Respiration and Protein Synthesis in Dormant and After-ripened Seeds of <i>Avena fatua</i>

Chen, Shepley S. C.; Varner, Joseph E.

doi:10.1104/pp.46.1.108

Cited by 53 publications

(14 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nevertheless, it is apparent that GA3 was able to cause seed germination by stimulating both the axial and cotyledonary growth, resulting in the slight increase of its abnormality (Table V). These data would support the recent view (2,(4)(5)(6) that GA3-induced biogenesis at hydrolytic enzyme may not be the primary action of GA3 in the stimulation of seed germination.…”

Section: Discussionsupporting

confidence: 88%

Dormancy and Impotency of Cocklebur Seeds

1977

View full text Add to dashboard Cite

Germination of nondormant but impotent small cocklebur seeds (Xanthium pennsylvanicum Walr.) was promoted profoundly with thiourea or benzyladenine, and slightly with gibbereUlic acid. GibbereUic acid was ineffective in causing the germination of dormant cocklebur seeds, although thiourea and benzyladenine were effective. Experiments with excised seed pieces showed that the promotive effects of thiourea, benzyladenine, and gibbereUlic acid on cocklebur seed germination were associated with the enhancement of growth of seed parts; thiourea stimulated predominantly the axial growth, whereas benzyladenine stimulated predominantly the cotyledonary growth.Potassium nitrate or indoleacetic acid had little effect on the initial growth of either axes or cotyledons. Except for gibberellic acid, all of the compounds employed enhanced ethylene production, but in general, the ethylene production seemed more likely to be a consequence of growth rather than a cause of it. We conduded that the chemical regulation of seed germination may be a consequence of the alteration of growth capabilities in either the axes or cotyledons, or both.In a previous paper (10), we observed that cocklebur seeds respond in different manners to various germination stimulators: seeds treated with TU' or CO2 exhibited normal germination, but 02 enrichment caused germination in which the seed coat was mostly broken at the cotyledonary side rather than at the axial end. On the other hand, the seeds germinated with BA, C2H4, and GA3 exhibited an intermediate pattern in which approximately half of the germinations were normal. Granting that seed germination in dicot plants is a phenomenon occurring when the axis and the cotyledons generate enough thrust to overcome the restraint by the seed coat (8), these diverse response patterns might result from the differential growth responsiveness of the axis and cotyledon: for example, TU could preferentially enhance growth of the embryonic axis proper, whereas BA could more greatly enhance growth of the cotyledons and hence the abnormal lateral breaking of the seed coat. We have previously presented some evidence that C2H4, unlike CO2, strongly stimulates both the axial and cotyledonary growth (7).These findings caused us to examine the relative effectiveness of various known germination stimulators (15), such as TU, KNO3, BA, GA3, and IAA, in stimulating the growth of axial and cotyledonary seed pieces. Experiments were also directed toward a comparison between the dormant and nondormant seeds in response to these stimulators.' Abbreviation: TU: thiourea. MATERIALS AND METHODSSeeds of cocklebur (Xanthium pennsylvanicum Wallr.) were used in this experiment. For germination tests, dormant small seeds newly harvested in 1973, and the nondormant but impotent small seeds fully after-ripened since 1972 were exposed to various drugs on two filter paper discs in 5-cm Petri dishes with 2 ml water. For growth tests, the embryonic axis and cotyledon segments were excised from large seeds according to the procedur...

show abstract

Section: Discussionsupporting

confidence: 88%

Dormancy and Impotency of Cocklebur Seeds

1977

View full text Add to dashboard Cite

show abstract

“…In vivo labeling experiments of dormant versus nondormant imbibed seeds have generally shown that protein synthesis occurs at similar levels, at least until visible germination (2)(3)(4)10). Contrary to these findings, Mitchell and Villiers (14) reported that light was required for polysome formation in imbibed seeds displaying light-controlled dormancy.…”

mentioning

confidence: 59%

Polysome Formation in Light-sensitive Common Purslane Seeds

Reger¹,

Egley²,

Swanson³

1975

Plant Physiol.

