THE EFFECT OF VARIOUS METHODS OF BREAKING RESISTANCE ON STEM RUST REACTION AND CONTENT OF SOLUBLE CARBOHYDRATE AND NITROGEN IN WHEAT LEAVES

1958 ◽  
Vol 36 (5) ◽  
pp. 717-723 ◽  
Author(s):  
F. R. Forsyth ◽  
D. J. Samborski
Keyword(s):  
Heat Treatment ◽  
Stem Rust ◽  
Maleic Hydrazide ◽  
Soluble Carbohydrate ◽  
Soluble Nitrogen ◽  
Puccinia Graminis ◽  
Substrate Availability ◽  
Nitrogen Levels ◽  
Carbohydrate Levels ◽  
Wheat Leaves

The resistance of Khapli wheat to a number of races of stem rust, Puccinia graminis (Pers.) f. sp. tritici (Erikss. and Henn.), was broken after treatment with maleic hydrazide, DDT, detaching the leaves, and "searing" (heat treatment at the base of the leaf). In addition, the reaction of several other varieties to a number of races of stem rust was altered from resistant to susceptible by detaching and searing.DDT and searing caused marked increases in carbohydrate and soluble nitrogen levels, while maleic hydrazide caused smaller increases. There were no differences in carbohydrate levels, and only a slight difference in soluble nitrogen, between plants kept at 65° and 75° F., the temperatures at which McMurachy is respectively resistant and susceptible to rust. Insoluble nitrogen decreased after searing and DDT at rates approximately equal to those of the control. Insoluble nitrogen decreased at a faster rate in leaves kept at 75° F. than at 65° F. It remained fairly constant in leaves treated with maleic hydrazide.The data support the concept that substrate availability is of major importance in rust development.

METABOLIC CHANGES IN DETACHED WHEAT LEAVES FLOATED ON BENZIMIDAZOLE AND THE EFFECT OF THESE CHANGES ON RUST REACTION

1958 ◽  
Vol 36 (5) ◽  
pp. 591-601 ◽  
Author(s):  
D. J. Samborski ◽  
F. R. Forsyth ◽  
Clayton Person
Keyword(s):  
Stem Rust ◽  
Metabolic Changes ◽  
Soluble Carbohydrate ◽  
Soluble Nitrogen ◽  
Progressive Decrease ◽  
Detached Leaves ◽  
Endogenous Substrate ◽  
Wheat Leaves

Stem-rust-infected leaves of resistant (var. Khapli) and susceptible (var. Little Club) wheats were detached and floated on water and benzimidazole, with and without glucose. Khapli leaves were susceptible on water, resistant on 40 p.p.m. benzimidazole, susceptible on 40 p.p.m. benzimidazole with 1% glucose, and resistant on 60 p.p.m. benzimidazole with 1% glucose. Little Club leaves were susceptible in all treatments. Khapli leaves subjected to treatments that increase the endogenous substrate levels, such as floating on water for 2 to 4 days or spraying with DDT 2 or 3 days before detachment, were susceptible on 40 p.p.m. benzimidazole and resistant or partially resistant at higher concentrations.The progressive decrease in protein of detached leaves on water was interrupted on transfer to benzimidazole, after which some resynthesis of protein took place with a corresponding decrease in the soluble nitrogen fraction. Detached leaves on benzimidazole with 1% glucose had more soluble nitrogen than leaves on benzimidazole alone. There was more alcohol-soluble carbohydrate in leaves floated on water than in leaves on benzimidazole.

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.

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.

