MESURE DE L’ENDURCISSEMENT AU FROID ET DE LA VIABILITE DES PLANTES EXPOSEES AU GEL PAR LE DOSAGE DES PHOSPHATASES ACIDES LIBRES

1978 ◽  
Vol 58 (4) ◽  
pp. 1007-1018 ◽  
Author(s):  
R. BOLDUC ◽  
L. RANCOURT ◽  
P. DOLBEC ◽  
L. CHOUINARD-LAVOIE
Keyword(s):  
Triticum Aestivum ◽  
Phosphatase Activity ◽  
Cell Walls ◽  
Cold Hardiness ◽  
External Medium ◽  
Freezing Point ◽  
Activity Index ◽  
Triticum Aestivum L ◽  
Freezing Test ◽  
The One

Cellular freezing induces leaking of non-specific acid phosphatase enzymes (EC. 3.1.3.2) from the cell walls of wheat crowns into the liquid medium surrounding the plant tissues. Those free enzymes leak both in the disorganized cytoplasm and in the external medium surrounding the tissues. The phosphastase activity index, measured in the external medium of the frozen plants as compared with the one of the non-frozen plants, decreases proportionally with the temperature of the freezing test until a minimum plateau is reached corresponding to the killing temperature of the plants. The determination of this phosphatase activity index can be used therefore as a quantitative method for the estimation of the viability of plants exposed to freezing. The initial drop of the phosphatase activity index precedes the viability loss as measured with the regrowth tests. The solubilization of those acid phosphatases previously bonded to the cell walls is one cause of the plant death rather than its consequence. The differentiating degrees of cold hardiness can be calculated from the changes in the phosphatase activity during a programmed freezing test among cultivars or species, immediately after running the test. Kharkov (Triticum aestivum L.) sampled in the fall shows + 13 °C differential of cold hardiness as compared with the one sampled in summer while Champlein (Triticum aestivum L.) has developed + 5 °C differential of cold hardiness. In the same conditions, another species (Medicago sativa L. cv. Saranac) shows − 9 °C differential of cold hardiness as compared with Kharkov. Temperatures near the freezing point stabilize instantly the attachment of enzymes to cell walls. This molecular rearrangement, at the enzymatic level, is related to the initial metabolism of cold hardening.

INTERACTION BETWEEN SILICON AND ALUMINUM IN TRITICUM AESTIVUM L. (CV. CELTIC)

1997 ◽  
Vol 45 (4) ◽  
pp. 285-292 ◽  
Author(s):  
Kay M. Cocker ◽  
Martin J. Hodson ◽  
David E. Evans ◽  
Allan G. Sangster
Keyword(s):  
Triticum Aestivum ◽  
Continuous Flow ◽  
Cell Walls ◽  
Dry Weight ◽  
Triticum Aestivum L ◽  
Test Solution ◽  
Root Tip ◽  
Solution Ph ◽  
Al Content ◽  
Al Treatment

Seedlings ofTriticum aestivumL. (cv. Celtic) were suspended in plastic tubs containing 500 μmol L−1Ca(NO3)2and 31 μmol L−1KC1 as background solution. A1C13(0 and 100 μmol L−1) and Na2SiO3.5H2O (0 and 2000 μmol; L−1) were added to this basal nutrient medium, and solution pH was set at 4.2 or 4.6. Tubs were aerated and supplied with a continuous flow of pH-adjusted test solution. Plants were grown for 4 d in a growth cabinet at 25 °C with a 16 h photoperiod. At pH 4.2 and 4.6 root length of the seedlings was inhibited at 100 μmol L−1Al. An amelioration of Al-induced toxicity symptoms was observed in the 100 μmol L−1A1/2000 μmol L−1Si treatment at pH 4.6, but not at pH 4.2. Both the shoot (S) and root (R) dry weight of seedlings treated with 100 μmol L−1Al were reduced when compared with controls. Treatment with Al increased S:R ratios, and this effect was ameliorated by Si, but only at pH 4.6.Al content of roots treated with 100 μmol L−1Al or 100 μmol L−1Al/2000 μmol L−1Si increased significantly when compared with controls. More Al accumulated in the roots of seedlings of the 100 μmol L−1Al/2000 μmol L−1Si treatment than in the 100 μmol L−1treatment. Al treatment reduced root and shoot K concentrations under both pH regimes, and Si did not ameliorate this effect. Al treatment had little effect on seedling Ca levels.Three treatments were selected for a microanalytical investigation of the basal third of the root, and the zone 3.5 mm behind the root tip: 2800 μmol L−1Si; 75 μmol Al; and a combination of the two. When plants were grown in 2800 μmol L−1Si the major silica deposition sites in the roots were the endodermal walls. In the 75 μmol L−1Al treatment, Al was mainly located in the epidermal and hypodermal walls. Al treatment caused a leakage of phosphorus into these cell walls. When both 2800 μmol L−1and 75 μmol L−1Al were present in the nutrient solution, only Si was deposited in the endodermal walls, while both elements were present in the epidermal walls. Leakage of phosphorus appeared to be prevented in the presence of Si.

