Release of dormancy in sunflower embryos by dry storage: involvement of gibberellins and abscisic acid

1994 ◽  
Vol 4 (2) ◽  
pp. 57-62 ◽  
Author(s):  
J. Bianco ◽  
G. Garello ◽  
M. T. Le Page-Degivry
Keyword(s):  
Abscisic Acid ◽  
Helianthus Annuus ◽  
Slight Improvement ◽  
The Third ◽  
Dry Storage ◽  
Drying Treatment ◽  
Aba Content ◽  
Embryo Metabolism ◽  
Aba Synthesis ◽  
Fresh Embryos

AbstractExcised Helianthus annuus L. embryos became dormant during the third week after anthesis. At this stage a short drying treatment (3 d) led to a slight improvement in germination but a 6-week dry storage caused a complete release from dormancy. The short drying treatment, however, elicited the embryos' response to an exogenous concentration of GAs which was unable to promote germination of fresh embryos. It therefore appeared that a short drying treatment changed the sensitivity to GAs but was not capable of directing embryo metabolism completely towards a germinative mode. Moreover, this drying treatment reduced considerably the ABA content in both the axis and the embryo. Nevertheless, no correlation could be established between germinability and the ABA content since the amount of ABA was not modified by the 6-week dry storage. The key step for predisposing the seeds to germinate is the suppression of the capacity for ABA synthesis in the axis, a suppression which takes place during 6-week dry storage.

Association Between Loss of Leaf Turgor, Abscisic Acid Levels and Seed Set in Two Wheat Cultivars

1984 ◽  
Vol 11 (3) ◽  
pp. 143 ◽  
Author(s):  
JM Morgan ◽  
RW King
Keyword(s):  
Abscisic Acid ◽  
Seed Set ◽  
Developmental Stages ◽  
Wheat Plant ◽  
Wheat Cultivars ◽  
Pressure Sensing ◽  
Sensing Mechanism ◽  
Effects Of Stress ◽  
Aba Content ◽  
Aba Synthesis

An increase in abscisic acid (ABA) content of the spike and a decrease in seed set of the spike resulted from the withholding of water from the wheat plant during pollen meiosis. The leaf was probably the source of this ABA since spike turgor was maintained whereas leaf turgor was lost. A change in elasticity of the leaf was associated with its loss of turgor (0-0.4 MPa leaf turgor). The correlation with ABA content points to this change in elasticity as a possible pressure-sensing mechanism regulating ABA synthesis at low or zero turgor. For the two cultivars examined, differences in seed set under well-watered conditions were associated with differences in ABA content of the spike. However, complete infertility was not observed and, also, all florets were affected to the same extent. Possibly pollen is sensitive to stress over a range of developmental stages and not solely during meiosis. Alternatively, the effects of stress may linger for some time after rewatering of the plants.

scholarly journals Fluctuating temperatures terminate dormancy inCynara cardunculusseeds by turning off ABA synthesis and reducing ABA signalling, but not stimulating GA synthesis or signalling

2014 ◽  
Vol 24 (2) ◽  
pp. 79-89 ◽  
Author(s):  
H. Roberto Huarte ◽  
Virginia Luna ◽  
Eduardo A. Pagano ◽  
Jorge A. Zavala ◽  
Roberto L. Benech-Arnold
Keyword(s):  
Abscisic Acid ◽  
Physiological Responses ◽  
Cynara Cardunculus ◽  
Physiological Dormancy ◽  
Aba Content ◽  
Fluctuating Temperatures ◽  
Ga Content ◽  
Aba Synthesis ◽  
Regulatory Sites ◽  
Stimulation Of

