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1.
The Association of Ascorbate and Ascorbate Oxidase in the Apoplast with IAA-Enhanced Elongation of Epicotyls from Vigna angularis 总被引:1,自引:0,他引:1
The level of (ascorbic acid (AA) plus dehydroascorbic acid (DHA))and the ratio of the level of AA to that of AA plus DHA in intercellularwashing fluid (IWF) of epicotyl segments from Vigna angularisdecreased from 2.8±0.3 to 1.2±0.5nmol (g fr wt)1and from 0.23±0.03 to 0.13±0.01, respectively,after incubation of the segments without IAA for 20 h at 27°C.However, these values changed to 5.3±1.7 nmol (g fr wt)1and 0.07±0.05 after incubation with 0.1 mM IAA. The activityof cell wall-bound ascorbate oxidase increased by about 20%and 70% after incubation without IAA and with IAA, respectively.However, the activity of cell wall-bound peroxidase was notaffected by incubation with or without IAA. The activities ofascorbate oxidase and peroxidase in IWF decreased by about 85and 75% after incubation without IAA. IAA did not affect thesedecreases to any great extent. A lignin-like compound was formedduring the incubation of epicotyl segments in the absence ofIAA. Formation of this compound was inhibited by IAA. The resultssuggest that one of the causes of the enhancement of elongationgrowth by IAA is the inhibition of peroxidase-dependent lignificationas a result of increases in levels of AA and DHA and in ascorbateoxidase activity. (Received August 16, 1993; Accepted December 6, 1993) 相似文献
2.
Monoclonal antibodies against chick embryonic beta-galactoside-binding lectin were obtained. One of the monoclonal antibodies was ineffective in Western blotting and seemed to be unable to bind the SDS-denatured lectin. When the native lectin was dotted on a nitrocellulose filter and subjected to denaturation by treatment with SDS, urea or heat, binding of this antibody no longer occurred, though other monoclonal antibodies bound normally. This antibody seems to have been raised against an epitope which is destroyed upon denaturation. 相似文献
3.
The alteration of hepatic drug-metabolizing enzyme activities in mice given Salmonella endotoxin by single or multiple intraperitoneal injections was investigated. An essentially the same biphasic, early and late phase, endotoxin tolerance was observed in the animals receiving a single injection of endotoxin or repetitive daily injections. The results of reciprocal cross tolerance tests using lipopolysaccharide and free lipid A preparations derived from Salmonella minnesota, Salmonella typhimurium, E. coli, Pseudomonas aeruginosa, and Chromobacterium violaceum suggested that lipid A moiety plays an important role in the induction of early endotoxin tolerance to endotoxin response. 相似文献
4.
Ogawa Masahiro; Kumamaru Toshihiro; Satoh Hikaru; Iwata Nobuo; Omura Takeshi; Kasai Zenzaburo; Tanaka Kunisuke 《Plant & cell physiology》1987,28(8):1517-1527
Protein body type one (PB-I) was isolated and purified fromdeveloping rice grain by a combination of sucrose density gradientcentrifugation and treatment with pepsin. SDS-PAGE analysisshowed that isolated PB-I contains several polypeptide groups,the largest having an apparent molecular size of 13 kDa andtwo smaller ones of 10 kDa and 16 kDa. The 13-kDa group wasfound to be composed of two polypeptides of slightly differentmolecular sizes, 13a (larger component) and 13b (smaller component).Most of the 13a and 13b polypeptides were shown to be largelyprolamins, although there were also some salt- and alcohol-insolublepolypeptides with an apparent molecular size of 13 kDa. It wasconcluded that PB-I is the accumulation site of rice prolamin.It was further estimated that the protein amount in PB-I accountedfor about 20% of the total protein of rice endosperm. (Received March 20, 1987; Accepted September 8, 1987) 相似文献
5.
