A function of the Golgi apparatus in polysaccharide synthesis and transport in the root-cap cells of wheat

Northcote, D. H.; Pickett‐Heaps, Jeremy D.

doi:10.1042/bj0980159

Cited by 351 publications

(113 citation statements)

References 30 publications

Supporting

Mentioning

101

Contrasting

Unclassified

Order By: Relevance

“…On the whole, within the entire incubation period, the number of dictyosomes does not differ significantly (P > 0.25, Table I) between the two treatments in both cell types. However, in the auxin-treated segments, the dictyosome number shows an initial decrease, followed by an increase, and another decrease, in both the outer epidermis and the parenchyma as compared to the control (Table I, (2,5,7,10,11,13,15,17,19,20). The present study adds further support to the ascribed function of the dictyosomes.…”

Section: Methodsmentioning

confidence: 99%

Effects of Indoleacetic Acid on Dictyosomes of Apical and Expanding Cells of Oat Coleoptiles

Gawlik

Shen-Miller²

1974

Plant Physiol.

View full text Add to dashboard Cite

We found that the auxin-induced growth is mediated through the activation of the dictyosomes (collectively, the Golgi apparatus). Incubation of oat (Avena sativa) coleoptile segments in indoleacetic acid-sucrose-phosphate buffer changes significandy the number of dictyosomes in the expanding cells. A further indication of auxin enhancement of dictyosome activity is a decrease in dictyosomal cisternae (flattened membranous sacs) number. This decrease occurred after 6 minutes of incubation in auxin, and then was followed by a reduction in the organelle number per se. These times are in keeping with the rapid action of auxin-induced cell elongaton, and the latent period of geotropism. In the apical cells, the effect of indoleacetic acid is more subtle and complex. The 3To whom reprint requests should be addressed.Individual stacks of cistemae (flattened sacs containing fluid). The association of dictyosomes within a cell forms the Golgi apparatus (14). regulated by the hormone auxin. In this study we ask whether auxin, IAA, changes the activity of the dictyosomes. And if so, are the kinetics of the changes in keeping with those of the tropistic and growth responses. We examined the quantity and activity of this organelle in the extreme apex as well as in the elongating cells of oat coleoptiles after different times of incubation in IAA solutions. MATERIALS AND METHODSPlanting and Incubation. Oat seeds (Avena sativa, Victory I) were soaked in warm tap water (initially 40 C) for 2 hr, drained, and kept in the dark for 20 hr at 4 C. The soaked seeds were then aligned, embryo up, on lucite bars covered with moist filter paper. The seeds were exposed to red light (G.E. Ruby Red tungsten filament lamp, 10 w) for 24 hr, and grown for an additional 48 hr in the dark. At the end of this period, the coleoptiles reached a length of 2 to 3 cm. The apical 1 mm, and the subapical 3 mm (4th through 6th mm) of the coleoptile were sectioned with spaced razor blades. The segments were placed in Petri dishes containing buffer, 0.1 M KH2PO4 and 2% sucrose (pH 4.6). The dishes were set on a slow reciprocating horizontal shaker for a minimum of 2 hr, in order to deplete the tissues of their endogenous auxin. The segments were then transferred to small culture dishes containing the same buffer solution with or without 1 ,M IAA (sodium salt). The dishes were then placed on the shaker, and the segments were harvested at 6-min intervals for a period of 60 min for examinations by EMS and for the determination of cell lengths. All manipulations were carried out in a dim green light (21) at 25 C and 70% relative humidity.Electron and Light Microscopy. At 6-min intervals, the segments (n = 6) were transferred to a cold fixative (approximately 4 C) containing 4% glutaraldehyde, 1 % acrolein buffered with 0.1 M Na-cacodylate to pH 7.4, and 0.1% CaCI2. Fixation was carried out in a refrigerator (4-6 C) overnight. The aldehyde-fixed segments were then washed with the same buffer in which they were fixed, and postfixed for 3 hr in cold 1 %...

show abstract

Section: Methodsmentioning

confidence: 99%

Effects of Indoleacetic Acid on Dictyosomes of Apical and Expanding Cells of Oat Coleoptiles

Gawlik

Shen-Miller²

1974

Plant Physiol.

