A critical update on seed dormancy. I. Primary dormancy

1995 ◽  
Vol 5 (2) ◽  
pp. 61-73 ◽  
Author(s):  
Henk W. M. Hilhorst
Keyword(s):  
Cell Wall ◽  
Abscisic Acid ◽  
Seed Dormancy ◽  
Decisive Role ◽  
Morphological Development ◽  
Primary Dormancy ◽  
Whole Seed ◽  
Aba Content ◽  
Cell Wall Properties

AbstractThe emphasis of modern dormancy research is almost entirely on the form of dormancy that is acquired during seed development, primary dormancy. Abscisic acid (ABA) appears to be intimately involved in its regulation. The action of abscisic acid has also been implied in many other developmental processes. The coincidence of developmental events, such as dehydration and completion of maturation, with the acquisition of primary dormancy suggests that dormancy is influenced by these processes. Germinability, both during development and after maturation, is sometimes directly correlated with ABA content. The lack of such a correlation may be explained by assuming a decisive role for the responsiveness to ABA or other overriding factors. ABA has been detected in all seed components. The different seed tissues may all contribute, to various extents, to the degree of whole seed dormancy. It is concluded that ABA action in dormancy regulation is not restricted to the embryo but is also located in endospermic tissue. In addition, a role of ABA in the morphological development of germination modifying seed tissues is proposed. The mechanism for ABA action appears to be associated with cell wall properties.

Abscisic acid and the control of seed dormancy and germination

2010 ◽  
Vol 20 (2) ◽  
pp. 55-67 ◽  
Author(s):  
Eiji Nambara ◽  
Masanori Okamoto ◽  
Kiyoshi Tatematsu ◽  
Ryoichi Yano ◽  
Mitsunori Seo ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
High Temperature ◽  
Seed Dormancy ◽  
Plant Hormone ◽  
The Core ◽  
Aba Metabolism ◽  
External Cues ◽  
Aba Content ◽  
Seed Dormancy And Germination

AbstractAbscisic acid (ABA) is a plant hormone that regulates seed dormancy and germination. Seeds undergo changes in both ABA content and sensitivity during seed development and germination in response to internal and external cues. Recent advances in functional genomics have revealed the integral components involved in ABA metabolism (biosynthesis and catabolism) and perception, the core signalling pathway, as well as the factors that trigger ABA-mediated transcription. These allow for comparative studies to be conducted on seeds under different environmental conditions and from different genetic backgrounds. This review summarizes our understanding of the control of ABA content and the responsiveness of seeds to afterripening, light, high temperature and nitrate, with a focus on which tissues are involved in its metabolism and signalling. Also described are the regulators of ABA metabolism and signalling, which potentially act as the node for hormone crosstalk. Integration of such knowledge into the complex and diverse events occurring during seed germination will be the next challenge, which will allow for a clearer understanding of the role of ABA.

Regulation of seed dormancy by abscisic acid and DELAY OF GERMINATION 1

2015 ◽  
Vol 25 (2) ◽  
pp. 82-98 ◽  
Author(s):  
Bas J.W. Dekkers ◽  
Leónie Bentsink
Keyword(s):  
Abscisic Acid ◽  
Seed Dormancy ◽  
Plant Hormone ◽  
Complex Trait ◽  
Hormone Interactions ◽  
Physiological Dormancy ◽  
Recent Developments ◽  
Radicle Emergence ◽  
Dormancy Induction

