Interaction of cytokinin, auxin, and gibberellin on peroxidase isoenzymes in tobacco tissues cultured in vitro

1972 ◽  
Vol 50 (12) ◽  
pp. 2471-2477 ◽  
Author(s):  
T. T. Lee
Keyword(s):  
Indoleacetic Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Dichlorophenoxyacetic Acid ◽  
Tobacco Callus ◽  
Tumor Type ◽  
Low Concentrations ◽  
Most Significant Change ◽  
High Concentrations ◽  
2,4 Dichlorophenoxyacetic Acid

Peroxidase in tobacco callus tissue (Nicotiana tabacum, cv. White Gold) was resolved into three groups of isoenzymes by polyacrylamide gel electrophoresis, and a combined action of cytokinin, auxin, and gibberellin in their formation was clearly demonstrated. The most significant change was in a group of fast-migrating isoperoxidases, the development of which required both kinetin and indoleacetic acid. Kinetin was most stimulatory at 0.2 μM but became inhibitory with increasing concentrations. Indole acetic acid was effective at concentrations from 0.1 to 100 μM with an optimum at 10 μM. With both kinetin and indoleacetic acid at optimal concentrations, addition of gibberellic acid further increased the contents of the fast migrating isoperoxidases, but it was inactive in the absence of indoleacetic acid or in the presence of kinetin in 5 μM or higher concentrations. Cycloheximide, actinomycin D, and abscisic acid inhibited the formation of the fast-migrating peroxidases. Formation of the fast-migrating isoperoxidase in the tissue was associated with tumor-type growth.2,4-Dichlorophenoxyacetic acid had a dual effect on peroxidase; at low concentrations (0.1 to 1 μM) it promoted a fast-migrating isoperoxidase; at high concentrations (10 to 100 μM) it inhibited the fast-migrating isoperoxidase but caused a significant increase in other isoperoxidases of lower electrophoretic mobilities.

scholarly journals Effects of 2,4-D on the germination of megaspores and initial development of Regnellidium diphyllum Lindman (Monilophyta, Marsileaceae)

2010 ◽  
Vol 70 (2) ◽  
pp. 361-366 ◽  
Author(s):  
MBB Cassanego ◽  
A Droste ◽  
PG Windisch
Keyword(s):  
Primary Root ◽  
The State ◽  
Dichlorophenoxyacetic Acid ◽  
Agricultural Activities ◽  
Rio Grande Do Sul ◽  
Initial Development ◽  
Low Concentrations ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Sporophytic Development

Regnellidium diphyllum is considered as endangered, occurring in the State of Rio Grande do Sul, Brazil, and a few adjoining localities in Uruguay, Argentina and the State of Santa Catarina. It grows in wetlands frequently altered for agricultural activities. Herbicides based on 2,4-dichlorophenoxyacetic acid (2,4-D) are widely used in these fields. The effects of 2,4-D on the germination of megaspores and initial sporophytic development of R. diphyllum were investigated. Six concentrations of 2,4-D (0.32; 0.64; 1.92; 4.80; 9.60 and 19.20 mg.L-1), and the control (0.00 mg.L-1), were tested in vitro, using Meyer's medium. Cultures were maintained in a growth chamber at 24 ± 1 °C, under artificial light with nominal irradiance of 110 µmol.m-2/s and 16 hours photoperiod. Megaspore germination was lower at 9.60 and 19.20 mg.L-1 of 2,4-D (56 and 48%, respectively), compared with the control (68%). Herbicide concentrations of up to 1.92 mg.L-1 did not significantly decrease the number of sporophytes formed. At 19.20 mg.L-1, no sporophytes were formed. The lengths of the primary root, primary and secondary leaves were greater at concentrations of 0.32 and 0.64 mg.L-1 of 2,4-D. Low concentrations of 2,4-D do not affect germination rates and initial development of R. diphyllum in a significant way. However, higher concentrations (9.60 and 19.20 mg.L-1) affect substantially the germination of the megaspores and interfere with the establishment of the species.