AbstractFluctuating temperatures terminate seed dormancy in many species, includingCynara cardunculus(L.) var.sylvestris. Termination of physiological dormancy requires low ratios of abscisic acid (ABA)/gibberellins (GA). In a previous paper we have shown that physiological responses to fluctuating temperatures comprise a reduction of abscisic acid (ABA) content and sensitivity. However, a possible stimulation of GA synthesis was also suggested as part of the mechanism. That possible stimulation, as well as the identification of potential regulatory sites for ABA and GA metabolism and signalling involved in the termination of dormancy by fluctuating temperatures, are yet to be determined. In this study, we measured GA content and sensitivity in seeds incubated under constant and fluctuating temperatures. We also assessed the expression of several genes involved in ABA and GA metabolism and signalling. Our results show that fluctuating temperatures reduce ABA/GA ratios through a reduction in ABA accumulation during incubation but without altering GA synthesis as compared to that observed under constant temperatures. On the other hand, fluctuating temperatures did not increase sensitivity to GA. Fluctuating temperatures reduced the expression ofCycaNCEDandCycaABI5(ABA synthesis and signalling genes) with a temporal pattern that coincides with the interruption of ABA accumulation that precedes germination of seeds incubated under fluctuating temperatures. However, fluctuating temperatures did not modify the expression ofCycaCYP707A2(ABA inactivation) as compared to that observed under constant temperatures. Consistent with our determinations of GA content and sensitivity, fluctuating temperatures did not modify the expression of GA synthesis (CycaGA3ox) and signalling genes (CycaRGL2andCycaGAI) in relation to that observed at constant temperatures. These results show that fluctuating temperatures terminate dormancy inCynara cardunculusseeds through an interruption in ABA accumulation and a reduction in ABA signalling exerted at the level ofCycaNCEDandCycaABI5expression.

scholarly journals Dr P. Davis, prof. Mann et al. — Fatal Nausea and Vomiting of Pregnancy. - (New-Jork Medic. Journ., 1894, 28 / VII, p. 121). Fatal nausea and vomiting in pregnant women. Dr. Terrel. - The Black vomit of Pregnancy. - (Ibid, 18 / VIII p. 212). Black vomiting in pregnant women

2020 ◽  
Vol 9 (7-8) ◽  
pp. 698-699
Author(s):  
M. Ginzburg
Keyword(s):  
Pregnant Woman ◽  
Pregnant Women ◽  
Uterine Cervix ◽  
Severe Pain ◽  
Fatty Degeneration ◽  
Nausea And Vomiting ◽  
Minor Bleeding ◽  
Slight Improvement ◽  
Severe Nausea ◽  
The Third

Dr. Davis reported three fatal cases of vomiting during pregnancy. In the first of them, the pregnant woman suffered from gastric disorders before pregnancy; her vomiting was incessant and very exhausted her. She died at 2 months of pregnancy. Before dying, she developed a petechia-shaped spotty rash. In the second case, severe nausea and vomiting occurred at 3 weeks of pregnancy with severe pain and belching, locally: prolapsus and anteflexio uteri. The usual treatment. At 14 weeks, the anteflexed uterus was infringed at the bottom behind the pubis; the correction did not reduce vomiting. The expansion of the neck was accompanied by a slight improvement. It was decided to empty the uterus, which was done without difficulty and with minor bleeding. The patient, however, died soon after. An autopsy showed that the tissue of the uterine cervix was abnormally hard (fibrous); the uterus, ovaries, and tubes were normal; the blood was thin, fatty degeneration of the heart. In the third case, the patient, in addition to nausea and vomiting, suffered from severe pain in the epigastric region and vomiting had a coffee color. Everything possible was done, but nothing helped: the patient died.

Differential accumulation of abscisic acid and its catabolites in drought-sensitive and drought-tolerant sunflower seeds

2009 ◽  
Vol 19 (4) ◽  
pp. 201-211 ◽  
Author(s):  
Andrea Andrade ◽  
Ana Vigliocco ◽  
Sergio Alemano ◽  
Daniel Alvarez ◽  
Guillermina Abdala
Keyword(s):  
Abscisic Acid ◽  
No Reduction ◽  
Water Environment ◽  
Embryonic Axis ◽  
Sunflower Seeds ◽  
Maternal Plant ◽  
Drought Tolerant ◽  
Field Lines ◽  
Aba Content ◽  
Germinated Seeds