AbstractPhysiological dormancy has been described as a physiological inhibiting mechanism that prevents radicle emergence. It can be caused by the embryo (embryo dormancy) as well as by the structures that cover the embryo. One of its functions is to time plant growth and reproduction to the most optimal season and therefore, in nature, dormancy is an important adaptive trait that is under selective pressure. Dormancy is a complex trait that is affected by many loci, as well as by an intricate web of plant hormone interactions. Moreover, it is strongly affected by a multitude of environmental factors. Its induction, maintenance, cycling and loss come down to the central paradigm, which is the balance between two key hormonal regulators, i.e. the plant hormone abscisic acid (ABA), which is required for dormancy induction, and gibberellins (GA), which are required for germination. In this review we will summarize recent developments in dormancy research (mainly) in the model plant Arabidopsis thaliana, focusing on two key players for dormancy induction, i.e. the plant hormone ABA and the DELAY OF GERMINATION 1 (DOG1) gene. We will address the role of ABA and DOG1 in relation to various aspects of seed dormancy, i.e. induction during seed maturation, loss during dry seed afterripening, the rehydrated state (including dormancy cycling) and the switch to germination.

scholarly journals The Role of Abscisic Acid in Heat Stress-induced Secondary Dormancy in Apple Seeds

HortScience ◽  
1991 ◽  
Vol 26 (2) ◽  
pp. 175-177 ◽  
Author(s):  
Jocelyn A. Ozga ◽  
F.G. Dennis
Keyword(s):  
Abscisic Acid ◽  
Heat Stress ◽  
Germination Capacity ◽  
Embryonic Axes ◽  
Secondary Dormancy ◽  
Golden Delicious ◽  
Aba Content ◽  
Seed Coats ◽  
Apple Seeds

Exposure of stratified apple (Malus domestics Borkh. cv. Golden Delicious) seeds to 30C induces secondary dormancy. To determine if an increase in abscisic acid (ABA) content was associated with the loss in germination capacity, stratified seeds (3,- 6, or 9 weeks at 5C) were held at 30C for 0, 3, or 6 days. Stratification at 5C either had no effect or increased ABA content in embryonic axes, cotyledons, and seed coats. Exposure to 30C after stratification either did not affect or decreased ABA content of embryonic axes and seed coats; in contrast, cotyledonary ABA was increased. Seed coats, cotyledons, and embryonic axes stratified for 3, 6, or 9 weeks at 20C contained the same or higher levels of ABA in comparison with nonstratified seeds or seeds stratified at SC. Changes in ABA levels were not consistently correlated with changes in germination capacity during stratification or after exposure to 30C. These data suggest that changes in ABA are not related to changes in dormancy. Chemical names used: abscisic acid (ABA); butylated hydroxy-toluene (BHT); n-(trichloromethyl) thio-4-cyclohexene-1,2-dicarboximide(Captan).

The great diversity in kinds of seed dormancy: a revision of the Nikolaeva–Baskin classification system for primary seed dormancy

2021 ◽  
pp. 1-29
Author(s):  
Jerry M. Baskin ◽  
Carol C. Baskin
Keyword(s):  
Seed Dormancy ◽  
Seed Coat ◽  
Classification System ◽  
Primary Dormancy ◽  
Morphophysiological Dormancy ◽  
Physiological Dormancy ◽  
Whole Seed ◽  
Dust Seeds ◽  
Impermeable Seed Coat ◽  
Morphological Dormancy

Abstract This review provides a revised and expanded word-formula system of whole-seed primary dormancy classification that integrates the scheme of Nikolaeva with that of Baskin and Baskin. Notable changes include the following. (1) The number of named tiers (layers) in the classification hierarchy is increased from three to seven. (2) Formulae are provided for the known kinds of dormancy. (3) Seven subclasses of class morphological dormancy are designated: ‘dust seeds’ of mycoheterotrophs, holoparasites and autotrophs; diaspores of palms; and seeds with cryptogeal germination are new to the system. (4) Level non-deep physiological dormancy (PD) has been divided into two sublevels, each containing three types, and Type 6 is new to the system. (5) Subclass epicotyl PD with two levels, each with three types, has been added to class PD. (6) Level deep (regular) PD is divided into two types. (7) The simple and complex levels of class morphophysiological dormancy (MPD) have been expanded to 12 subclasses, 24 levels and 16 types. (8) Level non-deep simple epicotyl MPD with four types is added to the system. (9) Level deep simple regular epicotyl MPD is divided into four types. (10) Level deep simple double MPD is divided into two types. (11) Seeds with a water-impermeable seed coat in which the embryo-haustorium grows after germination (Canna) has been added to the class combinational dormancy. The hierarchical division of primary seed dormancy into many distinct categories highlights its great diversity and complexity at the whole-seed level, which can be expressed most accurately by dormancy formulae.