Effect of blasticidin S, ethionine, and polyoxin D on stem rust development and host-cell necrosis in wheat near-isogenic for gene Sr6

1977 ◽  
Vol 55 (5) ◽  
pp. 568-573 ◽  
Author(s):  
W. K. Kim ◽  
R. Rohringer ◽  
D. J. Samborski ◽  
N. K. Howes
Keyword(s):  
Host Cell ◽  
Stem Rust ◽  
Fungal Growth ◽  
Triticum Aestivum L ◽  
Hypersensitive Reaction ◽  
Host Cells ◽  
Puccinia Graminis ◽  
Cell Necrosis ◽  
Blasticidin S ◽  
Wheat Leaves

Seedlings of resistant (Sr6) and susceptible (sr6) near-isogenic lines of wheat (Triticum aestivum L.) were inoculated with an avirulent (P6) race of stem rust (Puccinia graminis (Pers.) f.sp. tritici Eriks. & Henn.) and kept for 2 days at 26 °C where the Sr6 gene is ineffective, treated with blasticidin S, ethionine, polyoxin D, or buffer, and transferred to 19 °C where the Sr6 gene is normally effective. One and 2 days later, leaves were stained with Calcofluor and examined by fluorescence microscopy to detect autofluorescing necrotic host cells and Calcofluor-stained stem rust colonies.Blasticidin S was phytotoxic to wheat leaves at concentrations that had no effect on fungal growth during the first 2 days after treatment. At later stages, extensive host necrosis, resulting from the phytotoxicity of this antibiotic, inhibited rust development.Ethionine and polyoxin D strongly inhibited rust development at concentrations that were not phytotoxic. In genotypically resistant leaves treated with ethionine and polyoxin D there were fewer necrotic cells associated with stem rust colonies than in leaves treated with buffer. The spacial distribution of necrotic cells was consistent with the view that necrosis occurs only in cells newly invaded after the temperature was lowered to 19 °C.The observations do not support the concept that host-cell necrosis in the hypersensitive reaction conditioned by this gene results from the death of the fungus.

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.

Histological studies on host-cell necrosis conditioned by the Sr6 gene for resistance in wheat to stem rust

1977 ◽  
Vol 55 (11) ◽  
pp. 1445-1452 ◽  
Author(s):  
D. J. Samborski ◽  
W. K. Kim ◽  
R. Rohringer ◽  
N. K. Howes ◽  
R. J. Baker
Keyword(s):  
Triticum Aestivum ◽  
Stem Rust ◽  
Fungal Growth ◽  
Triticum Aestivum L ◽  
Host Cells ◽  
Puccinia Graminis ◽  
Near Isogenic Lines ◽  
Cell Necrosis ◽  
Calcofluor White ◽  
Histological Studies

Seedlings of resistant (Sr6) and susceptible (sr6) near-isogenic lines of wheat (Triticum aestivum L.) were inoculated with a race of stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. & E. Henn.) that was avirulent on the line with Sr6 and they were kept at 19, 25, 26, and 27 °C. Fluorescence microscopy was used to detect autofluorescing necrotic host cells and rust colonies after these were stained with a fiuorochrome (Calcofluor White M2R New).In leaves containing the Sr6 gene, a smaller percentage of colonies grown at 25 °C had necrotic cells associated with them than those that were grown at 19 °C. The incidence of colony-associated necrosis in these leaves could be further reduced by increasing the temperature to 26 °C and 27 °C. Similarly, the number of necrotic host cells per colony decreased with an increase in temperature. Colonies in genotypically resistant leaves were usually smaller than those in genotypically susceptible leaves, but the differences in colony sizes between these two lines decreased at the higher temperatures.When infected plants containing the Sr6 gene were kept for varying times at 25 °C and then were transferred to 19 °C, there was significantly less fungal growth and more necrosis than in plants kept continuously at 25 °C. This necrosis occurred largely in those cells that were invaded after the transfer to 19 °C, when the Sr6 gene was activated.

