of the total found in rhizoplane...