Ultrastructural Changes in Cells of Pea Embryo Radicles During Germination

Yoo, Bong Y.

doi:10.1083/jcb.45.1.158

Cited by 78 publications

(41 citation statements)

References 31 publications

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“…during germination, and perhaps also during dehydration. A similar association has previously been noted, for example, in plastids of elongating pollen tubes (Larson, 1965) and in radicles of germinating Pisum sativum (Perner, 1965;Yoo, 1970). E.R.…”

Section: Discussionmentioning

confidence: 71%

CHLOROPLAST DEVELOPMENT IN PRIMARY LEAVES OF PHASEOLUS VULGARIS

Whatley¹

1974

New Phytologist

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SUMMARYChanges in plastid ultrastructure in the primary leaves of Phaseolus vulgaris were followed during the period of seed development and, following a period of dormancy, throughout the life span of the leaf from germination to senescence. The total life span of the leaf was about 14 weeks. During this time the plastid remained as a proplastid for about 7 weeks. Following germination, synchronous developmental changes associated with lamellar production, which lasted for a period of i week, resulted in the change of the proplastid into a mature chloroplast. This mature chloroplast was characteristic of the subsequent period of 2 weeks, then changes in plastid shape and in the lamellar alignment led eventually to senescence some 3-4 weeks later. The period of rapid synchronous development during the week following germination was observed in detail and a comparison made with plastid development in plants grown in continuous darkness. Three transitory stages were consistently observed between other more persistent and generally recognized plastid developmental stages. The first occurs when the E.R. partially surrounds the proplastid during early germination; the second when the proplastid assumes an amoeboid configuration which is postulated as a precursor to various divergent plastid types; the third occurs between the developing plastid with perforated stroma lamellae and incipient grana and the mature chloroplast with continuous aligned lamellae and stacked grana.

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Section: Discussionmentioning

confidence: 71%

CHLOROPLAST DEVELOPMENT IN PRIMARY LEAVES OF PHASEOLUS VULGARIS

Whatley¹

1974

New Phytologist

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“…The cytoplasm contains free ribosomes, but few or no free polysomes can be detected. The mitochondria have a simplified structure with an electronopaque matrix and few cristae (1,7,8,11,17). The respiration rate of air-dry seeds has been measured manometrically in a respirometer and is of the order of 100 ul h-' g-' dry weight (Qo2Qco.).…”

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confidence: 99%

Metabolism As a Function of Water Potential in Air-Dry Seeds of Charlock (Sinapis arvensis L.)

Edwards¹

1976

Plant Physiol.

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A new method is described for studying the metabolism of air-dry seeds. An initial pulse of '4CO2 was supplied to seeds maintained in air at controDled low water potentials for 6 months. Seeds were also infltrated with 2-'4C-acetate and with 14C-L-leucine at 0 C, redried rapiDly at 0 C, and maintained at controlled low water potentials for 4 to 6 weeks. The metabolism of the air-dry seeds was a function of the water content of the tissues, which was in equilibrium with the water potential at the seed surface. The fixation of 14CO2 and the utilization of 2-'4C-acetate increased exponentialy with water content. The incorporation of 14C-Lleucine into protein increased linearly with water content. Metabolism was not reduced to a low rate except in air-dry seeds at the lowest water potentials (-1716 to -762 bars) with 4 to 6% water.During the last phase of seed development and dehydration, structural changes occur in the embryo axis and storage tissues associated with loss of water and reduction in rate of metabolism. The cells and organelles show signs of shrinkage and possibly alteration of membrane structure and permeability. The rough endoplasmic reticulum is reduced to a small number of crescent layers in the region of organelles and the plasmalemma. The cytoplasm contains free ribosomes, but few or no free polysomes can be detected. The mitochondria have a simplified structure with an electronopaque matrix and few cristae (1,7,8,11,17). The respiration rate of air-dry seeds has been measured manometrically in a respirometer and is of the order of 100 ul h-' g-' dry weight (Qo2Qco.). The rate increases exponentially with water content, with critical values for acceleration above the water status of air-dry seeds (1, 2, 12, 15). Evidence for in vivo protein synthesis in air-dry seeds has been published by Chen (4, 5). Seeds of Avena fatua L. exposed to traces of 14C-ethanol vapor at 23 C for 1 week incorporated a significant amount of radioactivity into ethanol-insoluble residues, from which labeled amino acids were released by hydrolysis with 6 N HCI at 105 C for 18 hr or by incubation with pronase. Marcus (10) was unable to detect protein synthesis in dry wheat embryos after exposure for 19 min to 14C-leucine. Extracts (13,14). Protein synthesis in air-dry seeds apparently occurs using stored mRNA (9, 10) (Payne and Gordon, personal communication). The results of this communication show that the rate of mitochondrial activity and protein synthesis in air-dry seeds is a function of the water content of the tissues, which is in equilibrium with the water potential of the atmosphere at the seed surface. MATERIALS AND METHODSSupply of 14C to Seeds at Low Water Potentials. Charlock (Sinapis arvensis L.) seeds were surface sterilized in 96% ethyl alcohol for 5 min and dried for 1 hr under UV light. Samples of 50 seeds were placed in thin-walled polypropylene cups which were suspended with nichrome wire from the rubber caps of small glass vials under sterile conditions. The water potential at the seed sur...

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“…Single-membranes were also reported for lipid bodies in pea seeds (Yoo, 1970) and lipid storage vacuoles in the cotyledons of Cucurbita maxima (Lott et al, 1971). …”

Section: Membranementioning

confidence: 99%

“…The data suggested either that the plasma and plastid membranes become similar (in the sense that they bind or attract the composite lipid); or that two classes of composite lipid vesicles exist such that one class binds to the plasma membrane, and the other binds to the plastid membrane. In another study, lipid bodies in pea seeds were found closely packed against each other and confined to regions near the cell surface or near plastids in radicles of dormant, 80 minute, 8 and 12 hour embryos (Yoo, 1970). Sorokin and Sorokin (1966) reported that in tissues from Campanula persicifolia L., spherosomes were distributed throughout the tissue and appeared singly, in twos or in more numerous groupings.…”

Section: Membranementioning

confidence: 99%

“…However, Saio and Watanabe (1966) found no membraneous material. Membrane-bound protein bodies are prevalent in many other plant tissues and have been reported in a number of cotyledonary tissues similar to soybeans (Jones, 1969;Lott et al, 1971;Yatsu, 1965;Yoo, 1970). Tombs (1967) suggested that the membrane delimiting the soybean protein body (estimated at 75 k in thickness), consisted of phospholipids.…”

Section: Subcellular Components Protein Bodiesmentioning

confidence: 99%

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Microscopy of soybean seeds: cellular and subcellular structure during germination, development and processing with emphasis on lipid bodies

Bair

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Ultrastructural Changes in Cells of Pea Embryo Radicles During Germination

Cited by 78 publications

References 31 publications

CHLOROPLAST DEVELOPMENT IN PRIMARY LEAVES OF PHASEOLUS VULGARIS

CHLOROPLAST DEVELOPMENT IN PRIMARY LEAVES OF PHASEOLUS VULGARIS

Metabolism As a Function of Water Potential in Air-Dry Seeds of Charlock (Sinapis arvensis L.)

Microscopy of soybean seeds: cellular and subcellular structure during germination, development and processing with emphasis on lipid bodies

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