THE PHYSIOLOGY OF HOST-PARASITE RELATIONS: XII. A CYTOPHOTOMETRIC STUDY OF THE DISTRIBUTION OF DNA AND RNA IN RUST-INFECTED LEAVES

1962 ◽  
Vol 40 (11) ◽  
pp. 1533-1544 ◽  
Author(s):  
H. S. Whitney ◽  
Michael Shaw ◽  
J. M. Naylor
Keyword(s):  
Puccinia Graminis ◽  
Mesophyll Cells ◽  
Reaction Type ◽  
Dna And Rna ◽  
Azure B ◽  
Cytophotometric Study ◽  
Mother Cells ◽  
Host Parasite ◽  
Wheat Rust

Uninfected and rusted leaves of Little Club wheat (reaction type 4) were sectioned at intervals up to 15 days after inoculation with Puccinia graminis tritici Erikss. and Henn., race 15B. Infection caused a decrease in the size of the chloroplasts, an increase in size followed by a collapse of the nuclei in the mesophyll cells and an increase in the size of the nucleoli. These effects also occurred, but more rapidly, in infected leaves of Khapli wheat (rust reaction type 1). They were most pronounced in the tissue beneath uredia. Cytophotometry of nuclei in Little Club by the 'two-wavelength' method after staining with the Feulgen reagent showed that there was no increase in the level of DNA in enlarged nuclei at 6 days after inoculation; collapse of the nuclei at 15 days after inoculation was accompanied by the loss of 60% of the DNA originally present. Cytophotometry of nucleoli in nuclei in mesophyll cells stained with azure B after selective removal of DNA with DNase showed that nucleolar enlargement was accompanied by a significant (P = 0.05) increase in RNA. The fungal nuclei stained with the Feulgen reagent, but not after treatment with DNase. The cytoplasm in fungal hyphae, haustorial mother cells and haustoria stained heavily with azure B, but not after treatment with RNase. The absorption spectrum of the stained mycelium was characteristic of the RNA - azure B complex. The results are discussed.

THE PHYSIOLOGY OF HOST–PARASITE RELATIONS: XVIII. DISTRIBUTION OF TRITIUM-LABELLED CYTIDINE, URIDINE, AND LEUCINE IN WHEAT LEAVES INFECTED WITH THE STEM RUST FUNGUS

1967 ◽  
Vol 45 (5) ◽  
pp. 555-563 ◽  
Author(s):  
P. K. Bhattacharya ◽  
Michael Shaw
Keyword(s):  
Stem Rust ◽  
Rust Fungus ◽  
Host Cells ◽  
Fungal Mycelium ◽  
Puccinia Graminis ◽  
Mesophyll Cells ◽  
Wheat Leaves ◽  
Host Parasite

Wheat leaves were detached 6 days after inoculation with the stem rust fungus (Puccinia graminis var. tritici Erikss. and Henn.) and fed with tritiated leucine, cytidine, uridine, or thymidine. Mesophyll cells in infected zones incorporated more leucine into protein and more cytidine and uridine into RNA than did cells in adjacent uninfected tissue. Leucine, cytidine, and uridine were also heavily incorporated by fungal mycelium and developing uredospores. Grain counts over host nuclei in the infected zone were two to three-fold of those over nuclei in adjacent uninfected zones. There was no detectable incorporation of thymidinemethyl-3H into either the fungus or the host cells. The results are discussed.

Electron microscopy of susceptible and resistant near-isogenic (sr6/Sr6) lines of wheat infected by Puccinia graminis tritici. III. Ultrastructure of incompatible interact

1979 ◽  
Vol 57 (23) ◽  
pp. 2626-2634 ◽  
Author(s):  
D. E. Harder ◽  
D. J. Samborski ◽  
R. Rohringer ◽  
S. R. Rimmer ◽  
W. K. Kim ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Stem Rust ◽  
Stem Rust Resistance ◽  
Temperature Sensitive ◽  
Puccinia Graminis ◽  
Cell Necrosis ◽  
Mitochondrial Membranes ◽  
Wheat Stem Rust ◽  
Mesophyll Cells ◽  
Mother Cells

The interaction between avirulent wheat stem rust and wheat mesophyll cells containing the temperature-sensitive Sr6 gene for stem rust resistance was studied by electron microscopy. Mesophyll cells that were invaded at 26 °C (conditioning compatibility) did not develop any signs of incompatibility after they were transferred to 19 °C, at which temperature incompatibility is normally expressed. In host tissue that appeared to be invaded after the change from 26 to 19 °C, the early ultrastructural symptoms of incompatibility were a more electron-dense and often perforated invaginated host plasmalemma, disruptions of the noninvaginated host plasmalemma, vacuolation of the cytoplasm, and accumulations of electron-dense material along the membranes of the vacuoles. At later stages in the development of incompatible interactions, the electron-dense accumulations along the vacuole membranes increased in size and occurred along chloroplast and mitochondrial membranes. Eventually, the entire protoplasts were electron dense and collapsed. In haustoria and haustorial mother cells, incompatibility was usually expressed by a uniform increase in electron density of the cytoplasm. In the Sr6/P6 interaction at 19 °C, host cell necrosis was not always accompanied by fungal necrosis or vice versa. In Sr5/P5 interactions, which were examined for comparison, the intracellular symptoms of incompatibility were similar to those of the Sr6/P6 interactions.

