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Volume 41 (1975)
- Issue 5 Pages 423-
- Issue 4 Pages 337-
- Issue 3 Pages 233-
- Issue 2 Pages 131-
- Issue 1 Pages 1-
Volume 41, Issue 4
Displaying 1-15 of 15 articles from this issue
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Difference in protease activity of X. oryzae isolatesHiroshi FUJII, Tsutomu UEMATSU1975 Volume 41 Issue 4 Pages 337-344
Published: October 25, 1975
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSProtease activity of various X. oryzae isolates including N7301 mutant clones and several wild types was investigated in relation with their virulence. Activity was assayed by halo-colony (H-C) ratio method on casein media, and also by ordinary Casein-Lowry method on crude enzyme solution obtained from culture filtrate.
It was found that X. oryzae showed marked protease activity. The protease activity in crude enzyme solution was enhanced along with bacterial multiplication, and decreased after stationary stage of bacterial growth. The activity was stable at pH ranging from 6 to 9, optimum at pH 9.3, and seemed an alkaline protease. Several other properties of the enzyme were also investigated.
Among wild-type isolates of X. oryzae, H-C ratio was considerably correlated with the virulence. Virulent isolates showed higher H-C ratio than less virulent ones, and also halos of virulent isolates were much clearer. Among N7301 mutant clones, however, the correlationship was not distinct. According to Casein-Lowry method, no close relationship was found between protease activity and bacterial virulence.View full abstractDownload PDF (714K) -
II. Inhibition of Virion-Associated RNA TranscriptaseMasanobu NAKATA, Naoji SUZUKI1975 Volume 41 Issue 4 Pages 345-355
Published: October 25, 1975
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSFor the purpose of screening some antiviral agents which do not affect the function of cell DNA but inhibit the viral RNA synthesis, the in vitro systems for assaying RDV-RNA transcriptase and E. coil DNA-dependent RNA polymerase were employed and several dyes and drugs were tested for their inhibitory effects on both enzyme activities in darkness and under illumination. Acridine orange, ethidium bromide, methylene blue, azure B, azure A, azure C and thionine inhibit both E. coli DNA transcription and RDV-RNA transcription at P/D ratios (molecular ratios of P in RDV-RNA to dye) of 10/2 and 10/4 to almost the same extents, 40 to 70%, whereas chloroquine, quinacrine, luteoskyrin, actinomycin D and rifamycin SV inhibit only E. coli DNA transcription but do not RDV-RNA transcription. Since some of the dyes belonging to the first group have been known to catalyze the photodynamic reaction of DNA and RNA, azure B was tested for its catalytic effect on the same reaction of RDV-RNA. Actually, azure B inhibits RDV-RNA transcription by about 50% at a P/D ratio as low as 10/0.06 when the reaction mixture is illuminated at 20, 000lux. When RDV-RNA is illuminated in the presence of azure B, only guanine is lost at P/D ratios above 10/0.12. When RDV virions are pretreated with azure B under illumination and then added to the reaction mixture, 50% inhibition of RDV-RNA transcription occurs after 30min. illumination at P/D ratio of 10/0.015. When 32P-labeled RDV virions are illuminated in the presence of azure B and RNA is extracted by phenol method, loss of guanine in the extracted RNA can not be detected but the yields of RNA are decreased, conversely 32P bound to protein is increased with the increasing dose of azure B. From these results it is concluded that the inhibition caused by azure B in darkness is due to the intercalation of dye into the double-stranded RNA, but the inhibition occurring under illumination is due to the photodynamic reaction catalyzed by the dye and is much more effective than that occurring in darkness. Since plants are exposed to sunlight during the daytime, the latter mechanism may predominate in the azure B-treated RDV-infected rice plants.View full abstractDownload PDF (1216K) -
Hiroyuki IEKI1975 Volume 41 Issue 4 Pages 356-363
Published: October 25, 1975
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSThe ultrastructure of root of mulberry trees infected with violet root rot fungus (Helicobasidium mompa Tanaka) was observed.
