Peroxidase isoenzyme patterns of resistant and susceptible wheat leaves following stem rust infection

The soluble proteins of wheat leaf and of stem rust uredospores were resolved into about 28 and 34 components, respectively, by disk electrophoresis. The funguscontaining and the fungus-free areas of infected wheat leaves were examined. The electrophoretic pattern of an extract of the lesions was markedly different from the pattern of an extract of uninfected leaves. Comparison with the pattern of an extract of uredospores suggested that some of these differences were due to contamination with fungal proteins. For susceptible varieties, extracts of the extralesion areas of infected leaves showed different electrophoretic patterns from extracts of uninfected leaves. This was not so for resistant wheat varieties.

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METABOLISM OF AROMATIC COMPOUNDS IN HEALTHY AND RUST-INFECTED PRIMARY LEAVES OF WHEAT: II. STUDIES WITH L-PHENYLALANINE-U-14C, L-TYROSINE-U-14C, AND FERULATE-U-14C

Canadian Journal of Botany ◽

10.1139/b67-233 ◽

1967 ◽

Vol 45 (11) ◽

pp. 2137-2153 ◽

Cited By ~ 23

Author(s):

A. Fuchs ◽

R. Rohringer ◽

D. J. Samborski

Keyword(s):

Amino Acids ◽

Stem Rust ◽

Aromatic Compounds ◽

The Other ◽

Major Portion ◽

Insoluble Residue ◽

Resistant Reaction ◽

Wheat Leaves

Wheat leaves infected with stem rust, especially those of susceptible plants, contained more phenylalanine and tyrosine than healthy leaves. The utilization of phenylalanine was increased in both the susceptible and resistant reaction, but the utilization of tyrosine was increased only in the susceptible reaction. No evidence of interconversion of these amino acids was obtained.In n-butanol extracts, which contained glycosides, many constituents were labelled after feeding of L-phenylalanine-U-14C. Most of the n-butanol extractives from resistant-reacting leaves contained more label than those from susceptible-reacting leaves or from healthy leaves. However, one of the n-butanol extractives from susceptible-reacting leaves was 5–10 times as active as that isolated from the other tissues.With L-phenylalanine-U-14C and ferulate-U-14C as precursors, more activity was recovered in insoluble than in soluble esters (of ferulate and p-coumarate). With L-tyrosine-U-14C as precursor, the reverse was observed. After infection, the proportion of label in insoluble esters increased more in resistant leaves than it did in susceptible leaves, regardless of the precursor used.A major portion of the activity from these precursors was recovered in the insoluble residue that contained protein and other polymers. In the experiment with L-phenylalanine-U-14C, this residue was fractionated into protein and non-hydrolyzable material. Susceptible-reacting leaves contained equal amounts of activity in these fractions, while resistant-reacting leaves incorporated 2.5 times as much activity into the non-hydrolyzable material as into protein.

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Effect of Rust Infection on Oxidative Phosphorylation of Wheat Leaves

Nature ◽

10.1038/1821686a0 ◽

1958 ◽

Vol 182 (4650) ◽

pp. 1686-1687 ◽

Cited By ~ 16

Author(s):

B. I. POZSÁR ◽

Z. KIRÁLY

Keyword(s):

Oxidative Phosphorylation ◽

Rust Infection ◽

Wheat Leaves

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

Phytopathology ◽

10.1094/phyto-03-19-0099-r ◽

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.

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A Fungal Elicitor of the Resistance Response in Wheat

Zeitschrift für Naturforschung C ◽

10.1515/znc-1985-9-1028 ◽

1985 ◽

Vol 40 (9-10) ◽

pp. 743-744 ◽

Cited By ~ 11

Author(s):

Karl-Heinz Kogel ◽

Birgit Heck ◽

Gerd Kogel ◽

Bruno Moerschbacher ◽

Hans-Joachim Reisener

Keyword(s):

Stem Rust ◽

Active Compound ◽

Germ Tube ◽

Phenylpropanoid Pathway ◽

Metabolic Changes ◽

Fungal Elicitor ◽

Wheat Stem Rust ◽

Mesophyll Cells ◽

Resistance Response ◽

Wheat Leaves

Abstract An elicitor of the lignification response in wheat leaves was isolated from the germ-tube walls of wheat stem rust. The active compound causes metabolic changes typically correlated with the resistance response, i.e. the formation of lignin or lignin-like polymers in affected epidermal and mesophyll cells and the increased activities of enzymes involved in the phenylpropanoid-pathway.

