Piricularia Oryzae Research Articles

Anti-microbial glycosides of Euptelea polyandra Sieb. et Zucc. I. Isolation, constitutions and anti-microbial activities of eupteleside A and eupteleoside B

Two new glycosides, named eupteleoside A (I) and eupteleoside B (II), were isolated from the leaves of Euptelea polyandra SIEB. et ZUCC. (Eupteleaceae). I, C46H70O17·2H2O, was shown to be a triterpene saponin which gave upon acid hydrolysis the aglycone eupteleogenin and one mole each of L-rhamnose, L-arabinose, and D-glucose. II, C48H72O18·H2O, was correlated to I establishing that II is a monoacetate of I. I and II showed relatively intense anti-microbial activity against Saccharomyces cerevisiae and Piricularia oryzae, as well as some phytopathogenic fungi. Synergistic effect of I and II is also described.

CELL WALLS OF PIRIGULARIA ORYZAE

Cell walls were prepared from Piricularia oryzae P2. Lytic enzymes were produced when Bacillus circulans WL 12 was grown with P. oryzae cell wall as a sole source of carbon. Mode of lysis of P. oryzae cell walls was compared with the lysis of walls of Aspergillus oryzae and Neurospora crassa. Activities of β-1→3-glucanase, chitinase, and β-1→6-glucanase were demonstrated in the culture filtrate. Modes of lysis of cell walls of P. oryzae P2 by a single and combined action of lytic enzymes were compared. Combination of β-1→3-glucanase and chitinase gave the most rapid and extensive lysis.

Immunization of Rice Plants against Helminthosporium Infection

IMMUNIZATION has only recently attracted serious attention for controlling plant diseases. Following their classical studies on infection of potato tubers by Phytophthora infestans, Muller and Borger1 postulated that “phyto-alexins”, produced by plants in response to infection, were responsible for resistance of plants to avirulent races of pathogens or to non-pathogens. On this basis, attempts have been made to induce resistance in plants to pathogens by pre-inoculation either with avirulent races or with non-pathogens, and success has been reported in a number of cases2–7. Brown spot disease of rice caused by Helminthosporium oryzae is often severe in eastern India. Different rice cultivars are known to produce phytoalexin-like substances in response to infection by three important pathogens, Cochliobolus miyabeanus (perfect form of H. oryzae), Piricularia oryzae and Xanthomonas oryzae8,9. Thus immunization of susceptible cultivars against H. oryzae by pre-inoculation with avirulent races seemed possible. Results of attempts to do this are summarized here.

Studies on a Proteinase of Piricularia oryzae

Journal of PhytopathologyVolume 65, Issue 4 p. 318-324 Studies on a Proteinase of Piricularia oryzae D. Jothianandan, D. Jothianandan University Biochemical Laboratory, Madras 25, IndiaSearch for more papers by this authorE. R. B. Shanmugasundaram, E. R. B. Shanmugasundaram University Biochemical Laboratory, Madras 25, IndiaSearch for more papers by this author D. Jothianandan, D. Jothianandan University Biochemical Laboratory, Madras 25, IndiaSearch for more papers by this authorE. R. B. Shanmugasundaram, E. R. B. Shanmugasundaram University Biochemical Laboratory, Madras 25, IndiaSearch for more papers by this author First published: August 1969 https://doi.org/10.1111/j.1439-0434.1969.tb03073.x With 7 figures AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Volume65, Issue4August 1969Pages 318-324 RelatedInformation

AABOMYCIN A, A NEW ANTIBIOTIC. I

The effects of aabomycin A on Piricularia oryzae, the causative agent of the rice blast disease and on the multiplication of Tobacco Mosaic Virus (TMV) were examined. Aabomycin A exhibited marked inhibition on the whole life cycle of P. oryzae including spore germination, mycelial growth and sporulation. The spore germination was the most influenced. The inhibitory activity of aabomycin A was not decreased in kasugamycin-resistant and blasticidin S-resistant clones. The rice blast disease on rice plants was remarkably suppressed by aabomycin A at a concentration of 20ppm. It showed a protective effect rather than a curative effect, contrary to blasticidin S. No phytotoxicity was observed, even at a concentration of 1, 000ppm. The multiplication of TMV was remarkably inhibited by aabomycin A at a concentration of 1-100mcg/ml and no phytotoxicity was observed even at a concentration of 1, 000mcg/ml.

