scholarly journals Auxin-Dependent Cell Division and Cell Elongation. 1-Naphthaleneacetic Acid and 2,4-Dichlorophenoxyacetic Acid Activate Different Pathways

2005 ◽  
Vol 137 (3) ◽  
pp. 939-948 ◽  
Author(s):  
Prisca Campanoni ◽  
Peter Nick
Keyword(s):  
Cell Division ◽  
Cell Elongation ◽  
Dichlorophenoxyacetic Acid ◽  
Naphthaleneacetic Acid ◽  
Dependent Cell ◽  
2,4 Dichlorophenoxyacetic Acid

Selectivity of auxin for induction and growth of callus from excised embryo of spring and winter wheat

1984 ◽  
Vol 62 (7) ◽  
pp. 1393-1397 ◽  
Author(s):  
M. D. Zhou ◽  
T. T. Lee
Keyword(s):  
Winter Wheat ◽  
Chinese Spring ◽  
Shoot Growth ◽  
Callus Formation ◽  
Triticum Aestivum L ◽  
Dichlorophenoxyacetic Acid ◽  
Naphthaleneacetic Acid ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Methoxybenzoic Acid

The callus-promoting activity of most commonly known as well as some rarely tested auxins was compared with that of 2,4-dichlorophenoxyacetic acid (2,4-D) for in vitro culture of the excised embryo of spring and winter wheat (Triticum aestivum L.), cv. Chinese Spring and cv. Fredrick. Different auxins in a concentration range from 1 to 50 μM showed widely different activities. Also the two wheat cultivars responded differently to the auxins. When rapid callus formation with limited root growth was used as the basis for comparison, 2-(2-methyl-4-chlorophenoxy)propionic acid (2-MCPP), α-naphthaleneacetic acid, 3,6-dichloro-2-methoxybenzoic acid (dicamba), 4-amino-3,5,6,trichloropicolinic acid (picloram), γ-(2,4-dichlorophenoxy)butyric acid, 2,4,5-trichlorophenoxyacetic acid, and 2,4,5-trichlorophenoxypropionic acid, in the order of effectiveness, were superior to 2,4,-D for callus induction from the embryo of 'Chinese Spring,' although the concentration required was higher than that of 2,4-D. For the winter wheat 'Fredrick,' however, only picloram, dicamba, and 2-MCPP performed as well as 2,4-D. All auxins tested promoted shoot growth; 2-methyl-4-chlorophenoxypropionic acid was most effective for 'Chinese Spring,' whereas picloram was most effective for 'Fredrick.'

scholarly journals The mode of action of 2,4-D in counteracting the elongation of carrot cells grown in culture

1980 ◽  
Vol 45 (1) ◽  
pp. 257-268
Author(s):  
C.W. Lloyd ◽  
S.B. Lowe ◽  
G.W. Peace
Keyword(s):  
Electron Microscopy ◽  
Cell Division ◽  
Dichlorophenoxyacetic Acid ◽  
Mitogenic Effect ◽  
Suspension Cells ◽  
Carrot Cells ◽  
Cytoplasmic Microtubules ◽  
Time Periods ◽  
Per Se ◽  
2,4 Dichlorophenoxyacetic Acid

The growth regulator 2,4-D (2,4-dichlorophenoxyacetic acid) has been used to investigate the inter-relationship between cell elongation and cell division in carrot suspension cells. Maintained in 1 mg/l. 2,4-D, dividing populations of cells remain spheroidal and in clusters. But when subcultured into lower levels or zero, 2,4-D they increasingly elongate at the expense of division. Over the range of 0 to 1.0 mg/l, 2,4-D, elongation and division are therefore inversely related. However, by suppressing the mitogenic effect with FUdR it can be shown that cells do elongate in 1 mg/l. 2,4-D—a concentration which otherwise produces dividing, spheroidal cells. This indicates that mitogenc levels of 2,4-D do not perturb structures which support cellular elongation. This conclusion is confirmed by immuno- and electron-microscopy which show that development of elaborate arrays of cytoplasmic microtubules is unaffected by 1 mg/l. 2,4-D when FUdR is present. It is concluded that over the time periods under study here, 2,4-D regulates cell size (and shape) by stimulating growing cells to enter the division cycle and not by inhibiting elongation per se.