View full text Add to dashboard Cite

Common purslane (Portulaca oleracea L.) seeds show lightcontrolled dormancy. Ribosome profiles from dark-incubated seeds consist of 22 to 26% polysomes. Light induces germination and stimulates polysome formation during the 12-hour lag period preceding radicle protrusion. Polysome levels increase to 29, 35, and 41 % with exposure to 3, 6, and 9 hours of light, respectively. Although polysomes form on imbibition in the dark, 6 hours of light stimulates a significant increase in polysome formation which is probably related to early stages of radicle elongation.Although polysome formation on imbibition of seeds has been well established (1, 9, 11-13, 15, 18) The present investigation of polysome formation in common purslane seeds, which display light-controlled dormancy, was undertaken to compare polysome levels in dark-incubated dormant seeds with polysome levels in seeds exposed to the dormancy-breaking stimulus of light. Purslane seeds are similar to Grand Rapids lettuce seeds in that they remain dormant in the dark even though fully imbibed (5,7,17 incubated in a 15-cm Petri dish containing one blotter paper moistened with 17 ml of distilled H20. All seeds were prepared under a green safelight. Petri dishes were wrapped in aluminum foil and placed in a germinator at 35 C. After 24 hr, Petri dishes containing seeds to be light-treated were unwrapped and returned to the germinator, which was illuminated with daylight fluorescent tubes to 1000 lux. All seeds received this 24-hr dark pretreatment so that dark-germinated seeds, less than 4%, could be eliminated. Petri dishes set up for germination tests contained six cellulose nitrate circles randomly placed over the uniformly distributed seeds. Each circle of 15-mm diameter encircled an average of 54 seeds. Percentage of germination represents an average of six determinations from a single Petri dish. Germination is defined here as radicle protrusion. Twenty-four-hr dark-incubated seeds, although fully imbibed (5,7,17), showed a 12-hr lag period before germination after exposure to light. Ribosomes were prepared from 24-and 33-hr dark-incubated seeds and from seeds exposed to 3 hr, 6 hr, and 9 hr of continuous light after 24 hr of dark incubation. One gram of seeds (two Petri dishes) was used for each ribosomal profile.Ribosome Isolation. At various stages of incubation, seeds (2 g) were harvested and frozen in liquid N2. Frozen seeds were reduced to a powder with a mortar and pestle. Twenty-five milliliters of extraction medium was used per ribosome preparation. Ten

show abstract

“…However, dormant seeds are able to carry out many metabolic functions, including food interconversions, membrane synthesis, and organelle production (11). It has been concluded that seed dormancy is not a state of general inactivity, but must be due to some specific metabolic block (3). Furthermore (4).…”

Section: Resultsmentioning

confidence: 99%

Seed Aging: Chromosome Stability and Extended Viability of Seeds Stored Fully Imbided

Villiers¹

1974

Plant Physiol.

110

View full text Add to dashboard Cite

MATERIALS AND METHODS"Seeds" (fruits) of Lactuca sativa L. vars. Arctic King and Grand Rapids were obtained from Suttons Seeds Ltd., Reading, U. K. Batches of these seeds were placed in closed containers with separate vessels of sulfuric acid, water, or diluted sulphuric acid giving relative humidities of 0, 25, 50, 75, and 100% at 20 C in the container atmospheres (9). After 2 weeks, the moisture contents of the seed batches were determined, and the seeds were sealed into separate glass bottles. Other large batches of seeds from the same provenances were imbibed on moist filter papers in Petri dishes. These Petri dishes, together with the bottles of air-dry seeds, were placed in dark incubators maintained continuously at 30 C (Arctic King), and 25 C (Grand Rapids), in order to prevent germination of the imbibed batches of seeds.Fruits of Fraxinus americana L. were purchased from Vilmorin-Andrieux of Paris. Samples were brought to a range of moisture contents as described for the lettuce seeds. They were then sealed into bottles, and stored in the dark at 22 C. A large sample of fruits was imbibed by mixing with moist sand and stored at 22 C in the dark in order to prevent germination of the imbibed fruits (unpublished results).At the times stated in the results, seeds from these treatments were tested for germination under 40-w fluorescent daylight lamps at 22 C. Petri dishes of seeds which had been maintained continuously imbibed were simply brought out from the dark incubators, while samples of seeds from air-dry store were imbibed on moist filter papers in Petri dishes at the beginning of each germination test. Germination was scored as the emergence and geotropic curvature of the radicle.Chromosomes in 1-mm radicle tips of lettuce were ex-875 www.plantphysiol.org on May 12, 2018 -Published by Downloaded from

show abstract

Respiration and Protein Synthesis in Dormant and After-ripened Seeds of Avena fatua

Cited by 53 publications

References 10 publications

Dormancy and Impotency of Cocklebur Seeds

Dormancy and Impotency of Cocklebur Seeds

Polysome Formation in Light-sensitive Common Purslane Seeds

Seed Aging: Chromosome Stability and Extended Viability of Seeds Stored Fully Imbided

Contact Info

Product

Resources

About