Aabomycin A, a new antibiotic. II. Biological studies on aabomycin A.

The effects of aabomycin A on Piricularia oryzae, the causative agent of the rice blast disease and on the multiplication of Tobacco Mosaic Virus (TMV) were examined. Aabomycin A exhibited marked inhibition on the whole life cycle of P. oryzae including spore germination, mycelial growth and sporulation. The spore germination was the most influenced. The inhibitory activity of aabomycin A was not decreased in kasugamycin-resistant and blasticidin S-resistant clones. The rice blast disease on rice plants was remarkably suppressed by aabomycin A at a concentration of 20ppm. It showed a protective effect rather than a curative effect, contrary to blasticidin S. No phytotoxicity was observed, even at a concentration of 1, 000ppm. The multiplication of TMV was remarkably inhibited by aabomycin A at a concentration of 1-100mcg/ml and no phytotoxicity was observed even at a concentration of 1, 000mcg/ml.

Studies on the Breakdown of Resistance in the Blast Resistant Rice Variety, CO 29 in Tamil Nadu

CO 29, a high yielding short duration blast resistint rice variety has replaced the existing susceptible varieties in many parts of the Tamil Nadu. But during winter season 1966, CO 29 variety was found to be severely affected by the blast disease resulting in almost complete loss of crop in many parts of Coimbatore district. During 1967 winter season also, the blast incidence was noticed on CO 29 in many other districts in the Tamil Nadu. Such breakdown in resistance may be due to the change in environment as in the case of 'Polygenic resistance' or due to the development of new races of the pathogen as in the case of Single gene resistance' (Walker, 1959). Suryanarayanan (1958) reported that even the resistant varieties when subjected to low night temperature (20°C), showed characteristic blast lesions on inocula- tion with Piricularia oryzae Cav. Padmanabhan (1965) also has reported the occurence of races of P. oryzae in India. The present investigation was undertaken to elucidate the factors responsible for the breakdown of resistance to blast in CO 29 rice variety.

Studies on the Phenylphenol Derivatives with Biological Activity

More than ninety phenylphenol derivatives were tested for fungistatic activity toward ten species of agriculturally important fungi. One of N-methylcarbamates and some nitro- or chloro-substituted derivatives were highly toxic against Piricularia oryzae. From the relationship between the chemical structure and the activity, it is supposed that the reactivity, the permeability, the steric effect and the metabolic activation of the compound are the responsible factors for the fungistatic activity.

最上位節間の未抽出部がいもち病菌に侵された事例について

In 1965, draped parts of the first internode of some rice plants were evidently infected with Piricularia oryzae. This is a peculiar case since no report and observation have beeen made. The authers report the result of investigation on this epidemic disease appeared in Amagi District of Fukuoka Prefecture in the present paper. The investigations were made in 2 paddy fields planted with varieties, "Hoyoku" and "Norin No. 12", respectively. Approximately 1 to 2 percent of the draped part was infected with the rice blast, and usually one diseased spot per ear was found. The length of the spot is about 3 cm, and the distance from the ear neck to the center of the spot is 8 to 13 cm. This unique disease on the draped part commonly appears on the rice infected with leaf tongue blast disease, as well. The cause is not clear enough unless the inoculation test is conducted, however, the rice plant delaying the head sprouting finish due to the low temperature and much rainfall during the heading period may accept the disease.

Studies on the Phenylphenol Derivatives with Biological Activity

More than ninety phenylphenol derivatives were tested for fungistatic activity toward ten species of agriculturally important fungi. One of N-methylcarbamates and some nitro- or chloro-substituted derivatives were highly toxic against Piricularia oryzae. From the relationship between the chemical structure and the activity, it is supposed that the reactivity, the permeability, the steric effect and the metabolic activation of the compound are the responsible factors for the fungistatic activity.

Streptomyces citricolor nov. sp. and a new antibiotic, aristeromycin.

A new antibiotic, aristeromycin, was isolated from the culture filtrate of a new streptomyces, Streptomyces citricolor nov. sp. Aristeromycin is isolated using chromatography on active carbon, alumina and ion-exchange resin. Aristeromycin is isolated as colorless prism melting at 213-215°C (dec), and has the molecular formula C11H15O3N5. Its ultraviolet absorption maximum is observed at 262 mμ (El1%1cm 555). It shows inhibitory activities against Xantho monas oryzae and Piricularia oryzae in vitro as well as in vivo.

