Hiroshi Takaki

EFFECT OF NITROGEN SOURCES ON THE CHEMICAL COMPONENTS IN YOUNG PLANTS

Abstract Nitrogen nutrition has great influences not only on the yields, but also on the chemical components of the plants. Nitrate nitrogen is generally found to be superior to ammonium nitrogen as the nitrogen source for higher plants (1). As reported in the previous paper (2), young plants of sugar beet grown with the culture solution containing a high level of ammonium nitrogen developed the symptom of ammonia toxicity. To make clear the mechanism of ammonia toxicity, comparative studies on the absorption and the assimilation of ammonium- and nitrate-nitrogen in higher plants at young stages of growth were carried out.

Diversity of indigenous Bradyrhizobium strains isolated from three different Rj-soybean cultivars in terms of randomly amplified polymorphic DNA and intrinsic antibiotic resistance

Abstract Diversity of indigenous Bradyrhizobium strains isolated from three different Rj-genotypes of soybean (Glycine max L. Merrill) cultivars which was investigated based on randomly amplified polymorphic DNA (RAPD) fingerprinting, intrinsic antibiotic resistance (JAR) and indole-3-aceticacid (IAA) production, was correlated with preference for and compatibility with Rj-genotypes of soybean cultivars for nodulation. Seventeen strains from Akishirome (nonRj), 22 strains from CNS (Rj 2 Rj 3) and 19 strains from Fukuyutaka (Rj 4) were isolated. All of the isolates from Akishirome and Fukuyutaka and 8 isolates from CNS formed effective nodules on each Rj-soybean cultivar, while 14 isolates from CNS did not form effective nodules on Fukuyutaka after inoculation under sterile conditions. The 14 isolates from CNS produced IAA. Cluster analysis based on RAPD fingerprinting using 5 primers revealed the presence of tw.o clusters, A and B. Cluster B contained B. elkanii USDA 61, USDA 76 and indigenous bradyrhizobia of 14 isolates from CNS showing IAA production and cluster A contained B. japonicum USDA 110, AI017 and indigenous bradyrhizobia not showing IAA production. Indigenous bradyrhizobia strains in cluster A were further divided into 3 subclusters, A-I, A-2, and A-3 different from the cluster of B. japonicum USDA 110 and AI017. Identity of subclusters between RAPD fingerprinting and IAR phenotype was not completely obtained. Sub clusters A-I, A-2, and A-3 consisted mainly of isolates from Akishirome, CNS, and Fukuyutaka, respectively. Preferences of bradyrhizobia for Rj-soybean cultivars for nodulation may be estimated by genetic diversity at the strain level.

Distribution of zinc, manganese, copper, cobalt, and nickel in andosols profiles

Abstract The distribution of zinc, manganese, copper, cobalt, and nickel in Andosols was investigated. Sixty nine soil samples were collected from different horizons of an Andosols profile in Miyakonojo Basin in south Kyushu, Japan, The total contents of heavy metals were determined by digestion and four extraction solutions, 1 M NH4Ac (ammonium acetate) pH 4.5, 0.1 M HCl, 0.01 M EDTA (ethylenediaminetetraacetic acid) pH 6.5, and 0.005 M DTPA (diethylenetri-aminepentaacetic acid) pH 7.3 were used to determine the contents of available Zn, Mn, Cu, Co, and Ni in Andosols in relation to the organic carbon content. The results of the extraction analysis showed that by the use of 0.1 M H Cl high value of extracted heavy metals in the upper layers of the humus horizons were obtained while EDTA extraction yielded a large amount of the above mentioned metals in the high humus horizons. The extractable heavy metals contents were high and these metals closely related to the organic carbon content mostly in the humu...

Occurrence of glucosamine in higher plants

Abstract Occurrence of the unknown basic ninhydrin positive substance in young plant tissue supplied with a high level of ammonium nitrogen has been reported in the previous paper (1). This substance disappeared when the supply of ammonium nitrogen was stopped or the source of nitrogen was changed from ammonium nitrogen to nitrace nitrogen, and this substance was verg scarcely detected when the level of ammonium nitrogen in culture solution was as low as 3 ppm or the foren of nitrogen source was nitrace nitrogen. It is very interesting to identify this substance, as the occurrence of this substance is a distinctive character of the plant which han been supplied with a higher level of ammonium nitrogen and has developed the symptoms of ammonia toxicity.

Free-tryptophan and indoleacetic acid in zinc-deficient radish shoots

Abstract Free-tryptophan was detected In higher amounts in zinc-deficient radish shoots than in the control shoots with the use of HPLC. Two-dimensional TLC and GC-MS analysis revealed the presence of IAA in zinc-deficient radish shoots. Quantitative estimation of IAA by gas chromatography showed that zinc-deficient and control radish shoots contained 0.32 and 0.36 μg/100 g f.w., respectively. It could be deduced from these results that zinc nutrition did not affect significantly the amount of IAA in radish shoots.

