scholarly journals Differences in seed dormancy associated with the domestication ofCucurbita maxima: elucidation of some mechanisms behind this response

2017 ◽  
Vol 28 (1) ◽  
pp. 1-7
Author(s):  
Analía B. Martínez ◽  
Verónica Lema ◽  
Aylen Capparelli ◽  
Fernando López Anido ◽  
Roberto Benech-Arnold ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Seed Dormancy ◽  
Seed Coat ◽  
Mother Plant ◽  
Temperature Dependent ◽  
Wild Genotype ◽  
Embryo Germination ◽  
In The Wild ◽  
Incubation Temperatures ◽  
Aba Content

AbstractThis work presents the results of physiological studies developed to understand modifications linked to the reduction of seed dormancy provoked by domestication processes. The experiments performed compared wild and domesticatedCucurbitasubspecies and their hybrids developed by reciprocal crossings. Seeds of two accessions of the wild subspecies presented dormancy, but it was largely reduced in seeds from the domesticated genotype, and partially reverted in hybrids, especially in those obtained when the domesticated genotype was used as the mother plant. In addition, naked embryos of all subspecies did not display dormancy when incubation was performed at 28°C, but embryo germination was progressively reduced only in the wild genotype under decreasing incubation temperatures (22 and 16°C). In the embryos, abscisic acid (ABA) concentrations were similar in both domesticated and wild subspecies, whereas in the seed coat, it was threefold higher in the wild subspecies. The naked embryos from the wild subspecies were far more responsive to ABA than those from the domesticated subspecies. These results indicate that dormancy in the wild subspecies is imposed by the seed coat tissues and that this effect is mediated by their high ABA content and the sensitivity of the embryos to ABA. These physiological aspects were apparently removed by domestication along with the temperature-dependent response for germination.

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.

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.

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.

CHANGES IN ABSCISIC ACID AND GIBBERELLIN LEVELS IN APPLE SEEDS DURING STRATIFICATION AND THEIR RELATIONSHIP TO GENETIC COMPACTION

1978 ◽  
Vol 58 (3) ◽  
pp. 761-767 ◽  
Author(s):  
J. M. LEE ◽  
N. E. LOONEY
Keyword(s):  
Abscisic Acid ◽  
Seed Coat ◽  
Acid Content ◽  
Controlled Crosses ◽  
Aba Content ◽  
Abscisic Acid Content ◽  
Apple Seeds

The levels of abscisic acid (ABA) and gibberellin-like (GA-like) substances were examined in apple seeds from controlled crosses known to produce 0 or 50% compact seedlings. All seed lots exhibited similar changes in ABA and GA-like substances during an 80-day stratification period. The seeds were divided into two fractions, seed coat plus integuments (SC + I) and the embryo plus cotyledons (E + C). The ABA content of the E + C fraction was low relative to that in the SC +I fraction and gradually decreased during stratification. Abscisic acid content of the SC + I fraction increased markedly early in the stratification period and then gradually decreased. The GA-like activity, found primarily in the SC + I fraction, gradually increased (up to 40 days) and then decreased.

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.

scholarly journals Physical seed dormancy in Abrus precatorious (Ratti): a scientific validation of indigenous technique

2021 ◽  
Vol 2 ◽  
Author(s):  
Rajender Kumar Sharma
Keyword(s):  
Indigenous People ◽  
Seed Dormancy ◽  
Seed Coat ◽  
Seed Weight ◽  
Mass Measurement ◽  
Storage Period ◽  
Abrus Precatorius ◽  
Moisture Storage ◽  
Moisture Conditions ◽  
Scientific Validation

Abstract Seeds of Abrus precatorius L. (Fabaceae) were used as weight measure by Indigenous people. Where, the seeds were referred as Ratti; a traditional Indian unit of mass measurement. Seed weight fluctuates depending upon age, moisture, storage-period/conditions. Therefore, use of seeds as a weighing unit become dubious and need to be validated. For this purpose, seeds of A. precatorious were subjected to different moisture conditions and periodically monitored. Surprisingly, there was no change in seed weight was observed, indicating the impermeability of seed coat. The later was confirmed by scarification of seed coat which resulted in 53% increase in seed weight against 0% in control. Further, presence of a potent toxin (abrin) in the seed coat protects it from pests and microbes, and contributes to the maintenance of impermeability for longer period of time. The data validates the use of A. precatorious seeds as a weighing unit (ratti) by the indigenous people and discussed.

scholarly journals Effects of Different Pretreatments and Seed Coat on Dormancy and Germination of Seeds of Senna obtusifolia (L.) H.S. Irwin & Barneby (Fabaceae)

2016 ◽  
Vol 8 (2) ◽  
pp. 77
Author(s):  
Stephen I. Mensah ◽  
Chimezie Ekeke
Keyword(s):  
Sulfuric Acid ◽  
Seed Dormancy ◽  
Water Uptake ◽  
Seed Coat ◽  
Critical Factor ◽  
Potassium Nitrate ◽  
Ex Situ ◽  
Mechanical Resistance ◽  
Physical Dormancy ◽  
Senna Obtusifolia