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

1967 ◽  
Vol 45 (11) ◽  
pp. 2137-2153 ◽  
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.

scholarly journals Seedling Stage Resistance of Iranian Bread Wheat Germplasm to Race Ug99 of Puccinia graminis f. sp. tritici

Plant Disease ◽  
2013 ◽  
Vol 97 (3) ◽  
pp. 387-392 ◽  
Author(s):  
Mohsen Mohammadi ◽  
Davoud Torkamaneh ◽  
Mehran Patpour
Keyword(s):  
Resistance Genes ◽  
Stem Rust ◽  
Rust Resistance ◽  
Stem Rust Resistance ◽  
Puccinia Graminis ◽  
Wheat Cultivars ◽  
Breeding Lines ◽  
Wheat Germplasm ◽  
Stem Rust Resistance Genes ◽  
Rust Resistance Genes

Following emergence of Ug99, the new virulent race of Puccinia graminis f. sp. tritici in Africa, a global effort for identification and utilization of new sources of Ug99-resistant germplasm has been undertaken. In this study, we conducted replicated experiments to evaluate the resistance of Iranian wheat germplasm to the TTKSK lineage of the Ug99 race of P. graminis f. sp. tritici. We also evaluated for presence of stem rust resistance genes (i.e., Sr2, Sr24, Sr26, Sr38, Sr39, Sr31, and Sr1RSAmigo) in wheat cultivars and breeding lines widely cultivated in Iran. Our phenotyping data revealed high levels of susceptibility to Ug99 in Iranian bread wheat germplasm. Our genotyping data revealed that Iranian cultivars do not carry Sr24, Sr26, or Sr1RSAmigo. Only a few salt-tolerant cultivars and breeding lines tested positively for Sr2, Sr31, Sr38, or Sr39 markers. In conclusion, the genetic basis for resistance to Ug99 in Iranian wheat cultivars was found to be vulnerable. Acquiring knowledge about existing resistance genes and haplotypes in wheat cultivars and breeding lines will help breeders, cereal pathologists, and policy makers to select and pyramid effective stem rust resistance genes.

Influence of environmental conditions on insect reproduction and chemical composition of escamoles (Liometopum apiculatum M)

2016 ◽  
Vol 2 (1) ◽  
pp. 61-65 ◽  
Author(s):  
V. Melo-Ruíz ◽  
K. Sánchez-Herrera ◽  
H. Sandoval-Trujillo ◽  
R. Díaz-García ◽  
T. Quirino-Barreda
Keyword(s):  
Nutritional Value ◽  
Nutritional Condition ◽  
Soluble Carbohydrates ◽  
Soluble Carbohydrate ◽  
Arid Zones ◽  
Good Source ◽  
Rural People ◽  
Abiotic Conditions ◽  
Carbohydrate Levels ◽  
Insect Reproduction

Escamoles, ant eggs (Liometopum apiculatum M), are edible insects consumed in great numbers and appreciated for their sensory characteristics, but not for their nutritional value. In Mexico, they reproduce in arid and semi-arid zones of Mexico and several states (Puebla, Tlaxcala, Hidalgo). Samples were gathered to determine reproduction conditions and perform an insect analysis to generate data composition in macronutrients, on dry basis, according to AOAC methods. The obtained data were: proteins: 42.12-50.63%; lipids: 30.27-34.96%; minerals: 6.53-7.85%; fibres: 1.91-2.56%; and soluble carbohydrates: 6.80-18.27%. Entomological material was collected in spring 2014, 3 nests for each zone, all from different altitudes and agroclimatic regions. Samples were representative for the insect supply in the areas studied. Insects are high in proteins and lipids, compared with most of the commonly consumed food, due to their high content of fatty acids; they must be refrigerated for later consumption. Minerals are moderated. Fibre and soluble carbohydrate levels are low, but an excess of proteins can be converted into carbohydrates via gluconeogenesis. Escamoles reproduce once a year in the spring, but sometimes one nest can provide escamoles eggs twice in the same season, once at the beginning and again at the end, depending on the biotic and abiotic conditions of their environment. Escamoles are a good source of nutrients; however, some rural people sell them to obtain extra income rather than consume them to improve their nutritional condition and welfare.

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