Phytotropins. IV. Effect of Phytotropins on Cultured Plant Cells and Protoplasts

1982 ◽  
Vol 9 (3) ◽  
pp. 297 ◽  
Author(s):  
PJ Larkin ◽  
W Scowcroft ◽  
AE Geissler ◽  
GF Katekar
Keyword(s):  
Petunia Hybrida ◽  
Cultured Cells ◽  
Plant Cells ◽  
Dichlorophenoxyacetic Acid ◽  
Polar Transport ◽  
Suspension Cultured Cells ◽  
Specific Receptors ◽  
Nicotiana Debneyi ◽  
2,4 Dichlorophenoxyacetic Acid

The phytotropins l-(2'-carboxyphenyl)-3-phenylpropane-1,3-dione (CPP) and 5-(2-carboxyphenyl)- 3-phenylpyrazole (CPD) reduced the net efflux of radiolabel from suspension-cultured cells treated with [14C]2,4-dichlorophenoxyacetic acid when present at concentrations comparable to those that inhibit polar transport of auxins in bean petioles. These phytotropins stimulated division of protoplasts of both Nicotiana debneyi and Petunia hybrida at concentrations of exogenous auxins that were otherwise suboptimal for divisions. The results are consistent with the proposal that phytotropins interact with specific receptors to reduce auxin efflux, resulting in increased intracellular auxin concentrations.

The Transport Behaviour of the Synthetic Auxin 2,4-Dichlorophenoxyacetic Acid in Decapitated Seedlings of Sunflower (Helianthus annuus L.)

1982 ◽  
Vol 9 (1) ◽  
pp. 5 ◽  
Author(s):  
BT Brown ◽  
JN Phillips
Keyword(s):  
Transport System ◽  
Apical Dominance ◽  
Transport Process ◽  
Dichlorophenoxyacetic Acid ◽  
Loading Capacity ◽  
Polar Transport ◽  
Synthetic Auxin ◽  
Transport Behaviour ◽  
Auxin Polar Transport ◽  
2,4 Dichlorophenoxyacetic Acid

The transport behaviour of the synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D), applied in aqueous solution to the cut stem surface of sunflower seedlings decapitated in the epicotyl, was studied using steam-ringing to differentiate between apoplastic and symplastic movement. Initially the 2,4-D moved in apoplastic tissue and was distributed rapidly throughout the plant, apparently as the result of a non-auxin-specific transport process. When an amount of 2,4-D sufficient to maintain apical dominance in the decapitated seedling was applied, the initially distributed material was subsequently redistributed acropetally in the stem apoplast and accumulated in the stump apex. When a lower level of 2,4-D, insufficient to maintain apical dominance, was applied, the initially distributed material was redistributed basipetally in the stem symplast, probably via the auxin polar transport system, and accumulated in the root. It is suggested that the 2,4-D loading capacity of the polar transport system is an important factor determining both the transport behaviour of the 2,4-D and its ability to maintain apical dominance in this system.

Genome plasticity during the acquisition of embryogenic competence

Genome ◽  
1999 ◽  
Vol 42 (6) ◽  
pp. 1134-1143 ◽  
Author(s):  
Chiara Geri ◽  
Alessandra Turrini ◽  
Lucia Giorgetti ◽  
Elisa Nicoletti ◽  
Vittoria Nuti Ronchi
Keyword(s):  
Nuclear Dna ◽  
Cultured Cells ◽  
Morphological Changes ◽  
Dichlorophenoxyacetic Acid ◽  
Embryogenic Competence ◽  
Daucus Carota L ◽  
Gene Copies ◽  
Slot Blot Analysis ◽  
2,4 Dichlorophenoxyacetic Acid

Hypocotyl explants from carrot and other species experience concomitant segregation events and differentiation of homeotic structures during the first 20 days of culture on 2,4-dichlorophenoxyacetic acid (2,4-D). In addition to these cyto-morphological changes, significant amounts of nuclear DNA are lost, the molecular details of which we investigate in this paper. We have developed a slot-blot analysis assay to study the DNA content of a series of carrot samples; besides the leaves, this survey ranged over different culture timepoints: hypocotyls, cell lines, and somatic embryo stages. We carried on to study the relationship between this DNA loss and sequence complexity modulation. Results from probing sequences that correspond to different degrees of complexity, such as medium repetitive and unique sequences as well as sequences belonging to both classes (ribosomal cistrons, ubiquitin, actin, and chalcone synthase), consistently manifested a reduction in DNA levels during the acquisition of embryogenic competence. In some cases, the cultured cells would contain only 10% of the gene copies observed in the reference tissues. Modulation trends also showed that DNA levels of most sequences recover at the torpedo-plantlet stage, which again correlates DNA modulation and the acquisition of embryogenic competence. These results suggest that similar DNA variations may occur in plants in vivo during meiosis, possibly so that meiotic division may be properly completed.Key words: Daucus carota L., DNA reduction, somatic embryogenesis, totipotency, commitment.