AbstractEleven sunflower (Helianthus annuus L.) inbred lines were evaluated in field and laboratory studies under drought and irrigation. In the field, lines B59, R419 and B67 had reduced seed and oil yield under drought, while no reduction was observed for R432, HAR4 and B71. Lines HA89, R415, R049, RHA274 and R423 presented intermediate responses. In laboratory tests, seeds of line B59 had reduced germination percentages at 200 and 400 mM mannitol, while germination of seeds of lines R432, B71, HAR4, RHA274 and HA89 was reduced only at 400 mM mannitol. Drought-sensitive B59 and drought-tolerant B71 grown under irrigation and drought conditions in the field were selected for hormone assays. Abscisic acid (ABA) and its catabolites in pericarp, embryonic axis and cotyledons of dry and germinated seeds of B59 and B71 were determined. ABA was the major component of the pericarp of dry seeds from B71 and B59 plants grown under drought. The embryonic axis of B71 dry seeds from drought-grown plants also showed high ABA content. The major findings from this study are: (1) the drought-sensitive and -tolerant lines exhibited different ABA and catabolite profiles; (2) water environment during maternal plant growth affected ABA content and the composition of catabolites in mature and germinated seeds; (3) ABA content did not affect germination performance in our conditions; and (4) the dry and germinated seed parts showed different ABA and catabolite profiles.

Profitability Assessment of Abscisic Acid Application on Sunflower (Helianthus annuus L.) Hybrid under Drought and Well Watered Conditions

2013 ◽  
Vol 12 (5) ◽  
pp. 448-454
Author(s):  
Safdar Hussain ◽  
M. Farrukh Saleem ◽  
Javaid Iqbal ◽  
Sajid Mahmood Nadeem ◽  
Muhammad Ahmad ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Helianthus Annuus ◽  
Helianthus Annuus L ◽  
Profitability Assessment

Changes in abscisic acid content during and after drought are related to carbohydrate mobilization and hydraulic recovery in poplar stems

2020 ◽  
Vol 40 (8) ◽  
pp. 1043-1057 ◽  
Author(s):  
Cecilia Brunetti ◽  
Tadeja Savi ◽  
Andrea Nardini ◽  
Francesco Loreto ◽  
Antonella Gori ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Hydraulic Conductivity ◽  
Stomatal Closure ◽  
Populus Nigra ◽  
Plant Responses ◽  
Stem Water Potential ◽  
Transport Efficiency ◽  
Drought Relief ◽  
Aba Content ◽  
Abscisic Acid Content

Abstract Drought compromises plant's ability to replace transpired water vapor with water absorbed from the soil, leading to extensive xylem dysfunction and causing plant desiccation and death. Short-term plant responses to drought rely on stomatal closure, and on the plant's ability to recover hydraulic functioning after drought relief. We hypothesize a key role for abscisic acid (ABA) not only in the control of stomatal aperture, but also in hydraulic recovery. Young plants of Populus nigra L. were used to investigate possible relationships among ABA, non-structural carbohydrates (NSC) and xylem hydraulic function under drought and after re-watering. In Populus nigra L. plants subjected to drought, water transport efficiency and hydraulic recovery after re-watering were monitored by measuring the percentage loss of hydraulic conductivity (PLC) and stem specific hydraulic conductivity (Kstem). In the same plants ABA and NSC were quantified in wood and bark. Drought severely reduced stomatal conductance (gL) and markedly increased the PLC. Leaf and stem water potential, and stem hydraulic efficiency fully recovered within 24 h after re-watering, but gL values remained low. After re-watering, we found significant correlations between changes in ABA content and hexoses concentration both in wood and bark. Our findings suggest a role for ABA in the regulation of stem carbohydrate metabolism and starch mobilization upon drought relief, possibly promoting the restoration of xylem transport capacity.

scholarly journals Pericarp-mediated chemical dormancy controls the fruit germination of the invasive hoary cress (Lepidium draba), but not of hairy whitetop (Lepidium appelianum)