Dormancy in sunflower line A-3: the role of the pericarp

Botany ◽  
2017 ◽  
Vol 95 (8) ◽  
pp. 853-858
Author(s):  
Ana E. Vigliocco ◽  
Andrea M. Andrade ◽  
Lilia I. Lindström ◽  
Sergio G. Alemano
Keyword(s):  
Seed Dormancy ◽  
Cross Sections ◽  
Morphological Characteristics ◽  
Germination Percentage ◽  
Physical Dormancy ◽  
Relative Contribution ◽  
Sunflower Line ◽  
Whole Seed ◽  
Final Degree

Sunflower (Helianthus annuus L.) can often display seed dormancy, which causes a delay for immediate sowing. The final degree of “whole seed” dormancy is determined by the contributions of the tissues that comprise it, such as, embryo, seed coat, and (or) pericarp. The sunflower dormancy can be reduced during after-ripening and by removing seed constraints. Our objective was to study how the conditions of storage and removal of the pericarp affect the level of dormancy in line A-3. Also we provide insight on the basis of the morphological characteristics of A-3 pericarp-imposed dormancy. A germination test was conducted on dry cypselas with and without pericarp, at 30 and 70 days after harvest. For histological analysis, permanent slides of pericarp cross-sections were obtained. The germination percentage showed significant differences between cypselas with intact pericarp (30 days after harvest = 26%; 70 days after harvest = 77%), and cypselas without pericarp (30 days after harvest = 65%; 70 days after harvest = 96%). This indicates that the pericarp plays an important role in regulating physical dormancy in the seed of sunflower line A-3, and that its relative contribution to the dormancy level is modified during after-ripening.

scholarly journals   Role of abscisic acid and drought stress on the activities of antioxidant enzymes in wheat

2012 ◽  
Vol 58 (No. 4) ◽  
pp. 181-185 ◽  
Author(s):  
A. Bano ◽  
F. Ullah ◽  
A. Nosheen
Keyword(s):  
Abscisic Acid ◽  
Drought Stress ◽  
Seed Treatment ◽  
Oxygen Species ◽  
Wheat Cultivars ◽  
Drought Tolerant ◽  
Relative Water ◽  
Aba Content ◽  
Endogenous Aba

The effect of drought stress and abscisic acid (ABA) applied at tillering stage (55 days after sowing) was compared in 2 wheat cultivars differing in drought tolerance. The activities of superoxide dismutase (SOD) and peroxidase (POD) and contents of endogenous ABA in plants were measured at 3 days of drought stress in cv. Chakwal-97 (drought tolerant) and cv. Punjab-96 (drought susceptible). ABA was applied at 10<sup>&ndash;6</sup> mol/L as presowing seed treatment for 18 h. Drought tolerant cultivar has a more efficient mechanism to scavenge reactive oxygen species as shown by a significant increase in the activity of antioxidant enzyme SOD. Under drought stress, ABA significantly increased the activities of SOD and POD, showing a significant decline on rewatering. The relative water content was significantly increased by ABA priming under drought stress in both wheat cultivars. The sensitive cultivar exhibiting lower endogenous ABA content was more responsive to ABA priming. On rewatering, the magnitude of recovery from drought stress was greater in tolerant cultivar. ABA was highly effective in improving grain weight of tolerant cultivar under drought stress. &nbsp;

scholarly journals On the role of abscisic acid in seed dormancy of red rice

2007 ◽  
Vol 58 (12) ◽  
pp. 3449-3462 ◽  
Author(s):  
A. Gianinetti ◽  
P. Vernieri
Keyword(s):  
Abscisic Acid ◽  
Seed Dormancy ◽  
Red Rice