View full text Add to dashboard Cite

show abstract

“…␣-1,4-Galacturonosyltransferase (GalAT) activity has been identified in numerous plants (12) and shown to be membrane-bound in all species studied. Work in pea localized HG:GalAT activity to the luminal side of Golgi vesicles (13), the same location as pectin synthesis (14,15). The most extensive study of HG:GalAT activity was done in tobacco (16,17), and characteristics of the tobacco enzyme are comparable with the activity described in other plant species.…”

mentioning

confidence: 99%

Functional identification of an Arabidopsis pectin biosynthetic homogalacturonan galacturonosyltransferase

Sterling

Atmodjo

Inwood

et al. 2006

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

242

312

View full text Add to dashboard Cite

Galacturonosyltransferases (GalATs) are required for the synthesis of pectin, a family of complex polysaccharides present in the cell walls of all land plants. We report the identification of a pectin GalAT (GAUT1) using peptide sequences obtained from Arabidopsis thaliana proteins partially purified for homogalacturonan (HG) ␣-1,4-GalAT activity. Transient expression of GAUT1 cDNA in the human embryonic kidney cell line HEK293 yielded uridine diphosphogalacturonic acid:GalAT activity. Polyclonal antibodies generated against GAUT1 immunoabsorbed HG ␣-1,4-GalAT activity from Arabidopsis solubilized membrane proteins. BLAST analysis of the Arabidopsis genome identified a family of 25 genes with high sequence similarity to GAUT1 and homologous genes in other dicots, in rice, and in Physcomitrella. Sequence alignment and phylogenetic Bayesian analysis of the Arabidopsis GAUT1-related gene family separates them into four related clades of GAUT and GAUT-like genes that are distinct from the other Arabidopsis members of glycosyltransferase family 8. The identification of GAUT1 as a HG GalAT and of the GAUT1-related gene family provides the genetic and biochemical tools required to study the function of these genes in pectin synthesis.biosynthesis ͉ cell wall ͉ glycosyltransferase ͉ polygalacturonic acid ͉ pectic polysaccharide

show abstract

“…Using several plant systems, including grass species, autoradiography and membrane fractionation showed that monosaccharides from 14 C-labeled substrates accumulated in cell wall polysaccharides in Golgi vesicles during a pulse were subsequently transferred to the cell wall when chased with unlabeled substrates (Northcote and Pickett-Heaps, 1966;Pickett-Heaps, 1967;Jilka et al, 1972). Early studies showed that labeled sugars from nucleotide-sugar substrates could be incorporated into alcohol-insoluble polysaccharides using microsomal membranes, and later refined by isolation of Golgi membranes and the synthesis of defined polysaccharides with combinations of nucleotide sugars (Bailey and Hassid, 1966;Ray et al, 1969Ray et al, , 1976Smith and Stone, 1973;Ray, 1980;Hayashi and Matsuda, 1981a;Gordon and Maclachlan, 1989;Gibeaut and Carpita, 1993).…”

mentioning

confidence: 99%

The Maize Mixed-Linkage (1→3),(1→4)-β-d-Glucan Polysaccharide Is Synthesized at the Golgi Membrane

Carpita

McCann

2010

Plant Physiology

View full text Add to dashboard Cite

With the exception of cellulose and callose, the cell wall polysaccharides are synthesized in Golgi membranes, packaged into vesicles, and exported to the plasma membrane where they are integrated into the microfibrillar structure. Consistent with this paradigm, several published reports have shown that the maize (Zea mays) mixed-linkage (1→3),(1→4)-β-d-glucan, a polysaccharide that among angiosperms is unique to the grasses and related Poales species, is synthesized in vitro with isolated maize coleoptile Golgi membranes and the nucleotide-sugar substrate, UDP-glucose. However, a recent study reported the inability to detect the β-glucan immunocytochemically at the Golgi, resulting in a hypothesis that the mixed-linkage β-glucan oligomers may be initiated at the Golgi but are polymerized at the plasma membrane surface. Here, we demonstrate that (1→3),(1→4)-β-d-glucans are detected immunocytochemically at the Golgi of the developing maize coleoptiles. Further, when maize seedlings at the third-leaf stage were pulse labeled with [14C]O2 and Golgi membranes were isolated from elongating cells at the base of the developing leaves, (1→3),(1→4)-β-d-glucans of an average molecular mass of 250 kD and higher were detected in isolated Golgi membranes. When the pulse was followed by a chase period, the labeled polysaccharides of the Golgi membrane diminished with subsequent transfer to the cell wall. (1→3),(1→4)-β-d-Glucans of at least 250 kD were isolated from cell walls, but much larger aggregates were also detected, indicating a potential for intermolecular interactions with glucuronoarabinoxylans or intermolecular grafting in muro.

show abstract

A function of the Golgi apparatus in polysaccharide synthesis and transport in the root-cap cells of wheat

Cited by 351 publications

References 30 publications

Effects of Indoleacetic Acid on Dictyosomes of Apical and Expanding Cells of Oat Coleoptiles

Effects of Indoleacetic Acid on Dictyosomes of Apical and Expanding Cells of Oat Coleoptiles

Functional identification of an Arabidopsis pectin biosynthetic homogalacturonan galacturonosyltransferase

The Maize Mixed-Linkage (1→3),(1→4)-β-d-Glucan Polysaccharide Is Synthesized at the Golgi Membrane

Contact Info

Product

Resources

About