Differences in endosperm cell wall integrity in wheat (Triticum aestivum L.) milling fractions impact on the way starch responds to gelatinization and pasting treatments and its subsequent enzymatic in vitro digestibility

2019 ◽  
Vol 10 (8) ◽  
pp. 4674-4684 ◽  
Author(s):  
Konstantinos Korompokis ◽  
Niels De Brier ◽  
Jan A. Delcour
Keyword(s):  
Triticum Aestivum ◽  
Cell Wall ◽  
Cell Walls ◽  
Triticum Aestivum L ◽  
Cell Wall Integrity ◽  
In Vitro Digestibility ◽  
Endosperm Cell ◽  
Amylolytic Enzymes ◽  
Physical Barriers

Intact wheat endosperm cell walls reduce intracellular starch swelling and retard its in vitro digestion by acting as physical barriers to amylolytic enzymes.

EFFECT OF PHENOXY HERBICIDES ON COLD HARDINESS OF WINTER WHEAT

1979 ◽  
Vol 59 (1) ◽  
pp. 237-240 ◽  
Author(s):  
S. FREYMAN ◽  
W. M. HAMMAN
Keyword(s):  
Winter Wheat ◽  
Cold Hardiness ◽  
Triticum Aestivum L ◽  
Controlled Environment ◽  
Minor Effect ◽  
Active Growth ◽  
Phenoxy Herbicides ◽  
Freezing Test ◽  
Environment Experiment ◽  
A Minor

In a controlled environment experiment, five phenoxy herbicides were sprayed at two rates on 14-day-old winter wheat (Triticum aestivum L. emend Thell ’Norstar’). After 7 additional days of active growth, the plants were cold-hardened for 14 days and then subjected to a freezing test. Four of the herbicides — MCPA amine, 2,4-D ester, 2,4-DB, 2,4-D amine — significantly reduced the cold hardiness of winter wheat whereas diclofop methyl had a minor effect. The reduction in hardiness was greater at the higher rates of application than at the lower rates.

EFFECT OF A Rht GENE CONDITIONING THE SEMIDWARF CHARACTER ON WINTERHARDINESS IN WINTER WHEAT (Triticum aestivum L. em Thell)

1988 ◽  
Vol 68 (2) ◽  
pp. 301-309 ◽  
Author(s):  
D. J. GILLILAND ◽  
D. B. FOWLER
Keyword(s):  
Triticum Aestivum ◽  
Gibberellic Acid ◽  
Winter Wheat ◽  
Great Plains ◽  
Cold Hardiness ◽  
Triticum Aestivum L ◽  
Breeding Strategy ◽  
Sensitivity Analyses ◽  
Wheat Cultivars ◽  
Winter Wheat Cultivars

In the northern part of the North American Great Plains, the level of cultivar winter-hardiness required for winter wheat (Triticum aestivum L.) production is extremely high. Presently, available winter wheat cultivars with adequate winterhardiness are tall and, under favourable growing conditions, crop lodging and excessive amounts of straw can present serious production problems. Consequently, cultivars with short, stiff straw and a high harvest index would be desirable for high production areas within this region. However, semidwarf cultivars with superior winterhardiness have not yet been developed. In this study, six GA-insensitive (Rht) semidwarf parents with poor to moderate winterhardiness were crossed with three GA-sensitive (rht) tall parents possessing good winterhardiness to produce 20 different single, three-way and double crosses. These crosses were evaluated to determine if the GA-insensitive character could be combined with a high level of winterhardiness in winter wheat. Gibberellic acid (GA) sensitivity analyses of F2 seedlings established that a single GA-insensitive gene was involved in each cross. F2-derived F3 and F3-derived F4 lines were assessed for GA-sensitivity and winterhardiness levels were determined from field survival at several locations in Saskatchewan, Canada. Winter survival of homozygous GA-sensitive and GA-insensitive lines were similar in both generations. Lines with winterhardiness levels similar to those of the three tall parent cultivars were recovered in all GA-response classes. The absence of a meaningful pleiotropic effect of Rht genes on winterhardiness indicates that the reason semidwarf cultivars with superior winterhardiness levels have not been developed is due to the lack of a concentrated breeding effort to combine the two characters. A breeding strategy for the production of adapted winterhardy semidwarf winter wheat cultivars is discussed. The influence of endogenous gibberellin levels on cold hardiness in winter wheat is also considered.Key words: Cold hardiness, field survival, Triticum aestivum L, semidwarf, Gibberellic acid

