The isolation and cultivation of protoplasts from cell suspensions of a pantothenate-requiring auxotroph of Datura

1985 ◽  
Vol 63 (4) ◽  
pp. 779-783 ◽  
Author(s):  
M. Mii ◽  
S. Seeni ◽  
L. C. Fowke ◽  
J. King

Protoplasts isolated from Datura cells requiring pantothenate for growth (Pn1 cell line) failed to divide in a medium containing 0.5 M mannitol if the cells from which they were derived had been subcultured in liquid medium more than four times. Division could be reinduced either by increasing the concentration of 2,4-dichlorophenoxyacetic acid (2,4-D) in the growth medium from 1 to 2.5–5 mg/L, by adding low concentrations (0.01 – 1 mg/L) of benzyladenine to a growth medium containing 1 mg/L of 2,4-D, or by diluting the 0.5 M mannitol in the medium to 0.2 M immediately after isolation of the protoplasts. Thus, the physiological state of Pn1 cells seems to change significantly after only a few passages in liquid medium. These changes can be prevented or partially reversed by manipulating the medium in which the cells and protoplasts are cultured. Similar physiological changes did not occur in the case of cultured wild-type (Ph4), adenine-requiring (Ad1), or isoleucine–valine-requiring (I–VI) cells of Datura.

1984 ◽  
Vol 62 (6) ◽  
pp. 1245-1249 ◽  
Author(s):  
L. S. Kott ◽  
K. J. Kasha

Somatic embryogenesis was induced in callus previously initiated from immature embryos of barley. These cultures ranged in age from 6 weeks to 30 months. Embryoids were readily initiated from homogenized suspension-grown aggregates when plated on modified B5 media with 2,4-dichlorophenoxyacetic acid. Low concentrations (0.1 and 0.05 mg∙L−1) of abscisic acid promoted further maturation of embryoids, while gibberellic acid (1 mg∙L−1) and kinetin (0.1 mg∙L−1) were used in the media to encourage embryoid germination. The development of somatic embryoids from initiation through maturation and germination is described.


2010 ◽  
Vol 70 (2) ◽  
pp. 361-366 ◽  
Author(s):  
MBB Cassanego ◽  
A Droste ◽  
PG Windisch

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.


1969 ◽  
Vol 73 (4) ◽  
pp. 301-311
Author(s):  
Lii J. Liu ◽  
Evelyn Rosa-Márquez ◽  
Enid Lizardi

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.


2015 ◽  
Vol 10 (5) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Aya Inoue ◽  
Shinjiro Ogita ◽  
Shinpei Tsuchiya ◽  
Reiko Minagawa ◽  
Hamako Sasamoto

Callus induction, maintenance and protoplast cultures were achieved from immature seeds of a woody leguminous mangrove, Caesalpinia crista. Axenic cultures were possible during 1.5 months of pod storage in 0.1% benzalkonium chloride solution. Callus induction was achieved using 1 mL liquid medium in a 10 mL flat-bottomed culture tube. Protoplasts were isolated using Cellulase R10, Hemicellulase, and Driselase 20 in 0.6 M mannitol solution and sub-culturable calluses were obtained in 50 μL liquid medium using a 96-microplate method. The optimal hormonal concentration was 10 μM each of 2,4-dichlorophenoxyacetic acid and benzyladenine in liquid Murashige and Skoog's basal medium for both callus induction and maintenance, and protoplast cultures. Similarities and differences in amino acid profiles and culture conditions are discussed among woody mangrove species and non-mangrove leguminous species. Caesalpinia crista cultures were unique as they secreted a large amount of amino acids, including proline, into the liquid culture medium.


2002 ◽  
Vol 29 (5) ◽  
pp. 575 ◽  
Author(s):  
Nello Ceccarelli ◽  
Alessandra Mondin ◽  
Roberto Lorenzi ◽  
Piero Picciarelli ◽  
Fiorella Lo Schiavo

In the present work, the characterization of two variant cell lines of carrot capable of growing in high (92 μmol L–1) concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) is reported. Both these cell lines (4w77 and 4w13) show a significantly lower uptake of 2,4-D with respect to wild-type (wt) cells. In contrast to wt cells, influx of IAA is not reduced by the addition of 100 μM 2,4-D and the presence of this compound appears to stimulate IAA uptake. When grown in the presence of high concentrations of 2,4-D, both 4w77 and 4w13 cells show behavioural differences: instead of lowering the endogenous level of free IAA, the two resistant lines react to the high exogenous concentrations of auxin by raising the level of the free hormone. In 4w77 cells, this is accomplished by reduction of auxin released in the external medium or converted to amide-linked conjugates. In 4w13 cells, the final level of endogenous IAA is an equilibrium between increased synthesis of IAA and a massive release into the medium of the ester- and free-forms of IAA. Both cell lines show disturbances in embryogenesis: line 4w77 forms globular embryos that only mature into aberrant forms having multiple axes, whereas line 4w13 has completely lost its morphogenic capacity.