Induction of freezing tolerance in potato (Solanum commersonii) suspension cultured cells

1992 ◽  
Vol 84 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Stephen P. Lee ◽  
Baolong Zhu ◽  
Tony H. H. Chen ◽  
Paul H. Li
Keyword(s):  
Freezing Tolerance ◽  
Cultured Cells ◽  
Solanum Commersonii ◽  
Suspension Cultured Cells

Characterisation of extracellular polysaccharides from suspension cultures of members of the Poaceae

2020 ◽  
Author(s):  
Ian Sims ◽  
K Middleton ◽  
AG Lane ◽  
AJ Cairns ◽  
A Bacic
Keyword(s):  
Cultured Cells ◽  
Oryza Sativa L ◽  
Suspension Cultures ◽  
Exchange Chromatography ◽  
Phleum Pratense ◽  
Arabinogalactan Protein ◽  
Extracellular Polysaccharides ◽  
Type Ii ◽  
Hordeum Vulgare L ◽  
Suspension Cultured Cells

Microscopic examination of suspension-cultured cells of Phleum pratense L., Panicum miliaceum L., Phalaris aquatica L. and Oryza sativa L. showed that they were comprised of numerous root primordia. Polysaccharides secreted by these suspension cultures contained glycosyl linkages consistent with the presence of high proportions of root mucilage-like polysaccharides. In contrast, suspension-cultured cells of Hordeum vulgare L. contained mostly undifferentiated cells more typical of plant cells in suspension culture. The polysaccharides secreted by H. vulgare cultures contained mostly linkages consistent with the presence of glucuronoarabinoxylan. The soluble polymers secreted by cell-suspension cultures of Phleum pratense contained 70% carbohydrate, 14% protein and 6% inorganic material. The extracellular polysaccharides were separated into four fractions by anion-exchange chromatography using a gradient of imidazole-HCl at pH 7.0. From glycosyl-linkage analyses, five polysaccharides were identified: an arabinosylated xyloglucan (comprising 20% of the total polysaccharide), a glucomannan (6%), a type-II arabinogalactan (an arabinogalactan-protein; 7%), an acidic xylan (3%), and a root-slime-like polysaccharide, which contained features of type-II arabinogalactans and glucuronomannans (65%).

Characterisation of extracellular polysaccharides from suspension cultures of members of the Poaceae

2020 ◽  
Author(s):  
Ian Sims ◽  
K Middleton ◽  
AG Lane ◽  
AJ Cairns ◽  
A Bacic
Keyword(s):  
Cultured Cells ◽  
Oryza Sativa L ◽  
Suspension Cultures ◽  
Exchange Chromatography ◽  
Phleum Pratense ◽  
Arabinogalactan Protein ◽  
Extracellular Polysaccharides ◽  
Type Ii ◽  
Hordeum Vulgare L ◽  
Suspension Cultured Cells

Microscopic examination of suspension-cultured cells of Phleum pratense L., Panicum miliaceum L., Phalaris aquatica L. and Oryza sativa L. showed that they were comprised of numerous root primordia. Polysaccharides secreted by these suspension cultures contained glycosyl linkages consistent with the presence of high proportions of root mucilage-like polysaccharides. In contrast, suspension-cultured cells of Hordeum vulgare L. contained mostly undifferentiated cells more typical of plant cells in suspension culture. The polysaccharides secreted by H. vulgare cultures contained mostly linkages consistent with the presence of glucuronoarabinoxylan. The soluble polymers secreted by cell-suspension cultures of Phleum pratense contained 70% carbohydrate, 14% protein and 6% inorganic material. The extracellular polysaccharides were separated into four fractions by anion-exchange chromatography using a gradient of imidazole-HCl at pH 7.0. From glycosyl-linkage analyses, five polysaccharides were identified: an arabinosylated xyloglucan (comprising 20% of the total polysaccharide), a glucomannan (6%), a type-II arabinogalactan (an arabinogalactan-protein; 7%), an acidic xylan (3%), and a root-slime-like polysaccharide, which contained features of type-II arabinogalactans and glucuronomannans (65%).

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