scholarly journals Smooth leaf (spineless) Red Spanish pineapple (Ananas comosus) propagated in vitro

1969 ◽  
Vol 73 (4) ◽  
pp. 301-311
Author(s):  
Lii J. Liu ◽  
Evelyn Rosa-Márquez ◽  
Enid Lizardi
Keyword(s):  
Callus Formation ◽  
Ananas Comosus ◽  
Dichlorophenoxyacetic Acid ◽  
Meristem Culture ◽  
Standard Medium ◽  
Shoot Differentiation ◽  
Low Concentrations ◽  
One Year ◽  
2,4 Dichlorophenoxyacetic Acid

Some 40,000 plantlets of Red Spanish pineapple [Ananas comosus (L. Merr.)] were produced via meristem culture. Of these, approximately 50% were spineless. Some of these spineless plantlets reversed to spiny leaf. However, the percentage of reversion from spineless to spiny was 14.1% and that from spiny to spineless was 32.7%. Of the 2,318 plantlets examined in the laboratory and greenhouse during a 3- to 4-month period, 72.9% of the spiny Red Spanish pineapple remained spiny and 85.8% of the spineless remained spineless. One year after field planting, the spineless Red Spanish remained largely spineless and initiated flowering and fruit settings the same as the spiny ones. The standard medium for in vitro propagation of Red Spanish pineapple was improved by supplementing Murashige and Skoog's basic formula (MS) with 0.1 mg/L, 2,4- dichlorophenoxyacetic acid (2,4-D) + 0.5 mg/L benzyl adenine (BA). The callus formation was improved by adding to the same MS formula 10 mg/L BA + 4 mg/L naphtalene acetic acid (NAA). Similarly, shoot differentiation was improved by adding low concentrations of hormone (0.1 mg/L NAA) to the Abo El-Nil and Zettler (AZ) medium.

INDUCTION AND MAINTENANCE OF EMBRYOGENIC CHARACTERISTICS OF CALLUS OF THE OIL PALM HYBRID MANICORÉ

2021 ◽  
Vol 45 ◽  
Author(s):  
Marlúcia Souza Pádua Vilela ◽  
Jéssica de Castro e Andrade ◽  
Raíssa Silveira Santos ◽  
Vanessa Cristina Stein ◽  
Patrick Callegari Magnani Santos Alves ◽  
...  
Keyword(s):  
Oil Palm ◽  
Large Scale ◽  
Elaeis Guineensis ◽  
Callus Formation ◽  
Leaf Explants ◽  
Dichlorophenoxyacetic Acid ◽  
In Vitro Cultivation ◽  
Low Concentrations ◽  
2,4 Dichlorophenoxyacetic Acid

ABSTRACT Large-scale oil palm propagation (Elaeis guineensis Jacq.) is difficult due to its unique apical meristem. In this context, micropropagation allows the multiplication of seedlings in vitro and the storage of germplasm elites. This study aimed to induce embryogenic calluses from leaves of oil palm plants in low concentrations of auxins and to observe the maintenance of these characteristics during in vitro cultivation. Calluses were induced in 0.5 cm leaf explants in Y3 culture medium supplemented with Picloram (4-Amino-3,5,6-trichloro-2-pyridinecarboxylic acid) or 2,4-D (2,4-dichlorophenoxyacetic acid), at concentrations of 0, 1, 3, 6, and 9 mg L-1. The callus with embryogenic appearance was subcultured and evaluated regarding maintenance of embryogenic characteristics by cytochemical analyses. The best treatment for induction of calluses was composed of 1mg.L-1 of Picloram, which led to 30% callus formation. The calluses were classified into4 types, based on color and morphology. The cells of calluses with nodular and beige appearance have embryogenic characteristics, and the embryogenic potential of the cell masses was maintained over the 20 months of cultivation. This differentiated adaptation to the protocol can allow the advance in the mass propagation of oil palm through tissue culture, indicating the importance of investigating the topics proposed by the research.

