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

1970 ◽  
Vol 48 (4) ◽  
pp. 803-811 ◽  
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.

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.

THE PHYSIOLOGY OF HOST–PARASITE RELATIONS: VII. THE EFFECT OF STEM RUST ON THE NITROGEN AND AMINO ACIDS IN WHEAT LEAVES

1961 ◽  
Vol 39 (6) ◽  
pp. 1351-1372 ◽  
Author(s):  
Michael Shaw ◽  
Nicholas Colotelo
Keyword(s):  
Amino Acids ◽  
Stem Rust ◽  
Dry Weight ◽  
Aminobutyric Acid ◽  
Fresh Weight ◽  
Total N ◽  
Fourfold Increase ◽  
Barley Leaves ◽  
Protein Amino Acids ◽  
Wheat Leaves

The dry weight of leaf disks (2.8 mm in diameter) bearing pustules of stem rust and cut from primary leaves of Little Club wheat increased up to 2.5-fold, but the respective weights of host and parasite cannot be measured. By removal of the ectoparasitic mycelium of Erysiphe it was shown that approximately half of the increase in weight at infections of this organism on barley leaves was contributed by the fungus and half by the host.At infections of stem rust on Little Club there was a striking increase in total N per gram fresh weight and an increase in the ratio of soluble to insoluble N. Quantitative paper chromatographic analyses revealed a fourfold increase in free amino acids and nearly a twofold increase in protein amino acids per gram fresh weight by 9 days after inoculation. The most striking increases occurred in free glutamine, γ-aminobutyric acid, threonine, and those amino acids present only in trace amounts before inoculation, particularly the basic and aromatic acids. Only slight and transitory increases in N occurred at infections on Khapli and the infected leaves quickly reached a stage at which soluble and insoluble N and the ratios of soluble N to insoluble N and free to protein amino acids declined drastically. In Khapli, well-defined increases occurred in free glutamine and γ-aminobutyric acid. Particularly striking decreases occurred in glutamate, serine, threonine, glycine, and the leucines. The results are discussed.

METABOLISM OF AROMATIC COMPOUNDS IN HEALTHY AND RUST-INFECTED PRIMARY LEAVES OF WHEAT: I. STUDIES WITH 14CO2, QUINATE-U-14C, AND SHIKIMATE-U-14C AS PRECURSORS

1967 ◽  
Vol 45 (6) ◽  
pp. 863-889 ◽  
Author(s):  
R. Rohringer ◽  
A. Fuchs ◽  
J. Lunderstädt ◽  
D. J. Samborski
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Stem Rust ◽  
Aromatic Compounds ◽  
Alternative Pathway ◽  
Aromatic Amino Acids ◽  
Insoluble Residue ◽  
Near Isogenic Lines ◽  
Acid Fraction ◽  
Wheat Leaves

Healthy and stem rust infected leaves of two near-isogenic lines of wheat were allowed to metabolize 14CO2, quinate-U-14C, or shikimate-U-14C for 22 h in the light.Quinate-U-14C and shikimate-U-14C were interconvertible but differed in their efficiency as precursors of phenylalanine and tyrosine, suggesting that an alternative pathway, not via shikimate, exists from quinate to phenylalanine in wheat leaves. Activity from the cyclites was not incorporated into tryptophan during the metabolic period. Evidently, synthesis of aromatic amino acids in wheat leaves is not restricted to the "classic" shikimate pathway.Infection with rust led to an increase of the carbon How from CO2 to shikimate and to higher levels of both quinate and shikimate. This trend was more pronounced in susceptible than in resistant leaves. Moreover, utilization of quinate and shikimate was increased in infected susceptible leaves but was not altered significantly in infected resistant leaves. Resistant and susceptible reacting leaves differed in the distribution of activity derived from quinate-U-14C and shikiniate-U-14C. With shikimate-U-14C as precursor, resistant reacting leaves accumulated activity in unidentified components of the amino acid fraction (Amberlite IR-120 eluate). Susceptible reacting leaves accumulated less activity in these compounds, and healthy leaves contained only traces of activity in them. When either quinate-U-14C or shikimate-U-14C was metabolized by healthy leaves, more activity was recovered in insoluble esters (of ferulate and p-coumarate) than in soluble esters. Resistant reacting leaves accumulated still more activity in the insoluble esters, whereas susceptible reacting leaves contained a proportionately higher amount of activity in soluble esters. Compared with healthy leaves, susceptible reacting leaves always contained less activity, and resistant reacting leaves more activity, in the non-hydrolyzable, insoluble residue.