Dormancy-break and germination in seeds of Prunus campanulata (Rosaceae): role of covering layers and changes in concentration of abscisic acid and gibberellins

2007 ◽  
Vol 17 (1) ◽  
pp. 21-32 ◽  
Author(s):  
Shun-Ying Chen ◽  
Ching-Te Chien ◽  
Jeng-Der Chung ◽  
Yuh-Shyong Yang ◽  
Shing-Rong Kuo
Keyword(s):  
Abscisic Acid ◽  
Seed Coat ◽  
Carotenoid Biosynthesis ◽  
Inhibitory Effect ◽  
Germination Percentage ◽  
Biosynthesis Inhibitor ◽  
Breaking Dormancy ◽  
Aba Content ◽  
Ga Biosynthesis

AbstractIntact seeds (seed+endocarp) from freshly harvested fruits of Prunus campanulata were dormant, and required 4–6 weeks of warm followed by 8 weeks of cold stratification for maximum germination percentage. Removing both endocarp and seed coat, however, promoted germination in a high percentage of non-stratified seeds. Treatment of intact, non-stratified seeds with gibberellic acid (GA3) was only partially effective in breaking dormancy. However, GA3 promoted germination of non-stratified seeds in which the endocarp (but not the seed coat) had been removed. The order of abscisic acid (ABA) concentration in fresh seeds was endocarp > seed coat > embryo, and its concentration in endocarp plus seed coat was about 6.2-fold higher than that in the embryo. Total ABA contents of seeds subjected to warm and/or cold moist stratification were reduced 6- to 12-fold. A higher concentration of GA4 was detected in embryos of non-dormant than in those of dormant seeds. Fluridone, a carotenoid biosynthesis inhibitor, was efficient in breaking dormancy of Prunus seeds. Paclobutrazol, a GA biosynthesis inhibitor, completely inhibited seed germination, and the inhibitory effect could be partially reversed by GA4, but not by GA3. Thus, dormancy in P. campanulata seeds is imposed by the covering layers. Dormancy break is accompanied by a decrease in ABA content of the covering layers and germination by an increase of embryonic GA4 content.

scholarly journals Abscisic acid induced seed dormancy and climate resilience in fox tail millet (Setaria italica L.) genotypes

2016 ◽  
Vol 8 (2) ◽  
pp. 570-573
Author(s):  
Anil Sebastian ◽  
S.N. Vasudevan ◽  
B. Kissan ◽  
I. Sangeeta Macha ◽  
S.R. Doddagoudar
Keyword(s):  
Climate Change ◽  
Abscisic Acid ◽  
Laboratory Experiment ◽  
Seed Dormancy ◽  
Foxtail Millet ◽  
Setaria Italica ◽  
Climate Resilience ◽  
Test Kit ◽  
Food And Nutrition ◽  
Aba Content

A laboratory experiment was conducted at Department of Seed Science and Technology, UAS Raichur to estimate ABA content in foxtail millet (Setaria italica L.) using Phytodetek ABA Test Kit. ABA estimation in millets is helpful to trace out the reason behind the dormancy in millets and is less explored. Nine genotypes were studied in the present investigation. Among the foxtail millet genotypes, the highest dormancy duration of 35 days was observed in two genotypes viz., DHFt-4-5 and DHFt-5-3 and slight dormancy was noticed in the genotype DHFt- 35-1. The genotype DHFt-35-1 recorded lowest ABA concentration of 3.199 pmol/g f. w. followed by genotypes DHFt-2-5 and DHFt-2-5-1 (3.266 and 3.291 pmol/g f. w. respectively). Highest ABA concentration was found in DHFt-5-3 (3.404 pmol/g f. w.) followed by DHFt-4-5 (3.396 pmol/g f. w.). Thus it was concluded that ABA in millet seeds makes them ‘climate smart crops’ and during the climate change regime, it is only millets that can ensure India’s food and nutrition needs in future.

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