Zinc nutrition and levels of endogenous lndole‐3‐acetic acid in radish shoots

Abstract Radish (Raphanus sativus cv. Akamaru‐Hatsukadaikon) was grown for several experiments in a glasshouse with zinc (Zn) supply in the nutrient solution. Lack of Zn resulted in stunted growth and reduced leaf of radish shoots were observed. Two‐dimensional thin layer chromatography (TLC) and gas chromatography‐mass spectrometry (GC‐MS) analysis revealed the presence of endogenous indole‐3‐acetic acid (IAA) in Zn‐deficient radish shoots. An estimate has been made of alkali‐labile (1 and 7N NaOH) IAA in Zn‐deficient radish shoots with the use of gas chromatography (GC). The level of 7N NaOH‐labile IAA (peptidic + ester + free) and IN NaOH‐labile IAA (ester + free) in Zn‐deficient radish shoots was almost the same as that of control radish shoots. These results suggest that Zn nutrition did not affect the level of endogenous IAA in radish shoots.

Tryptamine in Zinc-Deficient Barley

Several Ehrlich-positive spots were detected on the thin layer chromatogram (TLC) of the zinc-deficient barley extract developed with n-butanol : acetic acid: water (4 : 1 : 2) as the solvent. Spot 1, a dominant spot in the basic fraction of the zinc-deficient extract gave the same Rf value as the authentic tryptamine on the TLC. No differences were found in chromogenic reactions such as Ehrlich, Salkowsky and ninhydrin reactions. The UV absorption spectrum of the purified spot 1 coincided completely with that of the authentic tryptamine. The purified spot 1 and the authentic tryptamine were compared by GC-MS. The mass spectra observed were identical within the limits of experimental error. Based on these results, it is concluded that a very large amount of tryptamine is present in zincdeficient barley. Tryptamine content was higher in barley shoots, which developed symptoms of zinc deficiency (16 μg/F.W. g). With an adequate zinc nutrition (Zn 50 ppb), tryptamine was also detected in barley seedlings, bu...

Distinctive Expression of a Zinc-Binding Protein in Rice Callus Grown in Medium with High Zinc Concentration

Abstract We investigated the growth, contents of water-soluble protein and free amino acids of the callus of japonica rice (Oryza sativa L. cv. Nipponbare) cultured in liquid N6 medium containing a high concentration of zinc. Furthermore, we determined the N-terminal amino acid sequence of a Zn-binding protein expressed in large quantities in the callus. The addition of Zn stimulated the growth of the callus and increased the Zn concentration. The callus subjected to the high-Zn treatment (hereafter referred to as CHZn) contained a larger amount of soluble proteins and a smaller amount of free amino acids than the control callus. Zinc-binding proteins were separated by affinity chromatography. The SDS-PAGE pattern of these proteins showed a distinctive protein band of about 29 kDa. Especially, CHZn contained larger quantities of 29 kDa protein than the control callus. Twenty-seven N-terminal amino acids of the protein were sequenced as DYAPMTLTIVNNCPYPVWPGIQANSGH. Results of homology search to the amino acid sequences from the nr-aa database and the dbEST database suggested that this 29 kDa protein may be a novel zinc-binding protein and that the protein may regulate the concentration of free zinc in the cytoplasm of callus cells through its binding to zinc ions.

Indole carboxylic acid in zinc-deficient radish shoots

Abstract van Urk-Salkowskys reactive spots were detected on a two dimensional thin layer chromatogram of the acidic fraction from zinc deficient radish shoots. A yellowish and dominant spot gave the same R f value and color reaction as those of the authentic carboxylic acid (ICA). For further identification of ICA in the zinc-deficient radish shoots, GC-MS was employed. The fraction of the methylated final extract, which appeared as a peak on the gas chromatogram at the same retention time as that of the methylated authentic ICA showed high peaks at 175, 144, and 116 m/e. Mass spectra of the methylated authentic ICA revealed the presence of peaks at 175, 144, and 116 m/e. These results suggest that ICA was present in the zinc deficient radish shoots. The amount of ICA in the zinc deficient and control radish shoots were 32 and 1.4 μg/100 g F.W., respectively.

Distribution of micro elements in an andisol profile in Takatoge, Kagoshima, Japan

Abstract The distribution of micro-elements (Zn, Mn, Cu, Co, and Ni) in an Andisol profile of Takatoge in Osumi Peninsula, Kagoshima, Japan was investigated and the factors that influence their distribution during the Andisol forming process were discussed. The upper part of the soil profile consisted of a new ash layer which was deposited from 1946 to 1995 A.D. and originated from Sakurajima volcano. Thirty soil samples were collected from the soil profile for the determination of total and extractable contents of the micro-elements. Total contents of Zn and Mn were almost uniform, but the distribution of total Cu, Co, and Ni was irregular throughout the profile. The ratio of the content of extractable Zn and Mn to that of the total content was very low. The most of Zn and Mn occurred in a non-extractable form (total minus extractable) which was related to the presence of pyroxenese in the fine sand fraction. The ratio of the amount of extractable Cu, Co, and Ni to that of their total was very high compa...