Inhibitory Effect of Pentachlorobenzyl alcohol (PCBA) on Sporulation of Piricularia oryzae Cavara

Pentachlorobenzyl alcohol (PCBA) is one of the most effective fungicides for the control of rice blast. When blast-infected rice seedlings on a nursery bed outdoors were sprayed with PCBA at 1000μg/ml, spore scattering from the infected seedlings was markedly inhibited from 2nd to 10th day after the spraying. Sporulation on lesions of the sprayed leaves was greatly suppressed during this period. When the leaves, on which PCBA had been sprayed, were detached and incubated at 28°C in a moist chamber, spores were produced as well as on leaves from unsprayed seedlings. The same result was obtained with the test using rice seedlings grown and inoculated under greenhouse conditions. On the contrary, phenylmercuric acetate (PMA, Hg-30 or Hg-20μg/ml) and blasticidin-S (Bc-S, 20 or 10μg/ml) inhibited the sporulation both on leaves of growing plants and on detached leaves. When these three compounds were sprayed on mycelial mats grown on a agar medium in petri dishes, PCBA did not inhibit the sporulation, whereas PMA and Bc-S, each at 40μg/ml, inhibited the sporulation by about 100 per cent. These results clearly indicate that sporulation-inhibiting effect of PCBA is not caused by the direct contact of the compound with the fungus but is caused by an interaction between the compound and the growing rice plant.

Ablastmycin, a new anti-piricularia antibiotic.

A new antibiotic, ablastmycin (C18H31N5O10, λmax 274mμ in 0.1N HCl, [α]25D=+60°in H2O), inhibiting Piricularia oryzae and Helminthosporiume was isolated. The producing strain was classified as Streptomyces aburaviensis var. ablastmyceticus. Production, isolation, purification and physico-chemical properties of this antibiotic are described.

Studies on fungicides. 18. Synthesis and antifungal activity of halogen substituted phenylhydrazine derivatives and related compounds

Comparative examinations were made on the activities against Piricularia oryzae using the halogen-substituted phenylpyrazolones, halogen-substituted β-acetylphenylhydrazines, and halogen-substituted phenylhydrazines synthesized in earlier work. The activities decreased in the order of hydrazines, acetylhydrazines, and pyrazolones. Assuming that the activity is due to the[chemical formula]skeleton, a series of compounds having this skeleton were synthesized, a total of over 200 compounds classified into 14 groups, and relationship between their structure and activity against rice blast has been discussed.

U.S.-Japan cooperative research on the international pathogenic races of the rice blast fungus, Piricularia oryzae Cav., and their international differentials

Research studies were conducted in Japan and the United States under a 3-year cooperative project in order to select an international set of rice varieties for differentiating the pathogenic races of Piricularia oryzae. Initially, the 39 varieties comprising the former United States, Japan and Taiwan differentials were used. As the studies progressed, 12 candidate varieties were selected. A total of 59 races were differentiated through use of the 12 varieties. Eight of the 12 candidate varieties were selected as the final set of international differentiating varieties: Raminad Str. 3; Zenith; NP-125; Usen; Dular; Kanto 51; Sha-tiao-tsao-S; and Caloro. Among P. oryzae isolates from several rice-producing countries, 32 international races were characterized.

Physiological Effects of Pentachlorobenzylalcohol on Rice Plants

Pentachlorobenzylalcohol (PCBA) is a new fungicide remarkably effective against rice blast caused by Piricularia oryzae Cavara. It is known that PCBA has many desirable characteristics as a rice blast fungicide; for example, nonphytotoxicity for every variety of plants tested and extremely low toxicity for the rat, mouse and small carp. One of the most striking characteristics of PCBA in comparison with the organic mercury fungicides is the excellent residual effect. However the antifungal activity in vitro of PCBA against rice blast fungus is too weak to be regarded as the origin of the efficacy.To know the physiological function of PCBA on the rice plant, the influence of PCBA on the constituents of nitrogen and carbohydrate in the rice plant was studied. The change of the ratio of these organic constituents of the PCBA-sprayed rice plant and the unsprayed has been traced at successive growth stages.The results obtained was summarized as follows:1. Spraying of PCBA on the rice plant appeared to cause the decrease of the ratio of total nitrogen in the leaf blade. In ripening stage, however, the ratio of total nitrogen was estimated in higher level in the PCBA-treated plant than in the untreated.2. Concerning water soluble- and protein-nitrogeous fractions the results showed the similar tendency to that of the total nitrogen ratio. The compounds with amino radicals, especially glutamic acid and aspartic acid, decreased considerably after the treatment of PCBA, and were maintained in relatively low level till the later growth stage.3. In the carbohydrate fractions, the ratio of crude starch estimated in the lower sheath of the rice plant sprayed with PCBA was much higher than that of the unsprayed plant. There was also appreciable difference in the accumulation of crude starch in the ear between the PCBA-sprayed plant and the unsprayed.