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 ◽  
...  

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.


1995 ◽  
Vol 43 (4) ◽  
pp. 385-390 ◽  
Author(s):  
S. Kulothungan ◽  
A. Ganapathi ◽  
A. Shajahan ◽  
K. Kathiravan

Embryogenic callus was induced from seedling leaf explants of cowpea (Vigna unguiculata (L.) Walp. cv. C152 on Murashige and Skoog (MS) medium containing 2.0 mg 1−1 2,4-dichlorophenoxyacetic acid (2,4-D). The maximum frequency of somatic embryogenesis was noticed when this callus was transferred to MS liquid medium supplemented with 2 mg 1−1 2,4-D. Further studies on ontogeny of somatic embryos showed that the cells destined to become somatic embryos divided into spherical or filamentous proembryos. Subsequent divisions in the proembryo led to globular, heart, torpedo-shaped, and cotyledonary-stage somatic embryos. Tiny plantlets were obtained by transferring the cotyledonary-stage somatic embryos to MS liquid medium containing 0.5 mg 1−1 2,4-D.


2021 ◽  
Vol 22 (7) ◽  
pp. 3355
Author(s):  
Anna Ciarkowska ◽  
Maciej Ostrowski ◽  
Anna Kozakiewicz

Here, we report a biochemical characterization of recombinant maize indole-3-acetyl-β-d-glucose (IAGlc) synthase which glucosylates indole-3-acetic acid (IAA) and thus abolishes its auxinic activity affecting plant hormonal homeostasis. Substrate specificity analysis revealed that IAA is a preferred substrate of IAGlc synthase; however, the enzyme can also glucosylate indole-3-butyric acid and indole-3-propionic acid with the relative activity of 66% and 49.7%, respectively. KM values determined for IAA and UDP glucose are 0.8 and 0.7 mM, respectively. 2,4-Dichlorophenoxyacetic acid is a competitive inhibitor of the synthase and causes a 1.5-fold decrease in the enzyme affinity towards IAA, with the Ki value determined as 117 μM, while IAA–Asp acts as an activator of the synthase. Two sugar-phosphate compounds, ATP and glucose-1-phosphate, have a unique effect on the enzyme by acting as activators at low concentrations and showing inhibitory effect at higher concentrations (above 0.6 and 4 mM for ATP and glucose-1-phosphate, respectively). Results of molecular docking revealed that both compounds can bind to the PSPG (plant secondary product glycosyltransferase) motif of IAGlc synthase; however, there are also different potential binding sites present in the enzyme. We postulate that IAGlc synthase may contain more than one binding site for ATP and glucose-1-phosphate as reflected in its activity modulation.


1991 ◽  
Vol 69 (7) ◽  
pp. 1583-1592
Author(s):  
C. Watin-de-Pontfarcy ◽  
C. Bigot

Protoplasts were isolated from cell suspensions of Apium graveolens L. variety rapaceum (celeriac) initiated and subcultured on Gamborg medium (B5) with 2,4-dichlorophenoxyacetic acid (2.26 μM) and 6-benzylaminopurine (1.1 μM). The microcalli fraction above 450 μm was taken from 6-days-old cell suspensions and put into an enzyme mixture of cellulase Onozuka R-10 (2%) and pectolyase Y-23 (0.1%). Protoplasts were cultured on Lazar et al. modified medium with 2,4-dichlorophenoxyacetic acid (2.26 μM), naphthaleneacetic acid (0.89 μM), and zeatin (0.5 μM) at a density of 3 × 105∙mL−1. They were kept in darkness at alternating temperatures: 28 and 22 °C during 16 and 8 h, respectively. The culture medium was partially renewed after 7, 14, and 21 days of culture. Cell division rate represented about 30–40% of viable protoplasts. Addition of 2,4-dichlorophenoxyacetic acid (2.26 μM) in the microcalli plating medium improved embryogenic differentiation and subsequent plantlet isolation. Calli from protoplasts showed a variable capacity for somatic embryogenesis on Murashige and Skoog medium containing kinetin (1.4 μM). Plantlet growth was observed more particularly on microcalli plating medium without growth regulators. After acclimatization, a great number of plants with abnormal morphology was noted from calli cultivated on medium with kinetin. No variation of the normal ploidy level (2n = 2x = 22) has been recorded among the examined plants. Key words: Apium graveolens, protoplast, somatic embryogenesis, somaclonal variation, flowering.


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