Origin and Continuity of Cell Vacuoles

Buvat, Roger

doi:10.1007/978-3-540-36396-5_5

Cited by 36 publications

(9 citation statements)

References 49 publications

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“…Electron microscopy suggests that vacuolar dynanaism is a feature of actively metabolizing cells where small cytosolic vesicles constantly fuse to and separate from the larger vacuoles (Matile, 1978). The origin of these small membrane-bound vesicles may be the endoplasmic reticula (the site of plant cytochrome P-450), golgi apparatus or plasmalemma (Buvat, 1971); such vesicles, but not the optically-empty vacuoles, can be detected in the youngest meristematic tissue before the development of vacuoles proper (Buvat, 1971;Cutter, 1978). These vesicles, or provacuoles, are features of root cap cells, radicle and apical meristems and zones immediately behind these meristems (Buvat, 1971;Matile, 1978).…”

Section: The Alternative To Enzymic Detoxificationmentioning

confidence: 99%

“…The origin of these small membrane-bound vesicles may be the endoplasmic reticula (the site of plant cytochrome P-450), golgi apparatus or plasmalemma (Buvat, 1971); such vesicles, but not the optically-empty vacuoles, can be detected in the youngest meristematic tissue before the development of vacuoles proper (Buvat, 1971;Cutter, 1978). These vesicles, or provacuoles, are features of root cap cells, radicle and apical meristems and zones immediately behind these meristems (Buvat, 1971;Matile, 1978). Such tissues, which lack vacuole profiles (Matile, 1978), form the bulk of the seedling tissue.…”

Section: The Alternative To Enzymic Detoxificationmentioning

confidence: 99%

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Why Do Plants Have Cytochrome P‐450? Detoxification Versus Defence

Hendry

1986

New Phytologist

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SUMMARYEvidence is presented which suggests that cytochrome P-450, in plants, probably functions as in all other eukaryotic organisms, principally as a detoxification mechanism. In plants this function is largely suppressed during tissue maturation coinciding with cell vacuolation. The consequential accumulation and isolation of potential toxins within vacuoles provides higher plants with an anti-herbivore defence of evolutionary significance.

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Section: The Alternative To Enzymic Detoxificationmentioning

confidence: 99%

Section: The Alternative To Enzymic Detoxificationmentioning

confidence: 99%

Why Do Plants Have Cytochrome P‐450? Detoxification Versus Defence

Hendry

1986

New Phytologist

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“…Vacuole genesis is a lysosomal multistep rocess: (i) GERL (Golgi-associated Endoplasmic Reticulum from which Lysosomes apparently form) produces provacuoles into which lysosomal enzymes and probably other materials appear to be concentrated and packaged; (ii) GERL-derived provacuoles cooperate to drive a programmed cellular autophagy leading to young vacuoles; and (iii) the young vacuoles swell and fuse together into a few large mature vacuoles which continue to collect the GERL-derived provacuoles throughout the life of the cell.Although vacuoles are the most conspicuous membranebounded organelles in differentiated plant cells and their biochemical characterization is in progress (1, 2), the question of their origin is unsettled despite many light and electron microscopy studies (3)(4)(5). This report describes the use of marker enzyme activities and electron microscopy, at conventional as well as very high voltage, to investigate the pattern of vacuolation in root meristematic cells.…”

mentioning

confidence: 99%

Cytochemical studies on GERL, provacuoles, and vacuoles in root meristematic cells of Euphorbia

Marty

1978

Proc. Natl. Acad. Sci. U.S.A.

