Lysosomal nature of hormonally induced enzymes in wheat aleurone cells

Gibson, RA; Paleg, L. G.

doi:10.1042/bj1280367

Cited by 36 publications

(4 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The present experiments suggest that this type of ‘vacuole’ has a role in dormancy release. Our finding that they contain 1,3‐β‐ d ‐glucanases supports early enzyme studies indicating that spherosomes contain hydrolases (Matile, 1975) and have a lysosome‐like nature (Gibson and Paleg, 1972; Vigil and Ruddat, 1973). The observed connection between plasmodesmata and the spherosome‐like vacuoles could explain the removal of the plasmodesmal sphincters in birch.…”

Section: Discussionsupporting

confidence: 87%

The shoot apical meristem restores its symplasmic organization during chilling‐induced release from dormancy

2001

View full text Add to dashboard Cite

SummaryThe shoot apex of overwintering perennials ceases its morphogenetic activity at the end of the growing season and transforms into a bud which is dormant and freezing-tolerant. In birch (Betula pubescens) these events are triggered by short photoperiod, and involve the production of 1,3-b-D-glucan containing sphincters on the plasmodesmata. As a result, all symplasmic pathways shut down. Here we show that breakage of bud dormancy by chilling involves restoration of the symplasmic organization of the meristem. This restoration is likely to be mediated by 1,3-b-D-glucanase, which was present in small spherosome-like vacuoles that arose de novo during dormancy induction. During chilling these vacuoles were displaced from the bulk cytoplasm to the cortical cytoplasm where they became aligned with the plasma membrane, often associated with plasmodesmata. At this stage the enzyme also appeared outside the vacuoles. During chilling, 1,3-b-D-glucan disappeared from the plasmodesmal channels and wall sleeves, and the plasmodesmata regained the capacity for cell±cell transport, as demonstrated by microinjection of Lucifer Yellow CH and Fluorescein-tagged gibberellic acid. Collectively, the present experiments demonstrate that restoration of the symplasmic organization of the meristem is indispensable for the release of buds from dormancy and the assumption of a proliferation-competent state, and implicate 1,3-b-D-glucanase action at the plasmodesmata. Based on these ®ndings we propose a model for`dormancy cycling' which depicts the meristem as passing through three sequential states of cellular communication with characteristic sensitivities to distinct environmental cues.

show abstract

Section: Discussionsupporting

confidence: 87%

The shoot apical meristem restores its symplasmic organization during chilling‐induced release from dormancy

2001

View full text Add to dashboard Cite

show abstract

“…Thus, the aleurone tissue has an exocytotic function, secreting hydrolases, including a-amylase, in response to hormone (Filner et al, 1969). The secretory mechanism involves vesicular transport within the cell (Gibson & Paleg, 1972;Firn, 1975) leading to exocytosis through the plasmalemma (see Tomos & Laidman, 1979;Laidman, 1980). The synthesis and secretion of aamylase requires Ca2+ (Goodwin & Carr, 1972).…”

Section: Discussionmentioning

confidence: 99%

“…Evidence includes the facts that a-amylase isolated from aleurone tissue is lysosomal (Gibson & Paleg, 1972;Firn, 1975) and endomembrane flow from the endoplasmic reticulum into vesicles is induced by gibberellic acid (Colborne et al, 1976). might have conserved a similar hormone Involvement of the endomembrane system in the synthesis and secretion of a-amylase has led several groups of workers to study phospholipid metabolism in the aleurone tissue (see Laidman, 1982).…”

mentioning

confidence: 99%

Gibberellic acid-stimulated α-amylase secretion and phospholipid metabolism in wheat aleurone tissue

Mirbahar¹,

Laidman²

1982

Biochemical Journal

View full text Add to dashboard Cite

1. Turnovers of [14C]glycerol-labelled phospholipids in wheat aleurone tissue have been measured by using a pulse-decay technique. The most metabolically active phospholipids were phosphatidylcholine, phosphatidylinositol, phosphatidylethanolamine and phosphatidylglycerol. 2. Gibberellic acid action on the tissue led to breakdown of phosphatidylcholine and stimulated turnover of the other phosphatides concomitant with the secretion of alpha-amylase from the tissue. After pulse-labelling of the aleurone tissue with [14C]glycerol, radioactivity was lost from the phospholipids and appeared quantitatively in triacylglycerols, suggesting a stoichiometric metabolism of the former into the latter. Although 1,2-diacylglycerol is an expected intermediate in such a conversion, the patterns of radioactivity in diacylglycerols gave no indication of this. 3. Several aspects of the response of aleurone tissue to gibberellic acid resemble the responses of exocytotic animal tissues to external agonists. In particular, our results and previous reports in the literature suggest that endomembrane flow, exocytosis, phosphatidylinositol turnover and a requirement of Ca2+ for enzyme secretion are common to both plant and animal systems. Although considerable differences also exist between the two, the similarities are sufficient to warrant further consideration that plants and animals might have conserved a similar hormone response-secretion mechanism.

show abstract

“…Subcellular particles containing a-amylase, protease, and /?-amylase activity were obtained from wheat aleurone cells by Gibson and Paleg (7). However, as they did not provide data on the structure or composition of these particles, it is not known whether they are also spherosomes.…”

mentioning

confidence: 99%

Acid Hydrolases and Autolytic Properties of Protein Bodies and Spherosomes Isolated from Ungerminated Seeds of Sorghum bicolor (Linn.) Moench

Adams¹,

Novellie²

1975

Plant Physiol.

View full text Add to dashboard Cite

Lysosomal nature of hormonally induced enzymes in wheat aleurone cells

Cited by 36 publications

References 24 publications

The shoot apical meristem restores its symplasmic organization during chilling‐induced release from dormancy

The shoot apical meristem restores its symplasmic organization during chilling‐induced release from dormancy

Gibberellic acid-stimulated α-amylase secretion and phospholipid metabolism in wheat aleurone tissue

Acid Hydrolases and Autolytic Properties of Protein Bodies and Spherosomes Isolated from Ungerminated Seeds of Sorghum bicolor (Linn.) Moench

Contact Info

Product

Resources

About