<p class="1Body">The seed dormancy of <em>Senna obtusifolia</em> was investigated through various methods, namely pretreatments in concentrated sulfuric acid, 2% potassium nitrate (KNO<sub>3</sub>), 99% ethanol, 99% methanol, and in hydrogen perioxide; examination of the seed coverings; and the determination of water uptake by the seeds in order to ascertain the most effective technique for breaking dormancy and also determine the dormancy type. The results showed that sulfuric acid treatment recorded the highest germination (100%); followed by 2% hydrogen peroxide treatment (24%) in 15minutes immersion. The methanol and ethanol pretreatments gave 18.33% and 16.5% germinations respectively. Pretreatment in 2% potassium nitrate gave the lowest germination (8.50%), while the intact seeds of <em>S. obtusifiolia</em> (control) gave 0% germination. The anatomy of the seed coat indicated the presence of hard, thickened and specialized cells of cuticle, macrosclereids, osteoscereids, and disintegrated parenchyma layers. The water uptake of intact seeds was low (13.5%) after 24 hr imbibitions. These findings revealed that the seed coat acts as barrier to germination by preventing water absorption, possibly gaseous diffusion in and out of the seed and conferring mechanical resistance to the protrusion of embryo. Pretreatments, such as immersion in H<sub>2</sub>SO<sub>4 </sub>will soften the seed coat and permit germination. Seed dormancy in <em>S. obtusifolia </em>can be considered of physical nature and classified as physical dormancy. The results obtained in this study may serve as useful information in the production and improvement of <em>S. obtusifolia </em>seedlings, as knowledge on seed dormancy and germination is a critical factor and requirements to the understanding of the propagation of this plant either in situ or ex-situ, in view of the economic potentials/attributes of this species.</p>

scholarly journals Roles of Glutathione in Mediating Abscisic Acid Signaling and Its Regulation of Seed Dormancy and Drought Tolerance

Genes ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1620
Author(s):  
Murali Krishna Koramutla ◽  
Manisha Negi ◽  
Belay T. Ayele
Keyword(s):  
Signal Transduction ◽  
Abscisic Acid ◽  
Seed Dormancy ◽  
Growth And Development ◽  
Current Knowledge ◽  
Stomatal Closure ◽  
Redox Homeostasis ◽  
Critical Role ◽  
Stress Conditions ◽  
Signal Perception

Plant growth and development and interactions with the environment are regulated by phytohormones and other signaling molecules. During their evolution, plants have developed strategies for efficient signal perception and for the activation of signal transduction cascades to maintain proper growth and development, in particular under adverse environmental conditions. Abscisic acid (ABA) is one of the phytohormones known to regulate plant developmental events and tolerance to environmental stresses. The role of ABA is mediated by both its accumulated level, which is regulated by its biosynthesis and catabolism, and signaling, all of which are influenced by complex regulatory mechanisms. Under stress conditions, plants employ enzymatic and non-enzymatic antioxidant strategies to scavenge excess reactive oxygen species (ROS) and mitigate the negative effects of oxidative stress. Glutathione (GSH) is one of the main antioxidant molecules playing a critical role in plant survival under stress conditions through the detoxification of excess ROS, maintaining cellular redox homeostasis and regulating protein functions. GSH has recently emerged as an important signaling molecule regulating ABA signal transduction and associated developmental events, and response to stressors. This review highlights the current knowledge on the interplay between ABA and GSH in regulating seed dormancy, germination, stomatal closure and tolerance to drought.

scholarly journals Effects of constant incubation regimes on eggs and hatchlings of the egg-laying skink, Oligosoma suteri

2021 ◽  
Author(s):  
◽  
Kelly Maree Hare
Keyword(s):  
Hatching Success ◽  
Incubation Temperature ◽  
Unit Length ◽  
Condition Index ◽  
Egg Laying ◽  
Maternal Influence ◽  
Temperature Dependent ◽  
Sprint Speed ◽  
Fitness Traits ◽  
Incubation Temperatures

<p>The conditions under which reptilian eggs are incubated affect survival probability and physiological attributes of the progeny. The egg-laying skink, Oligosoma suteri, is the only endemic oviparous lizard in New Zealand. No controlled laboratory incubation had previously been undertaken, and thus no information was available on the requirements for successful captive incubation. I studied the effects of incubation regime on the eggs and hatchlings of O. suteri to four months of age. Oligosoma suteri eggs (n = 174) were randomly distributed among three constant incubation temperatures (18°C, 22°C and 26°C) and two water potentials (-120 kPa and -270 kPa). Hatching success and hatchling survival were greatest at 22°C and 26°C, with hatchlings from 18°C incubation suffering from physical abnormalities. Incubation regime and maternal influence did not affect sex of individuals, with equal sex ratios occurring from each incubation treatment. Hatchlings from the 22°C and -120 kPa incubation treatments were larger, for most measurements, and warmer incubation temperatures resulted in increased growth rates. Juveniles from 22°C and 26°C and individuals with greater mass per unit length (condition index) sprinted faster over 0.25 m. Sprint speed was positively correlated with ambient temperature. At four months of age sprint speed decreased in 18°C individuals and individuals incubated at 26°C and -270 kPa compared to their performance at one month. The results suggest that the most successful captive incubation regime for O. suteri is 22°C and -120 kPa. This study also shows that temperature-dependent sex determination does not occur in O. suteri, but that fitness traits are influenced by incubation temperature.</p>

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