scholarly journals Micropropagation and callogenesis in Mandevilla guanabarica (Apocynaceae), an endemic plant from Brazil

2014 ◽  
Vol 14 (2) ◽  
pp. 108-115 ◽  
Author(s):  
Sandra Zorat Cordeiro ◽  
Naomi Kato Simas ◽  
Anaize Borges Henriques ◽  
Alice Sato
Keyword(s):  
Culture Medium ◽  
Woody Plant ◽  
Boron Concentration ◽  
Dichlorophenoxyacetic Acid ◽  
Endemic Plant ◽  
Plant Maintenance ◽  
Different Types ◽  
High Concentrations ◽  
2,4 Dichlorophenoxyacetic Acid

Mandevilla guanabarica is an endemic plant from Brazil, with pharmacological and ornamental potential, both unexplored. This study established the best culture medium for in vitro plant maintenance, efficient protocol for its regeneration, and callogenesis from different explants excised from in vitro-grown plants. Woody plant medium with double boron concentration (WPM B) plus 2.27 µM thidiazuron or 0.49 µM 2-isopentenyladenine provided multiplication rates higher than 1:6. Shoots were 100% rooted on WPM B. After acclimatization, plants showed 83% survival. For callogenesis, the use of MS media supplemented with high concentrations of picloram or 2,4-dichlorophenoxyacetic acid produced, respectively, friable or compact non-morphogenic calluses from different types of explants. This micropropagation protocol allows the production of seedlings of M. guanabarica for ornamental or commercial uses, and for conservation purposes; calluses can be used to establish suspension cultures in prospecting for bioactive compounds.

An Ultrastructure Study of Tumor Cells of Haworthia Plants Induced by 2,4-D

1975 ◽  
Vol 33 ◽  
pp. 560-561
Author(s):  
J. S. Sullender ◽  
S. K. Majumdar
Keyword(s):  
Tumor Cells ◽  
Uranyl Acetate ◽  
Dichlorophenoxyacetic Acid ◽  
Tumor Type ◽  
Induced Tumors ◽  
Acetate Lead ◽  
The Media ◽  
High Concentrations ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
And Control

Treatment of normal callus cells of Haworthia variegata with high concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) promoted the development of tumor-type growth. At low concentrations (1 and 2 mg/liter), 2,4-D had little adverse effects on the growth and morphogenesis of the callus, however, in some tubes abnormal-appearing roots were detected. Calli on the media containing 5, 10 and 20 mg/liter of 2,4-D developed pink-brown pigmentation, produced numerous minute nodules, induced tumor-type growth, showed little differentiation and produced abnormal roots and leaves. Ultrastructure studies of auxin-induced tumors in some plants have been made by several investigators, however, no information is available on the fine structure of the 2,4-D induced tumor cells of Haworthia plants. Tissues from tumor and control groups were fixed in 2% osmium tetroxide, post-fixed in 4% glutaraldehyde, and embedded in Epon 812. Sections were cut on a Porter-Blum MT-2 ultramicrotome, stained with uranyl acetate-lead citrate and examined on a Philips Model 201 transmission electron microscope operating at 60 kV.

The morphology and anatomy of holdfasts and branching radicles of Arceuthobium pusillum cultured in vitro

1969 ◽  
Vol 47 (12) ◽  
pp. 1935-1938 ◽  
Author(s):  
J. M. Bonga
Keyword(s):  
Indoleacetic Acid ◽  
Casein Hydrolysate ◽  
Dichlorophenoxyacetic Acid ◽  
Dwarf Mistletoe ◽  
Flat Structures ◽  
Meristematic Activity ◽  
Milk Casein ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Center Area