scholarly journals Auxins Regulations of Branched Spike Development and Expression of TFL, a LEAFY-Like Gene in Branched Spike Wheat (Triticum aestivum)

2017 ◽  
Vol 9 (2) ◽  
pp. 27
Author(s):  
Wang Yue ◽  
Sun Fulai ◽  
Gao Qingrong ◽  
Zhang Yanxia ◽  
Wang Nan ◽  
...  
Keyword(s):  
Photosynthetic Pigment ◽  
Dry Mass ◽  
Dichlorophenoxyacetic Acid ◽  
Naphthaleneacetic Acid ◽  
Branched Spike ◽  
Spike Development ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
The Impact ◽  
Indole 3 Acetic Acid ◽  
Putative Homologue

Branched spike wheat is a hexaploid germplasm with branched rachis on its main rachises, and the crucial period for branched rachises occurrence and development is just after the two ridges stage of shoot apex. Natural [indole-3-acetic acid (IAA), indole-3butyric acid (IBA)] and synthetic [(1-naphthaleneacetic acid (NAA), 2,4-Dichlorophenoxyacetic acid (2,4-D)] auxins were applied at this period to investigate the spike traits, seedling growth and photosynthesis related characters and expression of a putative homologue of the LEAFY in branched spike wheat. The four types of experienced auxins induced similar effects on these foresaid characters, although the impact extents were different among the auxins treatments. More branched rachis, spikelets, fertile florets and longer branched rachis were obtained in plants with IAA and IBA at 0.1 mM or NAA and 2,4-D at 1.0mM than those plants with no auxin treated. Auxin treatments also increased fresh and dry mass, photosynthetic pigment and parameters. TFL, a LEAFY-like gene was cloned in branched spike wheat and TFL mRNA expression was quantified using real-time reverse transcriptase-PCR. Application of the auxins accelerated the rise in TFL expression during the periods of branched rachises occurrence and extension. The data supports the hypothesis that auxins play a central role in the regulation branched spike development and TFL might correlate with the development of branched rachises in branched spike wheat.

An improved culture medium for growing the orchid Cypripedium reginae axenically

1982 ◽  
Vol 60 (12) ◽  
pp. 2547-2555 ◽  
Author(s):  
Gaëtan Harvais
Keyword(s):  
Acetic Acid ◽  
Membrane Filtration ◽  
Ammonium Citrate ◽  
Naphthalene Acetic Acid ◽  
Dichlorophenoxyacetic Acid ◽  
Naphthaleneacetic Acid ◽  
Growth And Survival ◽  
Murashige Skoog ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Germination And Growth

A new medium for growing Cypripedium reginae Walt. axenically from seed was designed. Liquid culture proved unsuitable, hence a 1% agar medium supplemented with 5% potato extract was used to investigate optimal mineral element, vitamin, amino acid, sugar, and growth regulator supplements for germination, and subsequent growth. A modified Pfeffer solution with 1400 mg/L NH4NO3 + 19 mg/L ammonium citrate + 2% dextrose + 10 mg/L niacin + 5 mg/L calcium pantothenate + 5 mg/L thiamine HCl + 1 mg/L kinetin + 0.1 mg/L α-naphthaleneacetic acid gave best germination and growth to 2 years with little or no phenolic production. Gamborg's B5 medium and Murashige–Skoog (MS) medium were less than optimal when tested against the above medium. Growth regulators were more active when sterilized by membrane filtration instead of autoclaving. Of the three aminopurines tested, kinetin, benzylaminopurine (BAP), and 6(γ,γ-dimethylallylamino) purine (γγ), the order of activity was initially γγ → BAP → kinetin, but kinetin produced better greening of protocorms and plantlets, and eventually greater survival. Hence, it was chosen for further study. The auxins indole-3-acetic acid (IAA), naphthalene acetic acid (NAA), indole-3-butyric acid (IBA), and 2,4-dichlorophenoxyacetic acid (2,4-D) were also tested alone and in combination with the aminopurines. They did not stimulate germination, but improved growth and survival when combined with aminopurines. The most active of the auxins were NAA → IAA → IBA → 2,4-D. A kinetin:NAA ratio of 10:1 was very satisfactory.

