Sporulation and pathogenicity of an Australian isolate of wheat rust grown in vitro

1971 ◽  
Vol 49 (11) ◽  
pp. 1961-1964 ◽  
Author(s):  
A. Bose ◽  
Michael Shaw
Keyword(s):  
Surface Coating ◽  
Germ Tube ◽  
Australian Isolate ◽  
Puccinia Graminis ◽  
Lower Epidermis ◽  
Mineral Salts ◽  
Wheat Leaves ◽  
Wheat Rust ◽  
Serum Albumen

Colonies of Puccinia graminis Pers. f. sp. tritici Erikss. & Henn., race ANZ 126-6,7 were grown from uredospores on Czapek's mineral salts, 3% glucose, 0.1% Evans' peptone, plus defatted bovine serum albumen. Dikaryotic vegetative hyphae apparently developed from centers of germ tube anastomosis, without the formation of typical infection structures. Typical pigmented uredospores and teliospores were formed after 6 to 8 weeks growth. Both spore forms were coated with a layer of material which was visible under the scanning electron microscope and was not observed on uredospores grown on intact wheat leaves. The uredospores were capable of infecting the mesophyll of wheat leaves exposed by stripping back the lower epidermis. The possibility is considered that the surface coating of uredospores grown in vitro is related to their inability to infect intact leaves via the stomata.

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.

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.

Alterations in 1,4-Benzoxazinone Levels Following Inoculation with Stem Rust in Wheat Leaves Carrying Various Alleles for Resistance and Their Possible Role as Phytoalexins in Moderately Resistant Leaves

1990 ◽  
Vol 45 (11-12) ◽  
pp. 1151-1155 ◽  
Author(s):  
Claudia Bücker ◽  
Hans J. Grambow
Keyword(s):  
Triticum Aestivum ◽  
Stem Rust ◽  
Triticum Aestivum L ◽  
Puccinia Graminis ◽  
Conversion Product ◽  
Near Isogenic Lines ◽  
Wheat Leaves ◽  
Infection Types ◽  
Moderately Resistant

The contents of 1,4-benzoxazinone derivatives in wheat plants infected with Puccinia graminis Pers. f. sp. tritici Ericss. & Henn, race 32, and in uninfected controls were examined in four near-isogenic lines of different infection types: Triticum aestivum L., cultivar Prelude Sr5 (highly resistant), Sr24, Sr26 (moderately resistant), and srx (susceptible). In all infection types the contents of DIMBOA -glc and HMBOA -glc decrease with time in the uninfected controls as well as in the infected plants. However, following inoculation, the synthesis of HDIBOA -glc is drastically increased in the moderately resistant cultivars. The results suggest that this fully methylated 1,4-benzoxazinone may function as a phytoalexin in this type of interaction. The benzoxazolinone MBOA which has been described as an in vitro conversion product of the benzoxazinones mentioned above is not detected in inoculated or uninoculated leaves.

A SURVEY OF AMINO ACID CONTENT OF THE UREDOSPORES OF SOME RACES OF WHEAT RUST (PUCCINIA GRAMINIS)

1960 ◽  
Vol 38 (2) ◽  
pp. 244-247 ◽  
Author(s):  
M. E. McKillican
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Column Chromatography ◽  
Acid Content ◽  
Free Amino Acids ◽  
Free Amino ◽  
Amino Acid Content ◽  
Puccinia Graminis ◽  
Wheat Leaves ◽  
Wheat Rust

The free and combined amino acids of seven samples of wheat rust were analyzed quantitatively by paper and column chromatography and compared with the amino acids present in uninfected wheat leaves. All races studied contained different proportions of free amino acids.