Weed Science ◽  
2019 ◽  
Vol 67 (05) ◽  
pp. 560-571 ◽  
Author(s):  
Said Mohammed ◽  
Veronika Turečková ◽  
Danuše Tarkowská ◽  
Miroslav Strnad ◽  
Klaus Mummenhoff ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Weed Management ◽  
Wash Water ◽  
Invasive Weeds ◽  
Surface Sterilization ◽  
Dry Storage ◽  
Physiological Dormancy ◽  
Hoary Cress ◽  
Lepidium Draba ◽  
Mechanical Constraint

AbstractThis study provides a comparative analysis of the dormancy and germination mechanisms of the indehiscent fruits of hoary cress (Lepidium draba L.) and hairy whitetop (Lepidium appelianum Al-Shehbaz), two invasive weeds of the Brassicaceae. Germination assays comparing isolated seeds (manually removed from the fruits) and intact indehiscent fruits showed that the isolated seeds are nondormant and provided full germination for both species. In contrast to this, the species differed in the germination properties of their indehiscent fruits, in that L. appelianum fruits were nondormant, while the L. draba fruit coat (pericarp) conferred a coat-imposed dormancy. The pericarp of L. draba fresh fruit was water permeable, and neither mechanical scarification nor surface sterilization affected germination, supporting the concept that pericarp-mediated dormancy was not due to water impermeability or mechanical constraint. Washing of L. draba fruits with water, afterripening (dry storage), and treatment with gibberellin (GA) stimulated the germination of this species, all of which are indicative of physiological dormancy. Analyses of endogenous abscisic acid (ABA) and GA levels combined with treatment experiments with wash water from fresh and afterripened L. draba pericarps and with ABA dose–response quantification of germination revealed that ABA is a key component of a pericarp-mediated chemical dormancy in this species. Consistent with this, pericarp ABA levels decreased during afterripening and upon fruit washing, and isolated fresh or afterripened seeds did not differ in their ABA sensitivities. The possible roles of the ABA-mediated pericarp dormancy for the germination ecophysiology and weed management of these species are discussed.

scholarly journals Involvement of Endogenous Abscisic Acid in Onset and Release of Helianthus annuus Embryo Dormancy

1990 ◽  
Vol 92 (4) ◽  
pp. 1164-1168 ◽  
Author(s):  
Marie-Thérèse Le Page-Degivry ◽  
Philippe Barthe ◽  
Ginette Garello
Keyword(s):  
Abscisic Acid ◽  
Helianthus Annuus ◽  
Endogenous Abscisic Acid ◽  
Embryo Dormancy

Inhibition of Flowering in Lolium temulentum L. By Water Stress: a Role for Abscisic Acid

1977 ◽  
Vol 4 (2) ◽  
pp. 225 ◽  
Author(s):  
RW King ◽  
LT Evans
Keyword(s):  
Abscisic Acid ◽  
Water Stress ◽  
Long Day ◽  
Relative Water ◽  
The One ◽  
Floral Evocation ◽  
Leaf Photosynthetic Rate ◽  
Response To Water ◽  
Aba Content ◽  
High Intensity Light

A brief, 8-h water stress during the induction of flowering in L. temulentum reduces the flowering response, the more so the greater the stress. Water stress also affected leaf photosynthetic rate, relative water content of leaves and leaf elongation. Water stress was most inhibitory to flowering when applied during the period of high-intensity light at the beginning of the one long day. The abscisic acid (ABA) content of leaves increased up to 30-fold during the imposition of water stress and fell rapidly after stress was relieved, regardless of when the stress was imposed. The greater the stress, the higher was the level of ABA in leaves and the greater was the inhibition of flowering. The ABA content of apices also rose in response to water stress, in some cases during the stress treatment but usually 8-22 h later. Flowering was inhibited when apical ABA contents were high at the end of the long day. Although water stress may influence the flowering of plants in several ways, these experiments suggest that water stress during the long day induction of L. temulentum inhibits flowering by raising the content of ABA at the shoot apex during floral evocation.

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