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: 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.

THE PHYSIOLOGY OF HOST–PARASITE RELATIONS: VIII. EFFECTS OF RUST INFECTION ON ASCORBIC ACID ANDGLUTATHIONE IN WHEAT LEAVES

1961 ◽  
Vol 39 (6) ◽  
pp. 1327-1336 ◽  
Author(s):  
B. I. Sahai ◽  
Michael Shaw
Keyword(s):  
Ascorbic Acid ◽  
Puccinia Graminis ◽  
Oxidized Glutathione ◽  
Redox Potentials ◽  
Rust Infection ◽  
Puccinia Graminis Tritici ◽  
Auxin Content ◽  
Wheat Leaves ◽  
Host Parasite

First seedling leaves of Little Club (susceptible), Khapli I (moderately susceptible), and Khapli (resistant) wheats were inoculated with Puccinia graminis tritici Erikss. and Henn. (Race 15B). Ascorbic (AA) and dehydroascorbic (DHA) acids and glutathione (GSH) were measured at 1–2 day intervals after inoculation until after sporulation. After infection, AA and DHA increased in Little Club and decreased in Khapli. In Khapli the DHA/AA ratio rose sharply 6–8 days after inoculation; in Little Club a similar rise occurred 15–16 days after inoculation. In Khapli I and Little Club, but not in Khapli, GSH increased sharply when sporulation occurred. AA was not detected in uredospores, but DHA was. Oxidized glutathione was not detected in healthy or infected leaves but was present in uredospores. The results are discussed briefly in relation to the changes in auxin content and redox potentials caused by rust infection.

THE PHYSIOLOGY OF HOST–PARASITE RELATIONS: XIII. THE EFFECT OF STEM RUST ON PURINES IN WHEAT LEAVES

1964 ◽  
Vol 42 (2) ◽  
pp. 139-144 ◽  
Author(s):  
Michael Shaw ◽  
B. I. Sahai Srivastava
Keyword(s):  
Copper Oxide ◽  
Perchloric Acid ◽  
Stem Rust ◽  
Puccinia Graminis ◽  
Puccinia Graminis Tritici ◽  
Detached Leaves ◽  
Wheat Leaves ◽  
Host Parasite

The purines were precipitated from alcohol extracts of Little Club wheat with copper oxide or absorbed from perchloric acid extracts with Norit A. Guanine, adenine, and an unidentified purine were isolated from seedlings germinated in darkness and from the tops of young plants grown in the greenhouse. Adenine and the unidentified purine were present in much larger amounts than guanine. The concentrations of adenine and the unidentified purine in the first seedling leaves were increased approximately four- and five-fold by infection with Puccinia graminis tritici Erikss. and Henn. No evidence was obtained for the presence of any purine or purine-like substance in uninfected or infected leaves which would delay senescence in detached leaves as do kinetin, benzimidazole, and purine-like substances present in coconut endosperm.

scholarly journals Phenotypes Conferred by Wheat Multiple Pathogen Resistance Locus, Sr2, Include Cell Death in Response to Biotic and Abiotic Stresses

2019 ◽  
Vol 109 (10) ◽  
pp. 1751-1759
Author(s):  
Linda Tabe ◽  
Sharon Samuel ◽  
Matthew Dunn ◽  
Rosemary White ◽  
Rohit Mago ◽  
...  
Keyword(s):  
Cell Death ◽  
Powdery Mildew ◽  
Stem Rust ◽  
Abiotic Stresses ◽  
Resistance Locus ◽  
Petroleum Jelly ◽  
Wheat Stem Rust ◽  
Mesophyll Cells ◽  
Rust Infection ◽  
Photosynthetic Cells

The wheat Sr2 locus confers partial resistance to four biotrophic pathogens: wheat stem rust (Puccinia graminis f. sp. tritici), leaf rust (P. triticina), stripe rust (P. striiformis f. sp. tritici), and powdery mildew (Blumeria graminis f. sp. tritici). In addition, Sr2 is linked with a brown coloration of ears and stems, termed pseudo-black chaff (PBC). PBC, initially believed to be elicited by stem rust infection, was subsequently recognized to occur in the absence of pathogen infection. The current study demonstrates that the resistance response to stem rust is associated with the death of photosynthetic cells around rust infection sites in the inoculated leaf sheath. Similarly, Sr2-dependent resistance to powdery mildew was associated with the death of leaf mesophyll cells around mildew infection sites. We demonstrate that PBC occurring in the absence of pathogen inoculation also corresponds with death and the collapse of photosynthetic cells in the affected parts of stems and ears. In addition, Sr2-dependent necrosis was inducible in leaves by application of petroleum jelly or by heat treatments. Thus, Sr2 was found to be associated with cell death, which could be triggered by either biotic or abiotic stresses. Our results suggest a role for the Sr2 locus in controlling cell death in response to stress.