In vitro growth of gelatin suspensions of uredospores of Puccinia graminis f. sp. tritici

1969 ◽  
Vol 47 (8) ◽  
pp. 1291-1293 ◽  
Author(s):  
M. D. Coffey ◽  
A. Bose ◽  
Michael Shaw
Keyword(s):  
Basic Medium ◽  
Australian Isolate ◽  
Brown Pigment ◽  
Puccinia Graminis ◽  
Partial Recovery ◽  
It Diffusion ◽  
The Media ◽  
Agar Surface ◽  
Bacto Agar

A comparison was made of the growth of the Australian isolate of Puccinia graminis Pers. f. sp. tritici Eriks. & E. Henn. race ANZ 126-6,7 on 1.5% Difco Bacto-Agar using water and 15% gelatin as suspension media for seeding uredospores on the media. A range of media was tested, the basic constituents being 3% glucose, Czapek's minerals, peptone, and 1% bovine serum albumin. Spores embedded in gelatin gave much better growth than those applied to the agar surface in water suspension in all media. Sodium citrate (0.2%) inhibited growth; pectin (0.2%) did also, but partial recovery occurred later. Best growth was on the basic medium seeded with uredospores in gelatin. The mycelium was white and fluffy in appearance at first, but collapsed later as a dense brown stroma developed beneath it. Diffusion of brown pigment into the agar medium took place with the gelatin, but not the water series. Sporulation was observed after 60 days in a few colonies and was located in the brown stroma. Spores were non-pigmented, oval in shape, and similar in size to typical uredospores. It is suggested that the physical environment around the spores affects growth.

Nuclear condition, types of hyphal development from differentiating, and nondifferentiating uredosporelings, and effect of 3,3′-bis-indolylmethane on Puccinia graminis f.sp. tritici in vitro

1978 ◽  
Vol 56 (7) ◽  
pp. 736-741 ◽  
Author(s):  
Hans J. Grambow ◽  
Dietmar Müller
Keyword(s):  
Growth Rate ◽  
Germ Tube ◽  
Hyphal Growth ◽  
Tube Growth ◽  
Puccinia Graminis ◽  
Unknown Factor ◽  
Germ Tubes ◽  
Germ Tube Growth ◽  
Nuclear Condition

In vitro Puccinia graminis f.sp. tritici, race 32, produced dikaryotic hyphae from infection structures, corresponding to appressoria and substomatal vesicles (differentiated), which are formed by germ tubes as a response to a heat shock within 24 h after seeding the spores. Dikaryotic hyphae also formed spontaneously from nondifferentiated senescing germ tubes 3–4 days after seeding the spores. The hyphae which originated from the different structures did not appear to be different with regard to nuclear condition, morphological appearance, and fluorescence properties as a consequence of Feulgen staining. 3,3′-Bis-indolylmethane (BIM) increased the hyphal growth rate in contrast with the germ tube growth rate. It also supported the transition from germ tube growth to hyphal growth. The possible mode of action of BIM and the involvement of an unknown factor which represses hyphal growth are discussed.

Accumulation of phytoalexins in the compatible interaction between Cladosporium fulvum and tomato in relation to colonization

1991 ◽  
Vol 69 (4) ◽  
pp. 822-830 ◽  
Author(s):  
Ulisses G. Batista ◽  
Verna J. Higgins
Keyword(s):  
Suspension Culture ◽  
Germ Tube ◽  
Plant Cells ◽  
Cladosporium Fulvum ◽  
In Vitro Experiments ◽  
Compatible Interaction ◽  
Leaf Mold ◽  
Production And Distribution ◽  
Fulvia Fulva

The production and distribution of the phytoalexin falcarindiol in tomato foliage infected with leaf mold was examined to determine how the fungus Cladosporium fulvum is able to colonize and sporulate in an apparently antifungal environment. In a compatible interaction (cv. Potentate – C. fulvum race 2.3), by 12 and 15 days after inoculation, solvent-extractable falcarindiol and two other phytoalexins from tomato, compound 2 (probably falcarinol) and compound 3 (unidentified), reached concentrations considerably in excess of ED50 values for inhibition of the fungus. In contrast, intercellular (apoplastic) fluids obtained from similarly infected leaflets contained only traces of falcarindiol. ED50 values for germination and germ-tube growth of C. fulvum increased as the incubation time was extended, suggesting that adaptation or recovery was possible at the concentrations tested. In in vitro experiments, C. fulvum appeared to readily metabolize falcarindiol, as did a Lycopersicon cell suspension culture. Binding of falcarindiol to living and dead fungal and plant cells was also observed. Falcarindiol, injected into tomato leaflets, decreased rapidly and was only recovered in trace amounts by 24 h. The results suggest that falcarindiol and probably the two other phytoalexins do not reach sufficient concentrations in the apoplast of an infected susceptible leaf to have an effect on growth and sporulation of C. fulvum. Key words: leaf mold, Fulvia fulva, falcarindiol, falcarinol.