Infection cushion of this fungus was formed on roots, and the penetration into young root tissues occurred through the cell suture of cork layer of root. As soon as hyphae reached the cortex, each hypha elongated in all direction invading cortex cells. Abundant hyphae were observed in the cortex surrounding the xylem and caused severe degeneration of cortex cells. Some of the hyphae elongated into vessels through a pit. The cellulose microfibrils of cell wall of the invaded cells were irregularly arranged, showing the degeneration pattern. The nucleoplasm appeared granular. The plasmolysis occured in all the invaded cells and plasma membrane was cut into small pieces. The degeneration of pectic substances present in the middle lamella resulted in the intercellular spaces.
The hyphal cells of infection cushion were irregular in shape. Those in the mergin of infection cushion were larger, if compared with those of the central part of infection cushion. Finely granular substances, generally called cementing material, appeared to fill the spaces between the adjoining hyphae. The hyphal cells were rich in glycogenlike granules and organelles. A single pore was observed in a hyphal septum. Woronin body enveloped by a unit membrane was present near the septal pore.View full abstractDownload PDF (2552K) -
I. Relationship between the increase in respiratory rate and multiplication of the bacteria in the infected leavesMinoru WATANABE, Takao ASAUMI1975 Volume 41 Issue 4 Pages 364-372
Published: October 25, 1975
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSThe relationship between the increase of bacteria and the changes in respiratory rate of rice leaves infected by Xanthomonas oryzae was examined.
In the susceptible leaves, the bacteria multiplied rapidly, and reached to 106∼107 cells, when lesion appeared 7 to 14 days after inoculation. Oxygen uptake increased markedly after the first appearance of the symptom, and showed a value 1.7 times as high compared with that of healthy tissues. A high correlation between the number of bacteria and the degree of oxygen uptake was found.
While, in the resistant tissues, the bacteria multiplied gradually to 105∼106 cells, then stopped their increasing, without any visible lesion. A rapid increase in oxygen uptake during the earlier phases of infection was not observed, and the increase at the later phases was limited only 1.3 times compared with that of healthy tissues. On the other hand, in the rice leaves inoculated with the incompatible bacterium X. phaseoli, neither the disease occurrence nor the increase in oxygen uptake was observed.
The investigation with leaf pieces variously distant from inoculated point proved that both the number of bacteria and the rate of respiratory enhancement decreased proportionally with the distance.
It was presumed that the enhanced uptake of oxygen was essentially a host response to the pathogen rather than a reflection of pathogen respiration.View full abstractDownload PDF (1699K) -
Kiyoshi KIRIYAMA1975 Volume 41 Issue 4 Pages 373-377
Published: October 25, 1975
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSTobacco stunt disease (TSD) antigen was partially purified by differential centrifugation from infected tobacco leaves showing typical symptoms of TSD. The partial purified preparation was mixed with equal volume of Freund's complete adjuvant, and was injected three times to mice weekly followed by tumor injection. Ascitic fluids in immunized mice contained both TSD antibody and healthy tobacco antibody. The ascitic fluid absorbed with healthy tobacco antigen react with TSD antigen only. Mouse antibody against Hatano isolate of TSD formed a precipitin line between the antigen of Iwate isolate as same as Hatano isolate of TSD by agar diffusion test. It was shown that serodiagnosis of naturally infected TSD can be used by agar diffusion tests using absorbed mouse ascite.View full abstractDownload PDF (1311K) -
Kazuo SUZUKI1975 Volume 41 Issue 4 Pages 378-382
Published: October 25, 1975
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSThe alteration of sugar level responsible for the development of a poplar leaf rust, caused by Melampsora larici-populina Kleb., was investigated.
In diseased leaves, before visible symptoms appeared, sugar alterations occurred rapidly upon infection. Total content of sugar and sugar alcohol in the diseased leaves increased after inoculation. The amount of arabitol in rusted leaves differed remarkably and this may be attributable to the presence of mycelium in the tissue, though the possibility that arabitol occurs in the host cannot be excluded.
