Journal ArticleDOI
Carbohydrate concentrations and interactions in afterripening-responsive dormant Avena fatua caryopses induced to germinate by gibberellic acid
TLDR
In this article, it has been proposed that gibberellic acid (GA3) promotes germination by overcoming restrictions in sugar production and utilization in afterripening-responsive dormant caryopses.Abstract:
It has been proposed that gibberellic acid (GA3) promotes germination by overcoming restrictions in sugar production and utilization in afterripening-responsive dormant caryopses. While their germination rates were similar, germination commenced sooner in afterripened wild oat (Avena fatua L.) caryopses than in dormant caryopses treated with GA3 and dormant excised embryos treated with GA3 plus fructose (Fru). Limited germination occurred in dormant excised embryos cultured with GA3 alone. Carbohydrate concentrations were measured over time in dormant caryopses and excised embryos whose germination was induced with GA3 and GA3 plus Fru. The concentration of sucrose (Suc) in the endosperm declined prior to germination of dormant GA3-treated caryopses. Raffinose (Raf) family oligosaccharides in the embryos of dormant GA-treated caryopses remained relatively constant prior to and shortly after the onset of germination. In contrast, Raf family oligosaccharides in the embryos of afterripened caryopses declined prior to germination. Together this suggests Raf family oligosaccharide utilization is not associated with germination per se. Increased starch levels, which occurred in dormant excised embryos treated with Fru and GA3 plus Fru, were associated with dormancy because similar effects were not apparent in afterripened embryos cultured with Fru. An initial decline in the concentration of Raf family oligosaccharides in dormant embryos cultured with GA3 or GA3 plus Fru seems to be a result of the excision process. GA3 appears to stimulate the germination of dormant embryos by enhancing the uptake or utilization of Fru. It appears that GA3 and afterripening-induced changes in carbohydrate utilization in dormant caryopses are different.read more
Citations
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Journal ArticleDOI
Biochemistry and physiology of raffinose family oligosaccharides and galactosyl cyclitols in seeds
TL;DR: The biochemistry and molecular biology of the enzymes of RFO and galactosyl cyclitol biosynthesis are focused on and the metabolic control and hormonal regulation of the pathway during seed development and germination is discussed.
Journal ArticleDOI
Temperature and Water Status of Seed Affect Afterripening in Wild Oat (Avena fatua)
TL;DR: Research was conducted to deter- mine the relationship between temperature and seed mois- ture levels on afterripening of dormant wild oat line M73.
Journal ArticleDOI
Cloning and characterization of differentially expressed genes in imbibed dormant and afterripened Avena fatua embryos
Bailin Li,Michael E. Foley +1 more
TL;DR: DNA sequence analyses indicated that some of the cDNA clones corresponding to genes that are differentially expressed in dormant and afterripened line M73 embryos encode LEA (late embryogenesis-abundant) proteins and aldose reductase.
Journal ArticleDOI
Soluble sugar content of white spruce (Picea glauca) seeds during and after germination.
Bruce Downie,J. Derek Bewley +1 more
TL;DR: Based on the similarity of sugar contents in seed parts between dormant and nondormant seeds that did not complete germination, differences in sugar metabolism are probably not the basis of dormancy in white spruce seeds.
Journal ArticleDOI
Metabolic control of embryonic dormancy in apple seed: seven decades of research
Stanislaw Lewak,Stanislaw Lewak +1 more
TL;DR: This review summarizes published data related to the modes of action of above factors on the changes in the levels of endogenous hormones and some other plant growth regulators, and on certain enzymes involved in mobilization of seed reserves and catabolism of their hydrolysis products.
References
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Journal ArticleDOI
Dormancy studies in seed of avena fatua: 2. a gibberellin-sensitive inhibitory mechanism in the embryo
J. M. Naylor,G. M. Simpson +1 more
TL;DR: The evidence presented here supports the view that control of germination during the period of after-ripening is through changes in inhibitor content rather than in endogenous gibberellin.
Journal ArticleDOI
Dormancy studies in seed of avena fatua: 3. a relationship between maltase, amylases, and gibberellin
G. M. Simpson,J. M. Naylor +1 more
TL;DR: The results lead to the conclusion that an important effect of gibberellic acid is to induce the synthesis of maltase or in some way activate the preformed enzyme.
Journal ArticleDOI
Variation Within Pure Lines of Wild Oats (Avena fatua) in Relation to Degree of Primary Dormancy
TL;DR: The germination of caryopses on water or GA3 solutions was used to characterize the degree of primary dormancy present in the seed progeny of 10 genetically pure lines of wild oats and identified several genetically in- herited characters that were associated with the inherited differences in degree ofPrimary dormancy.
Journal ArticleDOI
Dormancy studies in seed of avena fatua 4. : the role of gibberellin in embryo dormancy
TL;DR: The levels of free phosphate and specific activity of 3′-nucleotidase, and ability to synthesize soluble protein between 24 and 48 hours, are markedly restricted in highly dormant embryos and GA can overcome these restrictions.