Aliphatic acids as spore germination inhibitors of wood-decay fungi in vitro

1985 ◽  
Vol 63 (2) ◽  
pp. 337-339 ◽  
Author(s):  
Elmer L. Schmidt
Keyword(s):  
Spore Germination ◽  
Germ Tube ◽  
White Rot Fungi ◽  
Wood Decay ◽  
White Rot ◽  
Malt Extract ◽  
Decay Fungi ◽  
Aliphatic Acids ◽  
Wood Decay Fungi

Influences of eight saturated aliphatic acids (C5–C10, C12, and C16) on basidiospores of four isolates of wood-decay fungi (Poria tenuis and Trametes hispida, white rot fungi, and two isolates of the brown rot fungus Gloeophyllum trabeum) were observed in vitro. Spore responses after 24 h on malt extract agar containing 10, 102 or 103 ppm of each acid included normal germination, delay of germ tube emergence, vacuolation and degeneration of spore cytoplasm, and prevention of germ tube development without spore destruction. Acids of chain length C5–C10 prevented spore germination and killed spores of all fungi at concentrations of 20–50 ppm in media, whereas other acids tested were less active. Spore germination assay of decay fungi may prove useful as a screening tool to compare potency of wood preservatives.

scholarly journals Application of Double-Strand RNAs Targeting Chitin Synthase, Glucan Synthase, and Protein Kinase Reduces Fusarium graminearum Spreading in Wheat

2021 ◽  
Vol 12 ◽  
Author(s):  
Peng Yang ◽  
Shu-Yuan Yi ◽  
Jun-Na Nian ◽  
Qing-Song Yuan ◽  
Wei-Jie He ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Fusarium Graminearum ◽  
Fungal Pathogen ◽  
Chitin Synthase ◽  
Mycelium Growth ◽  
Rnai Construct ◽  
Glucan Synthase ◽  
Kinase C ◽  
Wheat Leaves

Controlling the devastating fungal pathogen Fusarium graminearum (Fg) is a challenge due to inadequate resistance in nature. Here, we report on the identification of RNAi molecules and their applications for controlling Fg in wheat through silencing chitin synthase 7 (Chs7), glucan synthase (Gls) and protein kinase C (Pkc). From transgenic Fg strains four RNAi constructs from Chs7 (Chs7RNAi−1, −2, −3, and −4), three RNAi constructs from Gls (GlsRNAi−2, −3, and −6), and one RNAi construct from Pkc (PkcRNAi−5) were identified that displayed effective silencing effects on mycelium growth in medium and pathogenicity in wheat spikes. Transcript levels of Chs7, Gls and Pkc were markedly reduced in those strains. Double-strand RNAs (dsRNAs) of three selected RNAi constructs (Chs7RNAi-4, GlsRNAi-6 and PkcRNA-5) strongly inhibited mycelium growth in vitro. Spray of those dsRNAs on detached wheat leaves significantly reduced lesion sizes; the independent dsRNAs showed comparable effects on lesions with combination of two or three dsRNAs. Expression of three targets Chs7, Gls, and Pkc was substantially down-regulated in Fg-infected wheat leaves. Further application of dsRNAs on wheat spikes in greenhouse significantly reduced infected spikelets. The identified RNAi constructs may be directly used for spray-induced gene silencing and stable expression in plants to control Fusarium pathogens in agriculture.

Sign in / Sign up

Export Citation Format

Share Document