THE EFFECT OF LONG EXPOSURE TO LOW TEMPERATURES ON THE COLD HARDINESS OF SPROUTING WHEAT IN THE DARK

1985 ◽  
Vol 65 (4) ◽  
pp. 893-900 ◽  
Author(s):  
D. W. A. ROBERTS
Keyword(s):  
Triticum Aestivum ◽  
Low Temperatures ◽  
Cold Hardiness ◽  
Triticum Aestivum L ◽  
Late Winter ◽  
Initial Increase ◽  
Winter Mortality ◽  
Canadian Prairies ◽  
Northern Regions ◽  
Cold Hardy

Nine cultivars of common wheat (Triticum aestivum L.) ranging from very cold hardy to tender were sprouted in vermiculite at 0.5–1.0 °C for 7 wk in the dark and then placed at 0.5 °C, −2.5 °C, −5 °C, −7.5 °C, or −10 °C for up to 20 wk. Plants held at 0.5 °C progressively lost hardiness. Little change occurred in the hardiness of plants moved to −2.5 °C. There was apparently a small initial increase in hardiness after transfer to −5 °C or −7.5 °C followed by a decline in hardiness. Plants transferred to −10 °C lost hardiness progressively after transfer. These results suggest that part of the reason for late-winter mortality of winter wheats in northern regions of the Canadian prairies is damage from long exposures to temperatures only slightly lower than −5 °C. This damage is manifested by higher LT50 values or lower cold hardiness in late winter and early spring.Key words: Triticum aestivum L., cold hardiness, winter survival

INFLUENCE OF DURATION OF GROWTH, SEED SIZE, AND SEEDING DEPTH ON COLD HARDINESS OF TWO HARDY WINTER WHEAT CULTIVARS

1978 ◽  
Vol 58 (4) ◽  
pp. 917-921 ◽  
Author(s):  
S. FREYMAN
Keyword(s):  
Winter Wheat ◽  
Cold Hardiness ◽  
Marked Effect ◽  
Dry Weight ◽  
Triticum Aestivum L ◽  
Controlled Environment ◽  
Small Seed ◽  
Winter Wheat Cultivars ◽  
Freezing Test ◽  
Test Plants

Two winter wheat (Triticum aestivum L.) cultivars, Kharkov 22 MC and Winalta, were grown for 14 or 28 days under controlled environment from large or small seed or from seed with about half the endosperm removed. The kernels were seeded either 1 or 5 cm deep. After a 14-day cold hardening period followed by a freezing test, plants that had grown actively for 28 days were hardier than those that had grown actively for only 14 days. Plants from large kernels were hardier than those from small kernels, which in turn were slightly hardier than those from kernels with half the endosperm removed. Deep seeding reduced cold hardiness. The treatments had a marked effect on the dry weight of crowns and a smaller effect on crown total available carbohydrate content, both of which were positively correlated with cold hardiness, whereas water content was negatively correlated with cold hardiness.

scholarly journals Stimulation of lignin synthesis via the PAL-associated metabolic pathway in wheat plants (Tríticum aestívum L.)

2021 ◽  
Vol 291 ◽  
pp. 02017
Author(s):  
Pavel Feduraev ◽  
Artem Pungin ◽  
Anastasiia Riabova ◽  
Elina Tokupova ◽  
Liubov Skrypnik
Keyword(s):  
Triticum Aestivum ◽  
Metabolic Pathway ◽  
Cell Walls ◽  
Phenylalanine Ammonia Lyase ◽  
Lignin Content ◽  
Triticum Aestivum L ◽  
Soft Wheat ◽  
Nutrient Media ◽  
Key Enzyme ◽  
Stimulation Of

The paper demonstrates an approach to increasing the accumulation of lignin in plants of soft wheat (Tríticum aestívum L.) at the early stages of ontogenesis, by means of substrate stimulation of the key enzyme of the synthesis of phenylpropanoids – phenylalanine-ammonia-lyase. It was shown that plants grown on nutrient media containing phenialanine or tyrosine at a concentration of 500 μM significantly increased the lignin content of cell walls compared to controls.