Citrus tissue culture: regulation of stylar abscission in excised pistils

1980 ◽  
Vol 58 (11) ◽  
pp. 1257-1261 ◽  
Author(s):  
John W. Einset ◽  
Anne Cheng ◽  
Hamid Elhag
Keyword(s):  
Tissue Culture ◽  
Cell Division ◽  
Dichlorophenoxyacetic Acid ◽  
Navel Orange ◽  
Test Medium ◽  
Fresh Weight ◽  
Valencia Orange ◽  
Washington Navel ◽  
Citrus Tissue Culture ◽  
2,4 Dichlorophenoxyacetic Acid

Lemon pistil explants were obtained by cutting just above the region of the hypogynous disc (A type explant) or at the base of the pistil (B type explant) and cultured on test medium containing Murashige and Skoog salts, 50 g sucrose/L, 100 mg myo-inositol/L, 5 mg thiamine–HCl/L, and 0.5 mg kinetin/L, plus or minus supplements. Under appropriate conditions an abscission zone formed and styles abscised after 6–8 days of culture; in the field stylar abscission occurred 12–15 days postanthesis. Abscission in A type explants was markedly inhibited by 9 μM 2,4-dichlorophenoxyacetic acid but was unaffected by indole-3-acetic, 1-naphthaleneacetic, gibberellic, abscisic, caffeic, or p-coumaric acids. The response to 2,4-dichlorophenoxyacetic acid was reduced in B type explants. In an atmosphere containing 35–200 ppm ethylene, cell division occurred in the zone of stylar abscission producing a proliferating callus, and the content of cellulase increased from 0.6 to 53.7 enzyme units/g fresh weight compared with fresh explants. Stylar abscission was inhibited by 2,4-dichlorophenoxyacetic acid in A type explants of Washington navel orange, Valencia orange, and mandarin pistils, but not of grapefruit pistils. B type explants of Washington navel orange and mandarin pistils were less responsive to 2,4-dichlorophenoxyacetic acid.

Growth substance requirements and major lipid constituents of tissue cultures of Euphorbia esula and E. cyparissias

1972 ◽  
Vol 50 (4) ◽  
pp. 723-726 ◽  
Author(s):  
T. T. Lee ◽  
A. N. Starratt
Keyword(s):  
Callus Tissue ◽  
Defined Medium ◽  
Growth Substance ◽  
Tissue Growth ◽  
Euphorbia Esula ◽  
Dichlorophenoxyacetic Acid ◽  
Naphthaleneacetic Acid ◽  
Callus Tissues ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Root Tissues

The root tissues of Euphorbia esula and E. cyparissias form callus on chemically defined medium. Both species require an exogenous supply of auxin for growth, but the appearance and color of the tissue and their responses to kinetin, 2,4-dichlorophenoxyacetic acid (2,4-D) and indoleacetic acid (IAA) are different. The tissue growth is more satisfactory with α-naphthaleneacetic acid (NAA) than with 2,4-D, IAA, or 4-amino-3,5,6-trichloropicolinic acid (picloram). Gibberellic acid has no effect. The callus tissues of E. esula become intensely green under light but are not autotrophic.Triglycerides, palmitic acid, and β-sitosterol are the major lipid constituents of the callus tissue of E. esula. Chromatographic analysis reveals no significant differences in the composition of extracts from the non-green and green tissues. Long-chain aldehydes, alcohols, and triterpenes found in the plant are not detected in the cultures.

scholarly journals Strategies for the Regeneration of Paphiopedilum callosum through Internode Tissue Cultures Using Dark–light Cycles