A. Sheath Inoculation Method to assess the Grade of Resistance or Susceptibility of Rice Plants to Piricularia oryzae

A. Sheath Inoculation Method to assess the Grade of Resistance or Susceptibility of Rice Plants to Piricularia oryzae

B. Studies on Media for Sporulation and Stock Cultures of Piricularia oryzae Cavara

1. The paper gives the results of experiments on the nuritional requirements of P. oryzae in media for abundant sporulation and stable stock cultures.2. A semi-synthetic medium, designated as the modified basic agar medium, was much more suitable for sporulation and stock culture with consistency for all the isolates of P. oryzae tested than the other agar media which have been commonly used.The constituents of the modified basic agar medium are as follows:Yeast extract powder 0.4% MgSO4⋅7H2O 0.06Glucose 0.4 CaCl2 0.10Tween 80 0.06 FeCl3⋅6H2O traceK2HPO4 0.06 Agar 2.03. The nutritional requirements seem to differ with the kind of biologic species identified on the basis of the appressorium type. The modified basic agar medium and potato sucrose agar seem to be favorabl for isolate No.8 CG-1, a homocaryon belonging to the biological species C-1, and some biologic species belonging to the mutant type. The former medium was suitable, in general, for the biologic species belonging to the wild type.4. Further fundamental studies on the nutritional physiology of each homocaryotic biological species of P. oryzae will be necessary for finding the medium or media suitable enough for uniform and abundant production of conidia and for stock culture stability.5. In conclusion, the writer again wishes to emphasize that all the basic studies on P. oryzae, in which sexual reproduction has not been found, absolutely need the homocaryotic biologic species with genetic stability-a need he has strongly expressed for many years.

キノリン誘導体について その11

Compounds I to (VI) were synthesized by the diazotization of aniline, p-thiocyanatoaniline, 3-chloro-4-thiocyanatoaniline, p-chloroanilne, p-nitroaniline, and o-chloroaniline, and application of 8-quinolinol to the diazonium salts in ethanol. The compound (VIII) was prepared by the diazotization of p-chloroaniline and application of 6-aminoquinoline to its salt. Antibacterial action in vitro of these compounds and those prepared earlier (IX to XXXIII), *3 was tested with Aspergillus niger, Trichophyton mentagrophytes Wachsman 640, Saccharomyces cerevisiae ATCC 9763, Trichophyton rubrum, Ophyobolus miyabeanus, Piricularia oryzae, and Cladosporium herbarum.

Effect of Blasticidin S on carbohydrate metabolism of Piricularia oryzae mycelium

1. When Piricularia oryzae was grown in the medium containing glucose alone as a carbon source, it was found that the carbohydrate of the mycelium was composed of glucose and its noncellulose polymer.2. Effects of Blasticidin S (BcS) and 2, 4-dinitrophenol on the utilization of glucose by P. oryzae were investigated. The growth-inhibitory concentration of BcS (1.0μg/ml) caused an accumulation of 70 percent ethanol-soluble polysaccharide in the mycelial cells and inhibited completely the synthesis of 70 percent ethanol-insoluble polysaccharide.3. The effect of BcS on glucose utilization was not altered by the addition of L-glutamic acid in the medium. Although the rates of oxygen uptake and glucose utilization by the mycelium treated with BcS were low, the rates were maintained undecreased during 4 hours' incubation in medium. In contrast, the rate of utilization of L-glutamic acid remained unchanged in the first 2 hours' incubation as compared with that by non-treated mycelium, but, after that time, no further utilization was found until 4 hours' incubation.