Haustoria-like branches in axenic cultures of Puccinia graminis f. sp. tritici

1969 ◽  
Vol 47 (11) ◽  
pp. 1816-1817 ◽  
Author(s):  
P. G. Williams
Keyword(s):  
Stem Rust ◽  
Rust Fungus ◽  
Puccinia Graminis ◽  
Wheat Stem Rust ◽  
Artificial Culture ◽  
Axenic Cultures

Hyphae of the wheat stem rust fungus form short, lateral projections under conditions of artificial culture that are unfavorable for saprophytic growth. It is suggested that the structures are homologous with the haustoria of intercellular rust mycelium.

The Constitution of a Glucomannan from Wheat Stem Rust (Puccinia graminis tritici) Urediospores1

1959 ◽  
Vol 81 (3) ◽  
pp. 684-688 ◽  
Author(s):  
N. Prentice ◽  
L. S. Cuendet ◽  
W. F. Geddes ◽  
F. Smith
Keyword(s):  
Stem Rust ◽  
Puccinia Graminis ◽  
Wheat Stem Rust ◽  
Puccinia Graminis Tritici

FORMATION OF TREHALOSE AND POLYOLS BY WHEAT STEM RUST (PUCCINIA GRAMINIS TRITICI) UREDOSPORES

1962 ◽  
Vol 40 (1) ◽  
pp. 1248-1251 ◽  
Author(s):  
H. J. Reisener ◽  
H. R. Goldschmid ◽  
G. A. Ledingham ◽  
A. S. Perlin
Keyword(s):  
Stem Rust ◽  
Puccinia Graminis ◽  
Wheat Stem Rust ◽  
Puccinia Graminis Tritici

Null

Genetics of rust resistance in tetraploid wheats. III. Genes for resistance to stem rust in certain Durum wheats

1967 ◽  
Vol 18 (2) ◽  
pp. 213
Author(s):  
M Ataullah
Keyword(s):  
Stem Rust ◽  
Rust Resistance ◽  
Puccinia Graminis ◽  
Inheritance Of Resistance ◽  
Puccinia Graminis Tritici ◽  
Tetraploid Wheats ◽  
Recessive Genes ◽  
Dominant Genes

The inheritance of resistance to stem rust in four durum wheats, namely P.I.168921, P.I.173401, Gaza, and C.I.7809 was studied. The variety P.I.168921 was found to possess two dominant genes Srt1 and Srt5, P.I.173401 two recessive genes srt6 and srt7, Gaza two dominant genes Srt8 and Srt9, and C.I.7809 genes Srt33 and Srt10, for resistance to Australian strains of Puccinia graminis tritici Erikss. & Henn. It was observed that the genes srt6, srt7, Srt9, and Srt10 were independent of genes already identified. Varieties Khapli, St.464, C.I.7778, and P.I.168921 had gene Srt1Srt1 in common; and varieties St.464, C.I.7778, and C.I.7809 gene Srt3 in common.

THE PHYSIOLOGY OF HOST–PARASITE RELATIONS: VI. OXIDATION–REDUCTION CHANGES IN WHEAT LEAF SAP CAUSED BY RUST INFECTION

1960 ◽  
Vol 38 (3) ◽  
pp. 399-407 ◽  
Author(s):  
Rudolf Kaul ◽  
Michael Shaw
Keyword(s):  
Short Circuit ◽  
Redox Mediators ◽  
Rust Infection ◽  
Reduction Potentials ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Wheat Leaf ◽  
Host Parasite ◽  
Different Levels ◽  
Reduced State

Extracts of healthy and rusted leaves of Little Club and Khapli wheats were made under anaerobic conditions. Oxidation–reduction potentials in the extracts were measured at two different levels both in the presence and in the absence of both methylene blue and riboflavin as redox mediators. At the lower level (i.e. in the absence of mediators) a reversible rise in potential was noted during the course of rust infection on Little Club; with Khapli the rise was similar but was not reversed. The response to rust infection of resistant and susceptible plants was also reflected in characteristic changes in the average potentials at higher levels (i.e. in the presence of mediators). After infection the oxidation–reduction balance of susceptible tissue was reorganized by the introduction of new systems which were found in the reduced state only. After infection the oxidation–reduction potential of resistant tissue was only poorly poised as indicated by a rise in the average potentials and as demonstrated by oxidation– reduction titrations.The results are discussed and the possibility is considered that a rust-induced catalyst may “short circuit” the chain of hydrogen transport, thus initiating all the observed redox changes.

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