The physiology of host–parasite relations. XIX. Further observations on nucleoprotein changes in wheat leaf nuclei during rust infection

1968 ◽  
Vol 46 (1) ◽  
pp. 11-16 ◽  
Author(s):  
P. K. Bhattacharya ◽  
Michael Shaw ◽  
J. M. Naylor
Keyword(s):  
Stem Rust ◽  
Rust Fungus ◽  
Puccinia Graminis ◽  
Mesophyll Cells ◽  
Rust Infection ◽  
Puccinia Graminis Tritici ◽  
Wheat Leaf ◽  
Host Parasite

Cytophotometric measurements of DNA (Feulgen) and protein-bound lysine and arginine (fluorodinitrobenzene-Sakaguchi) were made on nuclei in mesophyll cells of infected and uninfected leaves of Little Club wheat at intervals of 2 to 4 days up to 13 days after inoculation with uredospores of race 15B of the stem rust fungus (Puccinia graminis tritici Erikss. and Henn.). No change in host DNA was found within 6 days after inoculation, but there were marked decreases in protein-bound lysine and arginine as early as 2 days after inoculation. The DNA/lysine and DNA/arginine ratios were higher in rust-affected host nuclei, but infection did not alter the ratio of protein-bound lysine to arginine. In another series of measurements it was shown that rust infection caused striking increases in the volume and the RNA and protein contents of host nucleoli. These changes persisted even in advanced infections.All the results are consistent with our earlier observations and indicate that profound changes in nuclear metabolism are induced by infection with the rust fungus.

THE PHYSIOLOGY OF HOST–PARASITE RELATIONS: IV. THE EFFECT OF MALEIC HYDRAZIDE AND INDOLEACETIC ACID ON THE RUST RESISTANCE OF KHAPLI AND LITTLE CLUB WHEATS

1957 ◽  
Vol 35 (4) ◽  
pp. 449-455 ◽  
Author(s):  
D. J. Samborski ◽  
Michael Shaw
Keyword(s):  
Growth Inhibition ◽  
Stem Rust ◽  
Rust Resistance ◽  
Indoleacetic Acid ◽  
Maleic Hydrazide ◽  
Sand Culture ◽  
Simultaneous Application ◽  
Reaction Type ◽  
Host Parasite

Little Club (rust reaction type 4) and Khapli (rust reaction type 1 with race 15B) wheats were grown in sand culture in 1-qt. crocks or 5-in. pots. Daily applications of maleic hydrazide or indoleacetic acid were started 5 days before (10 days after sowing), on the day of, and 5 days after inoculation with stem rust (Race 15B) and were continued for about three weeks. Maleic hydrazide inhibited growth and, at 5 and 10 mg. per pot, flowering. Type 4 pustules developed on Khapli plants treated with 5 and 10 mg. of maleic hydrazide daily from the 5th day before and from the day of inoculation. Indoleacetic acid (0.5 mg. per pot from the 10th day after sowing) stimulated growth and flowering and slightly increased the resistance of Khapli. Treatments started 5 days after inoculation had no effect on rust development on Khapli, and none of the treatments altered the rust reaction of Little Club. Spores produced on plants treated with maleic hydrazide gave normal rust reactions on untreated plants.The effect of maleic hydrazide on the plants and on rust development was not altered by the simultaneous application of uracil, which reversed the growth inhibition caused by thiouracil. Thiouracil inhibited rust development in the presence of maleic hydrazide.

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.

scholarly journals Expanded DNA and RNA Trinucleotide Repeats in Myotonic Dystrophy Type 1 Select Their Own Multitarget, Sequence-Selective Inhibitors

Biochemistry ◽  
2020 ◽  
Vol 59 (37) ◽  
pp. 3463-3472
Author(s):  
Lauren D. Hagler ◽  
Long M. Luu ◽  
Marco Tonelli ◽  
JuYeon Lee ◽  
Samuel M. Hayes ◽  
...  
Keyword(s):  
Myotonic Dystrophy ◽  
Trinucleotide Repeats ◽  
Myotonic Dystrophy Type 1 ◽  
Myotonic Dystrophy Type ◽  
Selective Inhibitors ◽  
Dna And Rna

THE PHYSIOLOGY OF HOST–PARASITE RELATIONS: XVI. FINE STRUCTURE OF THE NUCLEUS IN THE RUST-INFECTED MESOPHYLL CELLS OF WHEAT

1966 ◽  
Vol 44 (5) ◽  
pp. 669-673 ◽  
Author(s):  
M. S. Manocha ◽  
Michael Shaw
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Electron Density ◽  
Mesophyll Cells ◽  
Host Parasite ◽  
Late Stages ◽  
Dense Chromatin

The nuclei in rust-infected mesophyll cells of Little Club wheat were examined by electron microscopy. There was a marked increase in the electron density of the diffuse, interchromatin regions of the nuclei at a stage in rust development (8 days after inoculation) at which two- to three-fold increases in RNA are known to occur. In the late stages of rust development (20 to 23 days after inoculation) the interchromatin material disappeared and the dense chromatin disintegrated.

Sign in / Sign up

Export Citation Format

Share Document