The most interesting result was observed in the correlation between the content of sucrose and an unknown substance. The lower level of sucrose was reached at an earlier stage of infection, when the maximum concentration of the unknown substance was detected.View full abstractDownload PDF (526K) -
Yuichi HONDA, Toshifumi YUNOKI1975 Volume 41 Issue 4 Pages 383-389
Published: October 25, 1975
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSIn order to determine the effective spectral region for stimulating maturation of apothecia of Sclerotinia trifoliorum Erik., sclerotia embedded in sterilized soil were irradiated through coloured cellophane films in a green house under natural conditions or irradiated continuously by fluorescent lamps with glass filters. Radiation filtered throught colourless, blue, green or yellow cellophane films was effective in stimulating maturation of apothecia, while the radiation filtered through red cellophane was not. On the other hand, in the experiment with coloured fluorescent lamps not only red but also green and yellow lamps had no stimulative effect on maturation of apothecia. Studies with glass filters which cut off all radiations shorter than the wavelength designated for each filter indicated that near-ultraviolet radiation between 300 and 390nm stimulated apothecial maturation, whereas wavelengths longer than 390nm were not effective. From these results it can be concluded that the sporulation response to light of this fungus is similar to that of the fungus sensitive to near-ultraviolet radiation, and the effective radiation under green and yellow cellophane is due to transmission bands in near ultraviolet region.View full abstractDownload PDF (713K) -
Hiroshi TOCHIHARA, Takashi IDEI, Shun-ichi YABUKI, Fumiyoshi FUKUMOTO1975 Volume 41 Issue 4 Pages 390-399
Published: October 25, 1975
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSA survey of viruses infecting carnation was made on 116 commercially grown carnation plants (28 cultivars) collected in Japan between 1969 and 1972. Carnation mottle virus (CaMoV), carnation latent virus (CaLV) and carnation vein mottle virus (CaVMV) were found in 66 out of 116, in 51 out of 93 and in 48 out of 105 samples tested, respectively. Carnation etched ring virus and carnation necrotic fleck virus were also found in many of the samples. The survey indicated that these five viruses are the major viral pathogens of carnation in Japan.
CaMoV, CaLV and CaVMV were purified and their particle morphology was examined by electron microscope. Specific antisera to these viruses were obtained using the purified preparations. The host range and the symptomatology were studied by mechanically inoculating these viruses to test plants.
Silene pendula reacted to CaVMV with the formation of distinct necrotic spots in inoculated leaves followed by the appearance of chlorotic and/or necrotic spots in systemically infected leaves. These symptoms were also accompanied by dwarfing. S. pendula was more sensitive to CaVMV than any other indicator plant, and its reaction to this virus was usually sufficiently distinct from the reaction to other carnation viruses.
Cuttings of virus-free clonal plants of cultivar “coral” were inoculated with purified CaMoV. In spite of an active virus multiplication in inoculated tissues, few, if any virus was detected in newly developed leaves for a few months, when the plants were inoculated with low concentration of virus or when they were inoculated at an apical portion. However, the number of plants with low virus concentration was smaller in the artificially inoculated plants than in the plants grown in the field.View full abstractDownload PDF (2550K) -
Yasushi TAKAGI1975 Volume 41 Issue 4 Pages 400-404
Published: October 25, 1975
Released on J-STAGE: February 19, 2009
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Hiroyuki IEKI1975 Volume 41 Issue 4 Pages 405-407
Published: October 25, 1975
Released on J-STAGE: February 19, 2009
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Islam Din KHAN, Keisuke KOHMOTO, Syoyo NISHIMURA1975 Volume 41 Issue 4 Pages 408-411
Published: October 25, 1975
Released on J-STAGE: February 19, 2009
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Akitoshi TAJIMI1975 Volume 41 Issue 4 Pages 412-414
Published: October 25, 1975
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSOrchardgrass clonal lines were used to maintain not only stem rust of orchardgrass, but also stem rust of timothy or ryegrass. The differentiation of three formae speciales were successful with some of these clonal lines. These facts indicate that three rusts are closely related each other.View full abstractDownload PDF (779K) -
Haruo MIURA, Hiroshi ITO, Shozi TAKAHASHI1975 Volume 41 Issue 4 Pages 415-417
Published: October 25, 1975
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSThe diminishing effect of an antibiotic, Kasugamycin, on rice blast fungus has been a serious problem since 1971 in Shonai district, Yamagata Prefecture. Most isolates of the fungus from this district showed resistance to this antibiotic in plate and field tests. Such endemic occurrence could be related to the exclusive and frequent usage of this antibiotic for these several years in this district.View full abstractDownload PDF (289K) -
Kohei TOMIYAMA, Masahiro FUKAYA1975 Volume 41 Issue 4 Pages 418-420
Published: October 25, 1975
Released on J-STAGE: February 19, 2009
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1975 Volume 41 Issue 4 Pages 422
Published: 1975
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSDownload PDF (30K)
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