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

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.

1975 ◽  
Vol 53 (24) ◽  
pp. 3041-3050 ◽  
Author(s):  
C. H. A. Little

In experiments with attached and detached shoots of balsam fir, Abies balsamea L., synthetic (±)abscisic acid (ABA) (1) reduced photosynthesis and transpiration by inducing stomatal closure, (2) inhibited indoleacetic acid (IAA) - induced cambial activity in photosynthesizing and non-photosynthesizing shoots, and (3) inhibited the basipetal movement of [14C]IAA. Neither gibberellic acid nor kinetin counteracted the inhibitory effect of (±)ABA on IAA-induced cambial activity. In addition it was demonstrated that increasing the internal water stress increased the level of endogenous ABA in the phloem–cambial region of bark peelings and decreased the basipetal movement of [14C]IAA through branch sections. On the basis of these findings it is proposed that internal water stress inhibits cambial activity, partly through increasing the level of ABA; the ABA acts to decrease the provision of carbohydrates and auxin that are required for cambial growth.


1974 ◽  
Vol 82 (1) ◽  
pp. 113-116 ◽  
Author(s):  
M. Abdel-Rahman ◽  
F. M. R. Isenberg

SUMMARYExperiments were conducted to study the effect of plant injection with growth regulators on the dormancy of onion bulbs cv. Elba Globe. Application of abscisic acid induced early senescence of the leaves and prolonged the rest period of the bulbs. This effect was partially overcome by subsequent applications of gibberellin, auxin or cytokinin and totally overcome with the application of a mixture of the three hormones. Maleic hydrazide application prolonged the rest period by inhibiting both sprouting and rooting of the bulbs throughout the storage period. This inhibitory effect was not overcome by the subsequent application of auxin, gibberellin, kinetin, or their combinations. Ethephon application increased rooting of bulbs and partially overcame the effect of abscisic acid on dormancy.


2011 ◽  
Vol 80 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Emilia Wilmowicz ◽  
Kamil Frankowski ◽  
Paulina Glazińska ◽  
Jacek Kęsy ◽  
Jan Kopcewicz

<p>Flowering of plants is controlled by hormones among which both stimulators and inhibitors are present. The role of abscisic acid (ABA) in flower induction of the short day plant <em>Pharbitis nil</em> was shown in our experiments through exogenous applications and endogenous level determination of the hormone in cotyledons of seedlings grown under special light conditions.</p><p>The application of ABA to cotyledons or shoot apices during the first half of a 24-h long inductive night inhibits flowering. The same compound applied towards the end of or after a 14-h long subinductive night increases the number of flower buds produced by these plants.</p><p>Exposing <em>P. nil</em> seedlings at the beginning of a 24-h long inductive night to far red light (FR) decreases the level of endogenous abscisic acid in cotyledons and leads to flower inhibition. However, a pulse of red light (R) reversing the inhibitory effect of far red light on the flowering of <em>P. nil</em> increases the ABA content.</p><p>The results obtained confirm previous observations that ABA may play a dual and an important role in the regulation of floral bud formation in <em>P. nil</em>. The flowering occurs when the level of endogenous abscisic acid is low at the beginning and is high toward the end of the inductive night.</p>


HortScience ◽  
1991 ◽  
Vol 26 (2) ◽  
pp. 175-177 ◽  
Author(s):  
Jocelyn A. Ozga ◽  
F.G. Dennis

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).


2012 ◽  
Vol 58 (No. 4) ◽  
pp. 181-185 ◽  
Author(s):  
A. Bano ◽  
F. Ullah ◽  
A. Nosheen

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;


1995 ◽  
Vol 5 (2) ◽  
pp. 61-73 ◽  
Author(s):  
Henk W. M. Hilhorst

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.


1978 ◽  
Vol 58 (3) ◽  
pp. 761-767 ◽  
Author(s):  
J. M. LEE ◽  
N. E. LOONEY

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.


2017 ◽  
Vol 28 (1) ◽  
pp. 1-7
Author(s):  
Analía B. Martínez ◽  
Verónica Lema ◽  
Aylen Capparelli ◽  
Fernando López Anido ◽  
Roberto Benech-Arnold ◽  
...  

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.


2020 ◽  
Vol 21 (13) ◽  
pp. 4607 ◽  
Author(s):  
Marta Gietler ◽  
Justyna Fidler ◽  
Mateusz Labudda ◽  
Małgorzata Nykiel

Abscisic acid (ABA) is well-known phytohormone involved in the control of plant natural developmental processes, as well as the stress response. Although in wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) its role in mechanism of the tolerance to most common abiotic stresses, such as drought, salinity, or extreme temperatures seems to be fairly well recognized, not many authors considered that changes in ABA content may also influence the sensitivity of cereals to adverse environmental factors, e.g., by accelerating senescence, lowering pollen fertility, and inducing seed dormancy. Moreover, recently, ABA has also been regarded as an element of the biotic stress response; however, its role is still highly unclear. Many studies connect the susceptibility to various diseases with increased concentration of this phytohormone. Therefore, in contrast to the original assumptions, the role of ABA in response to biotic and abiotic stress does not always have to be associated with survival mechanisms; on the contrary, in some cases, abscisic acid can be one of the factors that increases the susceptibility of plants to adverse biotic and abiotic environmental factors.


Author(s):  
Hong Lang ◽  
Yuting He ◽  
Fengcheng Li ◽  
Dianrong Ma ◽  
Jian Sun

AbstractWeedy rice is one of the most severe weeds in paddy fields, characterized by its high degree of seed shattering. Abscisic acid (ABA) serves as an abscission-accelerating signal and plays a critical role during abscission. However, mechanisms that link ABA and seed shattering remain elusive. In this study, WR04-6 (shattering) and SN9816 (non-shattering) were used to investigate the expression levels of genes involved in ABA biosynthesis and to determine the levels of ABA in tissues collected from the abscission zone (AZ) and the spikelet. ABA content in WR04-6, particularly in AZ, was significantly higher than in SN9816, significantly increasing prior to abscission. RNA-Sequencing and further expression analyses showed that the expression of OsNCED, the key gene involved in ABA biosynthesis, coincided with the increase of ABA content in the AZ and significantly increased during the seed shattering process. Additionally, the expression analysis of genes related to biosynthesis and metabolism of indole-3-acetic acid, gibberellin acid, and ethylene showed the greatest fold-change. Phytohormone levels associated with ABA co-expression-prediction revealed a potential signal transduction network among plant hormones involved in the regulation of seed abscission. Taken together, data presented in this study suggest that ABA contributes to seed shattering and transiently cooperates with other hormones, triggering a hormone imbalance that leads to the downstream activation of the AZ.


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