Seeds of the eastern dwarf mistletoe, Arceuthobium pusillum Peck, were cultured on White's medium supplemented with coconut milk, casein hydrolysate, and indoleacetic acid (IAA) or 2,4-dichlorophenoxyacetic acid (2,4-D). Large holdfasts were obtained with 2,4-D. At first, growth of these holdfasts arose from a centrally located meristem, but later from growth centers near the periphery of the holdfasts. Reticulate thickening of the cell walls was observed in the center area of the holdfasts. With IAA, flat structures with branches or papillae were obtained. If the seeds were cultured with 2,4-D for 3 months and then with IAA, a number of holdfasts formed branches. Centers of meristematic activity developed occasionally where radicles and branches were subjected to pressure.

In vitro culture of Bouvardia ternifolia

1982 ◽  
Vol 60 (6) ◽  
pp. 917-921 ◽  
Author(s):  
Leonor Fernandez ◽  
Estela Sanchez de Jimenez
Keyword(s):  
Indoleacetic Acid ◽  
Cell Suspension Cultures ◽  
Callus Cultures ◽  
Suspension Cultures ◽  
Dichlorophenoxyacetic Acid ◽  
Naphthaleneacetic Acid ◽  
Napthaleneacetic Acid ◽  
Leaf Tissues ◽  
2,4 Dichlorophenoxyacetic Acid

Callus cultures were induced from radicle and leaf tissues of Bouvardia ternifolia (trompetilla). Optimum growth regulator concentrations for radicle callus cultures were 1 mg/L 2,4-dichlorophenoxyacetic acid and 0.005 mg/L kinetin; for leaf callus they were either 2 mg/L naphthaleneacetic acid and 0.002 mg/L benzylaminopurine or 5 mg/L of idoleacetic acid and 0.01 mg/L kinetin. Callus has been maintained in culture for nearly 3 years with a very rapid growth rate.A generation time of approximately 24 to 28 h was obtained for batch cell suspension cultures. Production of protoplasts from suspension cultures was optimized with a yield of 70 to 90%. Protoplast culture was achieved in droplets of fresh medium with 2 mg/L napthaleneacetic acid, 0.01 mg/L benzylaminopurine, and0.5 M mannitol. After 2 years, callus in culture still retained its organogenetic capacity. An average of 18 complete plantlets from approximately 2 g of callus can be obtained after transfer to medium with 0.1 mg/L indoleacetic acid and 0.1 mg/L benzylaminopurine.

scholarly journals In vitro induction of callus from cotyledon and hypocotyl explants of Glycine wightii (Wight & Arn.) Verdc.

2003 ◽  
Vol 27 (6) ◽  
pp. 1277-1284 ◽  
Author(s):  
André Luis Coelho da Silva ◽  
Cecília Sulzbacher Caruso ◽  
Renato de Azevedo Moreira ◽  
Ana Cecília Góes Horta
Keyword(s):  
Callus Induction ◽  
Basal Medium ◽  
Average Weight ◽  
Dichlorophenoxyacetic Acid ◽  
Fresh Matter ◽  
Growth Room ◽  
High Concentrations ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
In Vitro Induction

With the objective to promote in vitro callus induction, cotyledon and hypocotyl segments of "perennial soybean" (Glycine wightii (Wight & Arn.) Verdc.) were inoculated in basal medium MS supplemented with sucrose (1.5 e 3%) and 0.8% agar and different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-furfurylaminopurine (kinetin). The explants were maintained in a dark growth room at 28ºC. The best callus induction was observed in explants (cotyledon and hypocotyl) maintained in medium containing the combination of 2,4-D (1 mg.L-1), kinetin (0.1 mg.L-1) and 3% sucrose. To promote callus subculture, the MS medium was supplemented with different combinations of 2,4-D (0.5 to 4.0 mg.L-1), with or without kinetin (0.1 mg.L-1) and sucrose (1.5 e 3%). The calli were maintained 35 days in a dark growth room at 28ºC. The results indicated that the use of 2,4-D 1.0 mg.L-1 + kinetin 0.1 mg.L-1 + sucrose 3% provided the highest average weight of cotyledons calli fresh matter, whereas the use of 2,4-D 2.0 mg.L-1 + kinetin 0.1 mg.L-1 + sucrose 3% provided the highest average weight of hypocotyl calli fresh matter. High concentrations of 2,4-D, independent of kinetin and sucrose concentrations, promoted oxidation and reduction in fresh weight from calli of cotyledon and hypocotyls.