HortScience ◽  
2019 ◽  
Vol 54 (5) ◽  
pp. 920-925
Author(s):  
Nguyen Phuc Huy ◽  
Vu Quoc Luan ◽  
Le Kim Cuong ◽  
Nguyen Ba Nam ◽  
Hoang Thanh Tung ◽  
...  
Keyword(s):  
Stem Elongation ◽  
Gelling Agent ◽  
Dichlorophenoxyacetic Acid ◽  
Naphthaleneacetic Acid ◽  
Tissue Cultures ◽  
Organic Substances ◽  
Dark Light ◽  
Support Matrix ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Bacto Agar

Paphiopedilum spp. is one of the most commercially popular orchids because of its variety of shapes, sizes, and colors. However, it is at risk for extinction because of its exploitation. Regeneration of orchid plants using internode segments is extremely difficult. In this study, young P. callosum plants (1.5 cm) were exposed to eight dark–light cycles (14 days of dark and 1 day of light) for stem elongation to increase the number of nodes to obtain internode tissues. After 75 days of culture, the highest callogenesis (31.25%) was achieved when internode tissue was cultured on liquid Schenk and Hildebrandt (SH) medium containing 30 g·L−1 sucrose, 1.0 mg·L−1 Thidiazuron (TDZ), 1.0 mg·L−1 2,4-Dichlorophenoxyacetic acid (2,4-D), and cotton wool as the support matrix. The optimal media for induction of protocorm-like bodies (PLBs) were the same compositions as previously mentioned and were supplemented with 9 g·L−1 Bacto agar as the gelling agent. PLB clumps (5–6 PLBs/clump) produced the best shoots on medium containing 0.5 mg·L−1 α-Naphthaleneacetic acid (NAA) and 0.3 mg·L−1 TDZ. Among the organic substances tested, 200 g·L−1 potato homogenate (PH) added to Hyponex N016 medium supplemented with 1.0 mg·L−1 NAA, 30 g·L−1 sucrose, 170 mg·L−1 NaH2PO4, 1.0 g·L−1 peptone, and 9 g·L−1 Bacto agar resulted in the best rooting. The rooted plantlets with four to five leaves were acclimatized and had a 100% survival rate. The method presented in this research provides a strategy for the development of highly effective propagation of Paphiopedilum species using ex vitro explants for both conservation and horticultural purposes.

scholarly journals Long-term Effect of Winter Gibberellic Acid Sprays and Auxin Applications on Crop Value of `Clausellina' Satsuma

2006 ◽  
Vol 131 (5) ◽  
pp. 586-592 ◽  
Author(s):  
Amílcar M.M. Duarte ◽  
Amparo García-Luis ◽  
Rosa Victoria Molina ◽  
Consuelo Monerri ◽  
Vicente Navarro ◽  
...  
Keyword(s):  
Gibberellic Acid ◽  
First Grade ◽  
Dichlorophenoxyacetic Acid ◽  
Flower Formation ◽  
Naphthaleneacetic Acid ◽  
Marginal Effect ◽  
Variable Effect ◽  
Long Term Effect ◽  
2,4 Dichlorophenoxyacetic Acid

A winter gibberellic acid (GA3) spray consistently reduced flower formation, but had a variable effect on the amount of first-grade fruit in the early harvest of `Clausellina' satsuma (Citrus unshiu Marc.), and in the long term these applications had no significant effect on the value of the crop. Auxin applications increased the amount of first grade-early harvested fruit, and increased crop value as compared to hand-thinned trees. No significant differences in yield or fruit grade could be found among the different auxin applications tried, namely an application of 20 mg·L-1 2,4-dichlorophenoxyacetic acid (2,4-D) at flowering, or applications of 25 mg·L-1 naphthaleneacetic acid (NAA), or 50 mg·L-1 2,4-dicholorophenoxypropionic acid (2,4-DP) at the end of fruitlet abscission. Apart from their effect on size, the auxin applications had only a marginal effect on fruit quality.

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