scholarly journals INTRODUCTION OF β-GLUCURONIDASE GENE INTO GINSENG (PANAX CINSENG) BY A TI-PLASMID VECTOR SYSTEM AND ITS EXPRESSION

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 621e-621
Author(s):  
Jang R. Liu ◽  
Haeng S. Lee ◽  
Suk W. Kim ◽  
Hyo W. Lee

β-Glucuronidase (GUS) gene of Escherichia coli was introduced into ginseng cells by an Agrobacterium binary vector system and expressed in somatic embryos derived from the cells. A binary vector pBI121 carrying CaMV 35S promoter-GUS gene fusion and a neomycin phosphotransferase gene as selection marker was transferred into Agrobacterium tumefaciens LBA4404. Zygotic embryo cotyledonary segments were co-cultivated with A. tumefaciens and transferred to the medium containg 1 mg 2,4-dichlorophenoxyacetic acid/liter, 0.5 mg kinetin/liter, and 100 mg kanamycin/liter. Kanamycin-resistant calli were formed after 3 to 4 weeks of culture. Southern analysis confirmed the resistant calli were transformed with GUS gene. High GUS activities were detected in somatic embryos developed from the calli.

1997 ◽  
Vol 75 (3) ◽  
pp. 509-512 ◽  
Author(s):  
P. V. Bozhkov ◽  
I. S. Ahn ◽  
Y. G. Park

Individual mature stored seeds of Pinus koraiensis sometimes contain several viable zygotic embryos originated through the processes of simple and cleavage polyembryony. To induce the embryonic process, isolated zygotic embryos were cultured on five different media all supplemented with 10 μM 2,4-dichlorophenoxyacetic acid and 5 μM 6-benzyladenine. Two alternative pathways of somatic embryo origin were revealed. The first pathway was associated with the production of a friable, translucent callus in the hypocotyls–cotyledon region of the dominant zygotic embryo. The second pathway was related to the proliferation of a translucent, moist, and mucilaginous tissue (termed embryonal–suspensor mass) in the suspensor region of the dominant zygotic embryo. Both types of tissues contained early somatic embryos. Regression analysis has shown a strong negative correlation between the frequencies of formation of embryogenic callus and embryonal–suspensor mass both at 3 and 8 weeks of culture (r = − 0.85; p = 0.07 and r = −0.71; p = 0.17, respectively). