The cultivation of rust fungi upon artificial media

1974 ◽  
Vol 52 (4) ◽  
pp. 767-772 ◽  
Author(s):  
Frederick T. Wolf
Keyword(s):  
Hydrolytic Enzymes ◽  
Rust Fungi ◽  
Puccinia Graminis ◽  
Tissue Cultures ◽  
Melampsora Lini ◽  
Obligate Parasites ◽  
Pure Cultures ◽  
Physiological And Biochemical ◽  
Host Tissues ◽  
Puccinia Malvacearum

While the rust fungi have long been regarded as obligate parasites, within recent years nine species belonging to four different genera have been grown in pure culture in the laboratory. Gymnosporangium juniperi-virginianae and Uromyces caladii have been isolated from tissue cultures of their infected hosts. A culture of Puccinia malvacearum originated from a teliospore, promycelium, or basidiospore. Puccinia graminis tritici, P. graminis avenae, P. recondita trilici, P. helianthi, Melampsora lini, and Uromyces dianthi have been isolated from germinating uredospores. Melampsora lini has also been isolated through treatment of infected host tissues with hydrolytic enzymes. Some of the cytological, physiological, and biochemical findings resulting from studies of these pure cultures are discussed.

Axenic culture of flax rust isolated from cotyledons by cell-wall digestion

1972 ◽  
Vol 50 (12) ◽  
pp. 2601-2603 ◽  
Author(s):  
W. David Lane ◽  
Michael Shaw
Keyword(s):  
Cell Wall ◽  
Host Cell ◽  
Cell Walls ◽  
Hydrolytic Enzymes ◽  
Axenic Culture ◽  
Rust Fungi ◽  
Host Cells ◽  
Melampsora Lini ◽  
Large Numbers ◽  
Axenic Cultures

A technique is described for the isolation of colonies of flax rust (Melampsora lini (Ehrenb.) Lév., Race No. 3) from infected cotyledons. The technique depends on the digestion of the host cell walls with hydrolytic enzymes and washing of the liberated colonies. It is thus possible to collect large numbers of flax-rust colonies with only a few host cells adhering to them. Axenic cultures were established from colonies isolated in this way. This technique may be useful in establishing axenic cultures of other rust fungi.

Increased Lipoxygenase Activity is Involved in the Hypersensitive Response of Wheat Leaf Cells Infected with A virulent Rust Fungi or Treated with Fungal Elicitor

1986 ◽  
Vol 41 (5-6) ◽  
pp. 559-563 ◽  
Author(s):  
Carlos A. Ocampo ◽  
Bruno Moerschbacher ◽  
Hans J. Grambow
Keyword(s):  
Hypersensitive Response ◽  
Hypersensitive Reaction ◽  
Rust Fungi ◽  
Lipoxygenase Activity ◽  
Puccinia Graminis ◽  
Compatible Interaction ◽  
Wheat Leaf ◽  
Wheat Leaves ◽  
Germ Tubes ◽  
Wheat Rust

The hypersensitive reaction in incompatible wheat-rust interactions is characterized by an increase in lipoxygenase activity detectable as early as 28 h after penetration of the pathogen. In contrast, lipoxygenase activity in the compatible interaction did not increase until the onset of sporulation.Lipoxygenase activity also increased following treatment of wheat leaves with an elicitor fraction from germ tubes of Puccinia graminis tritici.

In vitro growth of wheat and flax rust fungi on complex and chemically defined media

1974 ◽  
Vol 52 (6) ◽  
pp. 1183-1195 ◽  
Author(s):  
A. Bose ◽  
Michael Shaw
Keyword(s):  
Liquid Medium ◽  
Aspartic Acid ◽  
Yeast Extract ◽  
Australian Isolate ◽  
Puccinia Graminis ◽  
Good Growth ◽  
Complex Media ◽  
Mineral Salts ◽  
Melampsora Lini

Growth from uredospores seeded in axenic culture is described for several races of Puccinia graminis Pers. f. sp. tritici (Erikss. and Henn.) and race 3 of Melampsora lini (Ehrenb.) Lév. on complex media containing peptone, yeast extract, and bovine serum albumin (BSA); and for an Australian isolate of Puccinia graminis, race 126-ANZ 6,7, and Melampsora lini, race 3, on chemically defined, liquid media.Of six North American isolates of Puccinia graminis only race 38 formed colonies approaching those of race 126-ANZ 6,7 in final size and general morphology on complex media. 5′AMP had no effect on the growth of 126-ANZ 6,7, but cyclic AMP inhibited growth after uredospore germination. Good growth and sporulation were obtained with 126-ANZ 6,7, but not with the other isolates tested, using a new, chemically defined liquid medium, sterilized by millipore filtration, and containing glucose, Czapek's minerals plus micronutrients, Ca2+, glucose and aspartic acid, glutathione, and cysteine. Uredospores produced in culture reinfected exposed mesophyll tissue, but not intact seedling leaves of wheat.Highly reproducible growth and sporulation of Melampsora lini, race 3, were obtained routinely on a solid medium containing Difco-Bacto agar, sucrose, Knop's minerals, micronutrients, yeast extract, peptone, and BSA. Vegetative cultures, capable of reinfecting the cut ends of surface-sterilized flax cotyledons, could be maintained indefinitely by subdivision before sporulation and transfer to the same medium minus BSA. Evidence is presented that BSA stimulated the development of colonies and the formation of uredospores. The mode of action of BSA is unknown, but it could not be replaced by putrescine.A new chemically defined, liquid medium containing sucrose, Knop's mineral salts, micronutrients, aspartic (or glutamic) acid, and cysteine supported the growth of colonies of Melampsora lini in a highly reproducible manner. The formation of uredospores and teliospores by these colonies was controlled by (a) the level of Ca2+ (as Ca(NO3)2∙4H2O), (b) the concentration of aspartic acid, and (c) the number of colonies per flask. At inoculum levels giving 40 to 60 colonies per flask, in media containing 8.5 mM Ca+ and 45 mM aspartic acid, uredospore formation occurred in 60 to 70% of the colonies. A decrease in the Ca2+ level to 4.25 mM, or a decrease in aspartic acid to 22.5 mM, or adjustment of the inoculum level to give about 10 colonies per flask each resulted in only infrequent sporulation. The uredospores produced in vitro infected intact, 1-week-old flax cotyledons in a normal manner.

Comparison of hydrolytic enzyme systems in pure culture and activated sludge under different electron acceptor conditions

1998 ◽  
Vol 37 (4-5) ◽  
pp. 335-343 ◽  
Author(s):  
Rajeev Goel ◽  
Takashi Mino ◽  
Hiroyasu Satoh ◽  
Tomonori Matsuo
Keyword(s):  
Enzyme Activity ◽  
Activated Sludge ◽  
Electron Acceptor ◽  
Bacillus Amyloliquefaciens ◽  
Enzyme System ◽  
Weak Link ◽  
Batch Reactor ◽  
Hydrolytic Enzyme ◽  
Hydrolytic Enzymes ◽  
Pure Cultures

Enzymatic hydrolysis under different electron acceptor conditions in nutrient removal activated sludge treatment processes is a weak link in the Activated Sludge Model no. 2 (Henze et al., 1995). An experimental study was undertaken to gain insight into the hydrolysis process with specific focus on hydrolysis kinetics and rates under different electron acceptor conditions. Two pure cultures, Bacillus amyloliquefaciens (Gram positive) and Pseudomonas saccharophila (Gram negative) were chosen for the study. In addition, activated sludge grown in an anaerobic-aerobic system was tested for enzymatic activity using starch as the model substrate. The hydrolytic enzymes were found to be released into the bulk in pure cultures whereas the enzyme activity was found to be mainly associated with the cell surfaces in activated sludge. Further, it was observed that the development of the hydrolytic enzyme system in Bacillus amyloliquefaciens and P. saccharophila is strongly suppressed under anoxic and anaerobic conditions. However, the effect of anaerobic and aerobic incubation on hydrolytic enzyme activity in activated sludge was found to be small. Starch hydrolysis kinetic data from batch experiments with activated sludge followed substrate saturation kinetics that were linear with biomass concentration. Finally, the similar hydrolytic enzyme activities observed under anaerobic and aerobic phases of a sequencing batch reactor are explained by considering the aspects of enzyme location and enzyme system development under aerobic and anaerobic phases. It is proposed that the floc bound enzymes are recycled in a single sludge system so that an equilibrium exists between enzyme loss and synthesis at steady state.

THE BIOSYNTHESIS OF INDOLEACETIC ACID IN MELAMPSORA LINI (PERS.) LEV.

1962 ◽  
Vol 40 (2) ◽  
pp. 309-315 ◽  
Author(s):  
B. I. Sahai Srivastava ◽  
Michael Shaw
Keyword(s):  
Incubation Medium ◽  
Plant Material ◽  
Indoleacetic Acid ◽  
Extension Growth ◽  
Tissue Cultures ◽  
Melampsora Lini ◽  
Solvent Systems

Mycelium of Melampsora was grown on flax cotyledons in tissue cultures. Mycelium and uredospores were incubated with DL-tryptophane-2-C14 and uredospores were incubated with L-tryptophane. Acid and neutral ether-soluble and aqueous fractions of the plant material and incubation medium were chromatographed and sprayed with chromogenic agents or radioautographed. Radioactive indoleacetic acid was produced in small amounts by both mycelium and spores (yield = 0.016% in 8 hours). The auxin was identified on the basis of its Rf values in two solvent systems, its reactions with Ehrlich and Salkowski reagents, and its ability to promote extension growth of Avena coleoptiles. Evidence for the formation of indoleacetaldehyde was also obtained. Several other radioactive and Ehrlich-positive products of tryptophane metabolism were detected but not identified. One of these could have been indolepyruvic acid. Tryptamine and indoleacetonitrile were not found. The results suggest that, in Melampsora, the synthesis of indoleacetic acid from tryptophane proceeds through indolepyruvic acid and indoleacetaldehyde.

Mitosis and cell division in some cereal rust fungi. II. The processes of mitosis and cytokinesis

1976 ◽  
Vol 54 (9) ◽  
pp. 995-1009 ◽  
Author(s):  
D. E. Harder
Keyword(s):  
Cell Division ◽  
Nuclear Envelope ◽  
Mitotic Spindle ◽  
Rust Fungi ◽  
Puccinia Graminis ◽  
Carbohydrate Storage ◽  
Spindle Poles ◽  
Nucleolar Extrusion

Before mitosis in intercellular Puccinia graminis f. sp. avenae, P. coronata f. sp. avenue, and axenic P. graminis f. sp. tritici and P. coronata, the nuclei were reduced in size by nucleolar extrusion and (or) partitioning of variable portions of the nucleus. Also there was increased vesiculation in the cytoplasm with a corresponding increase in lipid and carbohydrate storage material.The mitotic spindle first formed in one corner of the nucleus, then elongated until the spindle poles were oriented at either end of the nucleus. During the intermediate stages of mitosis the chromatin was arranged around the periphery of the spindle, which consisted mostly of chromosomal fibres. In the later stages the nucleus elongated and became dumbbell-shaped, with long straight fibres passing through the nucleus from pole to pole. The end of mitosis was marked by the chromatin assuming a ‘two-track’ configuration at the poles on either side of the intranuclear fibres and by the breakdown of the nuclear envelope in the constricted region of the dumbbell-shaped nucleus.After the daughter nuclei had separated, they migrated into new hyphal branches and septum synthesis was subsequently initiated. The septa grew by centripetal invagination in both the intercellular and the axenic hyphal states. There were often accumulations of mitochondria in the region of septal growth. Mature septa of intercellular P. coronata and axenic P. coronata and P. graminis tritici were typical of those found elsewhere in the rust fungi.

FURTHER EVIDENCE OF RESISTANCE IN BERBERIS VULGARIS TO RACE 15B OF PUCCINIA GRAMINIS f. sp. TRITICI

1958 ◽  
Vol 36 (3) ◽  
pp. 351-355 ◽  
Author(s):  
G. J. Green ◽  
T. Johnson
Keyword(s):  
Common Wheat ◽  
Stem Rust ◽  
Wheat Variety ◽  
Circumstantial Evidence ◽  
Puccinia Graminis ◽  
Wheat Stem Rust ◽  
Berberis Vulgaris ◽  
Pure Cultures ◽  
The Common ◽  
Common Wheat Variety

Plants of common barberry (Berberis vulgaris L.) were inoculated to determine their reaction to race 15B of wheat stem rust (Puccinia graminis Pers. f. sp. tritici Erikss. & Henn.). Only resistant-type infections occurred on plants inoculated with two pure cultures of race 15B-4 (Can.). Strong circumstantial evidence for the resistance of common barberry to race 15B was obtained from inoculations with sporidia from teliospores produced in the field. Sporidia from teliospores collected from the emmer wheat variety Vernal, which is selective for race 15B, produced only infections of a resistant type, and those from the common wheat variety Lee, also selective for 15B, caused both resistant and susceptible types of infections. Transfer of aeciospores to wheat from the susceptible type demonstrated that 15B was not present. Sporidia from teliospores on the varieties Reliance and Mentana, which are not selective for this race, caused infections of a susceptible type. Resistant-type and susceptible-type infections appeared when barberry leaves were infected with races 29 and 48A.

scholarly journals Host resistance to fungi, chiefly in relation to obligate parasites

1948 ◽  
Vol 135 (879) ◽  
pp. 180-186 ◽  
Keyword(s):  
Culture Media ◽  
Rust Fungus ◽  
Wheat Variety ◽  
Structural Features ◽  
Biochemical Properties ◽  
Puccinia Graminis ◽  
Powdery Mildews ◽  
Obligate Parasites ◽  
Resistance To Invasion ◽  
Germ Tubes

The factors in the host conferring resistance to invasion by fungi which are obligate parasites are generally much more difficult to elucidate than where facultative parasites are involved, for the latter can be grown on culture media and their enzyme systems and other biochemical properties can be investigated in detail. At present, apart from the early stages after spore germination, a rust fungus can only be studied in relation to its host, and a clear analysis of the physiology of parasite and host respectively has not yet been achieved. Even in the rusts, however, structural features of the host occasionally confer some degree of resistance. In the wheat variety, Webster, profuse development of sclerenchyma in the stem checks mycelial growth of Puccinia graminis and confers a measure of resistance (Stakman, Levine & Griffee 1925), although other factors are also involved such as the tough character of the epidermis which impedes exposure of the pustules. Young barberry leaves are readily penetrated by the sporidial germ-tubes of P. graminis , whereas old leaves, provided with a thicker cuticle, are not infected. There is evidence, too, that the relative thickness of the cuticle is a factor in determining whether powdery mildews cause infection (Corner 1935). In connexion with attack by P. graminis on wheat it has been suggested (Hart 1929) that in some varieties tardy opening of the stomata in the morning confers a kind of functional resistance because the delicate germ-tubes of the spores on the surface are desiccated before penetration can be achieved. There is, however, some uncertainty about this interpretation.

scholarly journals INFECTIOUS CATARRH OF MICE

1937 ◽  
Vol 65 (6) ◽  
pp. 851-860 ◽  
Author(s):  
John B. Nelson
Keyword(s):  
Direct Contact ◽  
Primary Cultures ◽  
Tissue Cultures ◽  
Pure Cultures ◽  
Primary Tissue ◽  
Close Parallel ◽  
Experimental Disease

Evidence is presented that the etiology of infectious murine catarrh is specifically referable to the coccobacilliform bodies. The disease was regularly produced in normal mice by the nasal instillation of primary tissue cultures. In the presence of the X bacillus, transfers of primary cultures were usually uninfective. Pure cultures, however, retained their pathogenicity through as many as 12 transfers. The onset and progress of the experimental disease were somewhat retarded in comparison with the natural disease, but in general there was a close parallel. Mice injected with cultures did, however, show a significant decrease in the incidence of rhinitis. Transmission by direct contact was demonstrated in the presence of a rhinitis but not in its absence.

scholarly journals II. On the histology of uredo dispersa , erikss., and the "mycoplasm" hypothesis

1904 ◽  
Vol 196 (214-224) ◽  
pp. 29-46 ◽  
Keyword(s):  
Royal Society ◽  
Rust Fungus ◽  
Rust Fungi ◽  
Pure Cultures ◽  
The One ◽  
Microscopic Investigations

There are still so many and such important gaps in our knowledge of the biology of the Uredineæ, that no one will expect an apology for a serious attempt to fill any of them, and the less so in the particular case of the Rust-fungi of the Gramineæ and cereals, because, notwithstanding the numerous researches which have succeeded each other since De Bary’s classical investigations, the whole question of the origin and spread of epidemics of rust has been raised again owing to the remarkable discovery of the specialised parasitism exhibited by certain adapted races of these fungi, and to the still more remarkable assumptions published by Eriksson in what is known as the “Mycoplasm” hypothesis. I have from time to time brought before the notice of the Royal Society and elsewhere, the results of my own investigations into the biology of that particular form of Rust-fungus known as Puccinia dispersa , Erikss., more especially with reference to its peculiar parasitism on the grasses of the genus Bromus , and have treated successively of the questions of predisposition and immunity, of the relations between the host and the parasite, of the method of pure cultures of such a Uredine as the one in question, and of the effects of mineral starvation on its parasitism. In all these cases, however, the studies were chiefly experimental, dealing with the physiology of infection, and the publication of the results of the extensive and far more laborious microscopic investigations was reserved, a few remarks only being made here and there showing the directions in which these were leading from time to time.

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