In Vitro Effects of Ethanol on Rabbit Platelet Aggregation, Secretion of Granule Contents, and Cyclic AMP Levels in the Presence of Prostacyclin

1989 ◽  
Vol 61 (02) ◽  
pp. 254-258 ◽  
Author(s):  
Margaret L Rand ◽  
Peter L Gross ◽  
Donna M Jakowec ◽  
Marian A Packham ◽  
J Fraser Mustard
Keyword(s):  
Cyclic Amp ◽  
Inhibitory Effect ◽  
Rabbit Platelet ◽  
Inhibitory Effects ◽  
Low Concentrations ◽  
Rabbit Platelets ◽  
High Concentrations ◽  
In Vitro Effects ◽  
Aggregation Of Platelets

SummaryEthanol, at physiologically tolerable concentrations, inhibits platelet responses to low concentrations of collagen or thrombin, but does not inhibit responses of washed rabbit platelets stimulated with high concentrations of ADP, collagen, or thrombin. However, when platelet responses to high concentrations of collagen or thrombin had been partially inhibited by prostacyclin (PGI2), ethanol had additional inhibitory effects on aggregation and secretion. These effects were also observed with aspirin- treated platelets stimulated with thrombin. Ethanol had no further inhibitory effect on aggregation of platelets stimulated with ADP, or the combination of ADP and epinephrine. Thus, the inhibitory effects of ethanol on platelet responses in the presence of PGI2 were very similar to its inhibitory effects in the absence of PGI2, when platelets were stimulated with lower concentrations of collagen or thrombin. Ethanol did not appear to exert its inhibitory effects by increasing cyclic AMP above basal levels and the additional inhibitory effects of ethanol in the presence of PGI2 did not appear to be brought about by further increases in platelet cyclic AMP levels.

Aggregation of Cat Platelets in Vitro

1970 ◽  
Vol 23 (03) ◽  
pp. 601-620 ◽  
Author(s):  
Th. B Tschopp
Keyword(s):  
Adenosine Monophosphate ◽  
Blood Collection ◽  
Base Line ◽  
Reversible Aggregation ◽  
Low Concentrations ◽  
Irreversible Aggregation ◽  
High Concentrations ◽  
Two Phases ◽  
Improved Technique

SummaryAggregation of cat platelets in the citrated plasma is examined by means of Born’s absorptiometer. A marked tendency of the platelets of this species to spontaneous aggregation necessitated first of all the development of an improved technique of blood collection.A hypothesis according to which 5-HT is released from the platelets, explains the absence of oscillations on the base line of the absorptiometer, the absence of platelet swelling, when ADP is added, and the effect of stirring on the aggregation curves in cat PRP. The average volume of cat platelets amounts to 10.46 μ3 when directly fixed in the blood, when fixed from PRP to 12.17 μ3, when fixed from stirred PRP to 13.51 μ3.In low concentrations (0.3-2 μM) ADP produce reversible aggregation; in narrowly restricted, individually dissimilar mean concentrations irreversible aggregation in two phases and in high concentrations, irreversible aggregation in one phase. Like ADP serotonin produces 2 phase irreversible aggregation in concentrations of 3-10 μM, but unlike ADP, the aggregation velocity decreases again with high 5-HT concentrations (>100 μM). Adrenaline does not produce aggregation and it is likely that adenosine and adenosine monophosphate inhibit the aggregation by serotonin but not by ADP. Species differences in the aggregation of human, rabbit and cat platelets are discussed.

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