161

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The genesis of plant vacuoles has been studied by high-voltage and conventional electron microscopy. Vacuole genesis is a lysosomal multistep rocess: (i) GERL (Golgi-associated Endoplasmic Reticulum from which Lysosomes apparently form) produces provacuoles into which lysosomal enzymes and probably other materials appear to be concentrated and packaged; (ii) GERL-derived provacuoles cooperate to drive a programmed cellular autophagy leading to young vacuoles; and (iii) the young vacuoles swell and fuse together into a few large mature vacuoles which continue to collect the GERL-derived provacuoles throughout the life of the cell.Although vacuoles are the most conspicuous membranebounded organelles in differentiated plant cells and their biochemical characterization is in progress (1, 2), the question of their origin is unsettled despite many light and electron microscopy studies (3)(4)(5). This report describes the use of marker enzyme activities and electron microscopy, at conventional as well as very high voltage, to investigate the pattern of vacuolation in root meristematic cells. The results emphasize the role of GERL* in the origin of vacuoles and establish the sequence of related lysosomal events. They suggest that the plant vacuome is an intracellular digestive system involved in cellular autophagy and in internal membrane flow.MATERIAL AND METHODS Germination. Seeds of Euphorbia characias L. harvested locally from wild plants were sterilized in 10% commercial bleach for 30 min. The seeds were rinsed, soaked for 18 hr. and then placed in petri plates on filter paper moistened with deionized water. As soon as the root emerged, the seedlings were selected, transferred to a humid atmosphere, and grown vertically at room temperature (220) in the dark. When the root reached 10 ± 2 mm, the seedlings were collected for processing for electron microscopy.Morphological Studies. Whole seedlings were quickly immersed in an ice-cold fixative containing either 3% glutaraldehyde/0. 1 M cacodylate buffer, pH 7.4 or 2.5% glutaraldehyde/2% formaldehyde (prepared from paraformaldehyde immediately before use)/0.09 M cacodylate buffer, pH 7.4. After 30 min, 1.5-mm apical root tips were excised while in fixative, left immersed for an additional 90 min, and then processed as usual for observation by electron microscopy.Enzyme Activities. Preliminary processing included a short fixation in gfutaraldehyde or glutaraldehyde/formaldehyde followed by thorough rinses in 0.1 M cacodylate buffer (pH 7.4). Root tips were generally cut axially and, in each experiment, some tips were sectioned with the Sorvall TC 2 tissue chopper at approximately 50 Am. Specimens were collected in cold 0.1 M cacodylate buffer containing 0.22 M sucrose and then washed again with quick changes in graded buffers from pH 7.4 to 5.0 and finally in a citrate buffer (pH 4.8) to remove calcium salts. The pieces were incubated at 370 freely floating in acid phosphatase (EC 3.1.3.2) medium according to Novikoff (8, 9) or in Bell and Barrnett medium for t...

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“…These configurations suggest that lomasomes may be involved in vacuole formation. Observations indicating such functions, have been documented in growing plant cells, where vacuoles seem t o originate from plasma membrane invaginations (BUVAT 1971). Some of the structures (Fig.…”

Section: A K Balmentioning

confidence: 81%

Studies in the Quiescent Root Meristem of the Bulb of Allium Cepa L.: Fine Structure and Dna Synthesis *

Bal¹

1973

Dev Growth Differ

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Study of the quiescent root meristem of Allium cepa L. bulbs has revealed that its histological organization does not differ significantly from the growing meristem, except for the fact that the cells are all arrested in interphase. Ultrastructure of the quiescent tissue is, however, different in the organization of the nucleolus and in the absence of prominent endoplasmic reticulum, microtubules and golgi complexes.A variety of lomasome-like structures, plasma membrane modifications and vacuoles have been recorded. Most of the cells except for the ones in the root cap and quiescent center are highly vacuolated; vacuolation is maximum in the cortical zone of the meristem. The pattern of 'H thymidirie incorporation during early stages of sprouting indicates that asynchrony of the mitotic cycle, which is the characteristic of the growing mcristeni, is maintained during quiescence by the arrest of nuclei at different subphases of interphase.The base of the Allium cepa L., bulb is characteriscd by the presence of well differentiated quiescent root meristcms. Upon soaking, these meristems develop and grow, resulting in ;I number of adventitious roots. T h e cells of thc meristems in the 'air dry' bulb are in a state of imposed dormancy, possibly due t o lack of water. However, in some varitics t h e condition seems t o be closer t o true dormancy, and the bulbs fail t o sprout even when t h e environmental conditions are fulfilled.The growing root meristems of onion bulbs have been extensively used for the study of cell division and related problems a t both optical and electron microscope lcvels ( K i :~~r c : o T r 1904, PATALI and SWII

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Origin and Continuity of Cell Vacuoles

Cited by 36 publications

References 49 publications

Why Do Plants Have Cytochrome P‐450? Detoxification Versus Defence

Why Do Plants Have Cytochrome P‐450? Detoxification Versus Defence

Cytochemical studies on GERL, provacuoles, and vacuoles in root meristematic cells of Euphorbia

Studies in the Quiescent Root Meristem of the Bulb of Allium Cepa L.: Fine Structure and Dna Synthesis *

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