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Fraction I Protein in Wheat Leaves Infected with Stem Rust

Biochemical Society Transactions ◽

10.1042/bst0020121 ◽

1974 ◽

Vol 2 (1) ◽

pp. 121-123

Author(s):

JOHN BENNETT ◽

KENNETH J. SCOTT

Keyword(s):

Stem Rust ◽

Fraction I Protein ◽

Wheat Leaves ◽

Fraction I

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Formate metabolism and betaine formation in healthy and rust-infected wheat

Canadian Journal of Botany ◽

10.1139/b70-110 ◽

1970 ◽

Vol 48 (4) ◽

pp. 803-811 ◽

Cited By ~ 17

Author(s):

Margaret S. Bowman ◽

R. Rohringer

Keyword(s):

Amino Acids ◽

Nucleic Acid ◽

Stem Rust ◽

Betaine Lipids ◽

Dark Metabolism ◽

Synthesis Activity ◽

C Metabolism ◽

Wheat Leaves ◽

Wheat Tissues ◽

Formate Metabolism

Formate-14C was fed to detached primary leaves of wheat and the distribution of activity among various fractions was examined after 2 to 26 h of metabolism in the light or 4 h of metabolism in the dark.All samples contained activity in free neutral, acidic, and basic compounds. The radioactive metabolites in the basic fraction were examined in detail. Initially, in the light, glutamate, aspartate, serine, and an unknown, chromatographically similar to, but not identical with histidine, contained most of the activity. Activity in betaine increased with time until, at 26 h, it contained nearly half of the activity in this fraction. Following dark metabolism, most of the activity resided in glutamate and serine. Glycine was not radioactive, and most of the activity in serine resided in carbon 3, indicating that formate served as a precursor of C1-units that were used for serine synthesis. Activity was also detected in a number of other amino acids and choline, both in the light and dark.A comparison of formate-14C metabolism in the dark in stem rust resistant and susceptible wheat leaves revealed that betaine, lipids, nucleic acid bound adenine and guanine, and a protein-containing residue from rust-infected susceptible leaves contained much more activity than the corresponding components from healthy susceptible or from healthy or rust-infected resistant leaves.Activity from glycine-2-3H, methionine-14CH3, serine-3-14C, ethanolamine-1,2-14C, and choline-14CH3 was incorporated into betaine in the dark, but was not detected in sarcosine or dimethylglycine. These results support the view that betaine was synthesized from glycine via serine, ethanolamine, and choline with methionine as the methyl donor, and not by direct N-methylation of glycine.Betaine-14CH3 was translocated but not metabolized in healthy or rust-infected primary leaves of wheat, or in aerial portions of adult wheat plants. In these wheat tissues, betaine would thus appear to be a metabolic end product.

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Soluble carbohydrates and invertase activity in stem rust-infected, resistant and susceptible near-isogenic wheat leaves

Physiological and Molecular Plant Pathology ◽

10.1016/s0885-5765(05)80070-0 ◽

1994 ◽

Vol 45 (2) ◽

pp. 111-123 ◽

Cited By ~ 22

Author(s):

D. Heisterüber ◽

P. Schulte ◽

B.M. Moerschbacher

Keyword(s):

Stem Rust ◽

Invertase Activity ◽

Soluble Carbohydrates ◽

Wheat Leaves

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Evaluating ten spectral vegetation indices for identifying rust infection in individual wheat leaves

Precision Agriculture ◽

10.1007/s11119-008-9100-2 ◽

2008 ◽

Vol 10 (6) ◽

pp. 459-470 ◽

Cited By ~ 110

Author(s):

R. Devadas ◽

D. W. Lamb ◽

S. Simpfendorfer ◽

D. Backhouse

Keyword(s):

Vegetation Indices ◽

Rust Infection ◽

Spectral Vegetation Indices ◽

Wheat Leaves

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Sterols of healthy and rust-infected primary leaves of wheat and of non-germinated and germinated uredospores of wheat stem rust

Canadian Journal of Botany ◽

10.1139/b72-024 ◽

1972 ◽

Vol 50 (1) ◽

pp. 185-190 ◽

Cited By ~ 24

Author(s):

R. Nowak ◽

W. K. Kim ◽

R. Rohringer

Keyword(s):

Thin Layer ◽

Stem Rust ◽

Total Sterol ◽

Sterol Content ◽

Wheat Stem Rust ◽

Resistant Lines ◽

Wheat Leaves

Sterols extracted from healthy and rust-infected primary leaves of wheat or from non-germinated and germinated uredospores of stem rust were analyzed by thin-layer, column, and gas–liquid chromatography.Wheat leaves of susceptible and resistant lines contained cholesterol, campesterol, stigmasterol, β-sitosterol, and an unknown sterol that accounted for 75% to 80% of total sterol content. A further sterol, stigmast-7-enol, occurred in all rust-infected leaves and in 1 of 11 samples of healthy leaves. Sterol levels were not related to susceptibility or resistance. The level of stigmast-7-enol in infected leaves appeared to be correlated with the amount of fungal mass in the host.Uredospores of stem rust contained trace amounts of an unknown sterol, cholesterol, and either ergost-7-enol or stigmasterol, and larger amounts of stigmast-7-enol. After germination, the level of cholesterol increased, especially in differentiating uredosporelings. The level of stigmast-7-enol tended to decrease after germination.Sterol fractions from wheat leaves (healthy and rust-infected) and from stem rust uredospores (non-germinated and germinated) were not phytotoxic. They did not inhibit rust development in susceptible leaves nor did they promote it in resistant leaves.

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