Prebiotic synthesis of carboxylic acids, amino acids and nucleic acid bases from formamide under photochemical conditions⋆

2017 ◽  
Vol 132 (7) ◽  
Author(s):  
Lorenzo Botta ◽  
Bruno Mattia Bizzarri ◽  
Davide Piccinino ◽  
Teresa Fornaro ◽  
John Robert Brucato ◽  
...  
Keyword(s):  
Amino Acids ◽  
Nucleic Acid ◽  
Carboxylic Acids ◽  
Prebiotic Synthesis ◽  
Nucleic Acid Bases

CHLOROPHYLL, PROTEIN, AND NUCLEIC ACID LEVELS IN DETACHED, SENESCING WHEAT LEAVES

1965 ◽  
Vol 43 (6) ◽  
pp. 739-746 ◽  
Author(s):  
Michael Shaw ◽  
P. K. Bhattacharya ◽  
W. A. Quick
Keyword(s):  
Nucleic Acid ◽  
Oxygen Uptake ◽  
Nucleic Acids ◽  
Nuclear Protein ◽  
Fresh Weight ◽  
Rapid Loss ◽  
Nuclear Rna ◽  
Chlorophyll Protein ◽  
Chloroplast Rna ◽  
Wheat Leaves

Excised primary leaves of Little Club and Khapli wheats were allowed to senesce on water or on kinetin (10 mg/l.) for 6 to 8 days. Histological sections taken at 2-day intervals were stained for RNA, DNA, histone, and total protein. Twenty-five or thirty leaves were analyzed daily for chlorophyll, protein, and nucleic acids. Oxygen uptake was also measured. Examination of the sections showed that leaves senescing on water underwent rapid losses in chloroplast RNA and protein and in nuclear RNA. Losses in DNA, histone, and total nuclear protein were delayed until the nuclei disintegrated. These observations are correlated with the analytical results. The latter revealed statistically significant losses in chlorophyll, protein, and nucleic acid contents with time. The losses in nucleic acids were due mainly, if not entirely, to losses in RNA. Oxygen uptake per gram fresh weight in the leaves on water did not change significantly with days after excision. Kinetin significantly delayed losses in chlorophyll, RNA, and protein, and depressed oxygen uptake. Certain differences between the two varieties of wheat are described, including the more rapid loss of nucleic acid in Khapli.

Pathotype Identification and Virulence Variation in Cochliobolus sativus in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Lin Chen ◽  
Quanjie Yao ◽  
Fengtao Wang ◽  
Yunxing Pang ◽  
Xiaowei Lang ◽  
...  
Keyword(s):  
Regional Climate ◽  
Cochliobolus Sativus ◽  
Wheat Varieties ◽  
Geographic Origins ◽  
High Virulence ◽  
Wheat Leaves ◽  
Barley Genotypes ◽  
Important Disease ◽  
Wheat Tissues ◽  
Virulence Variation

Spot blotch caused by Cochliobolus sativus has become an important disease in the wheat-growing regions in China due to changes of regional climate, agricultural cultivation pattern and widely growing susceptible wheat varieties. Little information is available about virulence variability and pathogenic specialization of the C. sativus isolates from major wheat-growing regions in China. Here, 12 representative wheat varieties and foundation breeding stocks were selected to characterize the pathotypes of C. sativus isolates from infected wheat plants. Based on the infection phenotypes in the 12 differential genotypes at the seedling stage, 70 Chinese pathotypes were identified from 110 isolates and clustered into three virulence groups. The high virulence isolates were collected from wheat leaves, crowns, and roots, with most (10 of 14) from the Henan province in the Huang-Huai plain. No relationship was evident between virulence variability of C. sativus isolates and their geographic origins or types of diseased wheat tissues. Cochliobolus sativus showed a significant pathogenic specialization in hosts of wheat and barley. Most of the wheat isolates (50 of 65) were avirulent to all the differential barley genotypes, and a few were virulent only to highly susceptible barley genotypes. These results indicated that C. sativus isolates from the wheat-growing regions in China varied considerably for their virulence in wheat varieties, and showed significant pathogenic specialization to the wheat and barley hosts.

A Fungal Elicitor of the Resistance Response in Wheat

1985 ◽  
Vol 40 (9-10) ◽  
pp. 743-744 ◽  
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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