Enzymic Degradation of Starch Granules in the Cotyledons of Germinating Peas

Juliano, Bienvenido O.; Varner, Joseph E.

doi:10.1104/pp.44.6.886

Cited by 121 publications

(53 citation statements)

References 17 publications

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“…1B). We anticipated finding a shift toward decreased mol wt as starches were degraded as has been reported for germinating pea seeds (14). The ratio of low-to-high mol wt starch from taproots of the HSt genotype averaged 0.23 (Fig.…”

Section: Starch Compositionmentioning

confidence: 85%

Composition and Structure of Starch from Taproots of Contrasting Genotypes of Medicago sativa L.

Fankhauser¹,

Volenec²,

Brown³

1989

Plant Physiol.

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The objective of this study was to examine the composition and branch chain lengths of alfalfa (Medicago sativa L.) The 12-KI absorbance properties of the low molecular weight starches from roots of the low starch genotype indicated that some branching may be present. The distribution of chain lengths from amylopectin did not change during starch degradation and reaccumulation for the high starch genotype. In the low starch genotype, the proportion of low molecular weight branches having a degree of polymerization between 1 and 30 was decreased at the very low starch concentrations observed on the 14th day of regrowth. Higher concentrations and/or quantities of starch in roots of the high starch genotype were not associated with greater rate of herbage regrowth, when compared to the low starch genotype.

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Section: Starch Compositionmentioning

confidence: 85%

Composition and Structure of Starch from Taproots of Contrasting Genotypes of Medicago sativa L.

Fankhauser¹,

Volenec²,

Brown³

1989

Plant Physiol.

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“…Starch is quantitatively the most abundant storage in seeds, and available evidence has indicated that seed starch is degraded in germination via the amylolytic pathway. 26 Therefore, HBCDs posed a severe inhibitory effect on seed germination most probably because they damaged the starch or depressed amylase activity.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Diastereomer-Specific Uptake, Translocation, and Toxicity of Hexabromocyclododecane Diastereoisomers to Maize

Wang

Huang

et al. 2012

J. Agric. Food Chem.

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Hexabromocyclododecane (HBCD), a brominated flame retardant, has become a ubiquitous contaminant due to its wide application, persistence, and toxicity. HBCD diastereoisomers have different physical and chemical properties and may differ in their bioaccumulation and toxicity in plants. Accumulation and toxicity of α-, β-, and γ-HBCDs in maize were investigated in the present study. The accumulation was in the order β-HBCD > α-HBCD > γ-HBCD in roots and β-HBCD > γ-HBCD > α-HBCD in shoots. Both the inhibitory effect of the diastereoisomers on the early development of maize and the intensities of hydroxyl radical and histone H2AX phosphorylation in maize exposed to 2 μg L −1 HBCD followed the order α-HBCD > β-HBCD > γ-HBCD, indicating the diastereomer-specific oxidative stress and DNA damage in maize. It was further confirmed that the generation of reactive oxygen species was one, but not the only, mechanism for DNA damage in maize exposed to HBCDs.

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“…Attention was focused on carbohydrates since evidence is accumulating that at least one role of GA3 in germination and development of many seeds involves the breakdown of starch (1,5).…”

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confidence: 99%

Metabolically Active Glucosides in Oleaceae Seeds

et al. 1970

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The seeds of six woody species of Oleaceae representing three genera, contain high concentrations of water-soluble glucosides, with major absorption maxima below 240 nanometers. In Fraxinus americana seeds three of these compounds, designated GL-3, GL-5, and GL-6, account for almost 10% of the dry weight. They are found in the endosperm and embryo but not in the pericarp. While the level of GL-5 is not particularly influenced by the physiological state of the embryo, that of GL-3 and GL-6 decreases as a result of germination and growth during a 10-day period. As the concentrations of GL-3 and GL-6 decrease, new ultraviolet-absorbing compounds are formed. The changes in the concentration of the ultraviolet-absorbing glucosides during cold temperature after-ripening, prior to germination, are small. When germination of dormant embryos is induced with gibberellic acid, the concentrations of GL-3 and GL-6 decrease in a manner similar to that observed with nondormant embryos. In the presence of abscisic acid no losses of GL-3 and GL-6 were observed. It is suggested that GL-3 and GL-6 fulfill some definite functions in the germination and growth of F. americana embryos, and that gibberellic acid and abscisic acid can exert a regulatory effect on the metabolism of these glucosides.The germination of white ash seeds, Fraxinus americana, normally requires the breaking of dormancy through cold temperature after-ripening. Embryos excised from dormant seeds will not germinate at 22 C under the same conditions that permit germination of embryos from nondormant seeds. Gibberellins and cytokinins allow germination and growth of dormant embryos while ABA' prevents these processes (9). The endogenous levels of the latter hormone reflect the physiological states of the embryos, lower levels being found in nondormant seeds (10).To gain insight into the mode of actions of these hormones, the changes in certain storage nutrients during germination of F. americana seeds were followed, and the effects of exogenously added GA3 and ABA were determined. Attention was focused on carbohydrates since evidence is accumulating that at least one role of GA3 in germination and development of many seeds involves the breakdown of starch (1, 5).Examination of dry F. americana seeds showed that while they are free of starch they do contain high concentrations of water-1 Abbreviations: ABA: abscisic acid; TLC: thin layer chromatography.soluble, ultraviolet-absorbing, dialyzable glucosides. Three of these glucosides, designated GL-3, GL-5, and GL-6-to indicate that they are glucosides and can be distinguished by their R, values-have been purified sufficiently to permit structural work. The quantitative determination of the glucosides is based on their intense absorption near 240 nm and purification by TLC. This method has been used to determine the distribution of GL-3, GL-5, and GL-6 in six species, representing three genera of the Oleacea family. Changes in concentration of the glucosides in F. americana seeds as a function of cold temperat...

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Enzymic Degradation of Starch Granules in the Cotyledons of Germinating Peas

Cited by 121 publications

References 17 publications

Composition and Structure of Starch from Taproots of Contrasting Genotypes of Medicago sativa L.

Composition and Structure of Starch from Taproots of Contrasting Genotypes of Medicago sativa L.

Diastereomer-Specific Uptake, Translocation, and Toxicity of Hexabromocyclododecane Diastereoisomers to Maize

Metabolically Active Glucosides in Oleaceae Seeds

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