Auxin induced growth and decreased the hexosamine content ofthe cell walls of rice coleoptile sections. Indole-3-aceticacid (IAA) at 105 M inhibited the incorporation of 14C-glucosamineinto the cell walls. IAA did not affect the 14C-incorporationinto the cytoplasm, while inhibitors of glycoprotein synthesis,unicamycin and monensin, suppressed the incorporation into boththe cytoplasm and the cell walls. The radioactivity due to labeledglucosamine in the cell walls increased during the chase, butthis increase was inhibited by IAA. Among the cell wall fractions,the increase in radioactivity and its inhibition by IAA wereconspicuous in the hemicellulose I fraction. The inhibitoryeffect of IAA on glucosamine incorporation into the cell wallswas observed even in the presence of 0.15 M mannitol solutionwhich completely suppressed the IAA-induced growth. These resultssuggest that auxin induces growth at least partly by inhibitingthe transport of asparagine-linked glycoproteins from the cytoplasmto the cell walls.
1 Present address: Department of Biology, Faculty of Science,Osaka City University, Sumiyoshi-ku, Osaka 558, Japan (Received July 23, 1986; Accepted December 22, 1986) 相似文献
6.
Optimum conditions for electric pulse-mediated gene transfer to mammalian cells in suspension 总被引:5,自引:0,他引:5
H Hama-Inaba M Takahashi M Kasai T Shiomi A Ito F Hanaoka K Sato 《Cell structure and function》1987,12(2):173-180
A pulse-generating machine which delivers exponentially decaying pulses over broad range of pulse lengths was used to determine the optimum pulse conditions for gene transfer to FM3A cells. In the transformation of tk- cells with pTK1, a single pulse of 100-2000 microseconds gave a high transformation frequency at 1.5-6 kV/cm and room temperature, the highest transformation frequency obtained being 3 X 10(-3). As the suspension buffer for cells exposed to the pulse, Saline G was better than PBS(-) for obtaining a large number of transformants because it ensured high cell viability. 相似文献
7.
8.
Yuichi Fujita Yasuhiro Takahashi Takayuki Kohchi Haruo Ozeki Kanji Ohyama Hiroshi Matsubara 《Plant molecular biology》1989,13(5):551-561
The frxC gene, one of the unidentified open reading frames present in liverwort chloroplast DNA, shows significant homology with the nifH genes coding for the Fe protein, a component of the nitrogenase complex (Ohyama et al., 1986, Nature 322: 572–574). A truncated form of the frxC gene was designed to be over-expressed in Escherichia coli and an antibody against this protein was prepared using the purified product as an antigen. This antibody reacted with a protein in the soluble fraction of liverwort chloroplasts, which had an apparent molecular weight of 31 000, as revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, in good agreement with a putative molecular weight of 31945 deduced from the DNA sequence of the frxC gene. In a competitive inhibition experiment, the antigenicity of this protein was indicated to be similar to that of the over-expressed protein in E. coli. Therefore, we concluded that the frxC gene was expressed in liverwort chloroplasts and that its product existed in a soluble form. The molecular weight of the frxC protein was approximately 67 000, as estimated by gel filtration chromatography, indicating that the frxC protein may exist as a dimer of two identical polypeptides analogous to the Fe protein of nitrogenase. The results obtained from affinity chromatography supported the possibility that the frxC protein, which possesses a ATP-binding sequence in its N-terminal region that is conserved among various other ATP-binding proteins, has the ability to bind ATP. 相似文献
9.
10.
We produced a computer program that draws pedigree charts for inbred strains of animals such as mice or rats. This program is composed of four subprograms, which are (1) inputting the data, (2) drawing pedigree charts, (3) listing the data which have been input, and (4) backup of the system and the data. Pedigree charts and lists of data can be displayed on a TV screen and printed out on the papers. Using this program, we drew the pedigree charts of the inbred strains of rats which we are maintaining by brother-sister inbreeding in our institute and found that there were three sublines in one of the strains, WKAH/Hkm, because of unsuitable maintenance. This program is very convenient to draw the pedigree charts and useful for checking the maintenance of inbred strains or the strains of animal models of human diseases. 相似文献