Chromosomes in 'Cadet' and 'Rescue' wheats carrying loci for cold hardiness and vernalization response

1986 ◽  
Vol 28 (6) ◽  
pp. 991-997 ◽  
Author(s):  
D. W. A. Roberts
Keyword(s):  
Triticum Aestivum ◽  
Spring Wheat ◽  
Cold Hardiness ◽  
Rank Order ◽  
Triticum Aestivum L ◽  
Wheat Cultivars ◽  
Chromosome Substitution ◽  
Vernalization Response ◽  
Substitution Lines ◽  
Chromosome Substitution Lines

'Rescue', 'Cadet', and the 42 reciprocal chromosome substitution lines derived from these two spring wheat cultivars were tested for vernalization response and cold hardiness. Cold hardiness was tested after hardening under a 16-h day for 8 weeks with 6 °C day and 4 °C night temperatures or in the dark for 7 weeks at 0.8 °C followed by 8 weeks at −5 °C. Chromosomes 5A, 5B, 7B, and possibly 2A carried loci for vernalization response. Chromosomes 2A, 5A, and 5B carried loci affecting cold hardiness measured after 8 weeks in the light at 6 °C during the day and 4 °C at night, whereas chromosomes 6A, 3B, 5B, and 5D were involved in cold hardiness after hardening in the dark at 0.8 °C followed by −5 °C. The results suggest that the rank order of cultivars for cold hardiness depends on the hardening technique used since the two different techniques tested had different genetic and presumably somewhat different biochemical bases.Key words: Triticum aestivum L., cold hardiness, vernalization.

AN EVALUATION OF SEVERAL CHEMICAL TESTS AS POSSIBLE SELECTION MEASURES FOR WINTERHARDINESS IN WHEAT

1983 ◽  
Vol 63 (1) ◽  
pp. 115-119 ◽  
Author(s):  
L. V. GUSTA ◽  
D. B. FOWLER ◽  
N. J. TYLER
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Key Words ◽  
Uronic Acid ◽  
Cold Hardiness ◽  
Triticum Aestivum L ◽  
Survival Prediction ◽  
Selection Measures ◽  
Highly Correlated ◽  
Chemical Characters

Ten chemical characters and crown LT50s were measured on 14 cold-hardened cultivars of winter wheat (Triticum aestivum L. em. Thell.) to determine their usefulness in winter survival prediction tests. Differences among genotypes with a range of cold hardiness potential (LT50 −13 °C to −20 °C) were significant for 6 to 10 characters evaluated. Crown LT50 was the best prediction of field survival (FSI). Cell sap viscosity, total crown nitrogen, crown ethanol, insoluble nitrogen, and crown uronic acid were highly correlated with both FSI and LT50. Proline, pH and ATP were not significantly correlated with either FSI or LT50.Key words: Chemical tests, selection, winterhardiness, wheat

USE OF LETHAL DOSE TEMPERATURE ESTIMATES AS INDICES OF FROST TOLERANCE FOR WHEAT COLD ACCLIMATED UNDER NATURAL AND CONTROLLED ENVIRONMENTS

1973 ◽  
Vol 53 (3) ◽  
pp. 489-494 ◽  
Author(s):  
M. K. POMEROY ◽  
D. B. FOWLER
Keyword(s):  
Triticum Aestivum ◽  
Cold Acclimation ◽  
Spring Wheat ◽  
Cold Hardiness ◽  
Lethal Dose ◽  
Maximum Level ◽  
Triticum Aestivum L ◽  
Frost Tolerance ◽  
Controlled Environments

LD50 (lethal dose 50) temperature estimates were utilized to study cold acclimation in three winter and one spring wheat (Triticum aestivum L.) cultivars grown under natural and controlled environments. Highly significant differences were found among cultivars for both rate and maximum level of cold acclimation with the acclimation patterns being similar for both environments. The advantages and limitations to the use of lethal dose temperature ratings in cold hardiness studies are discussed.

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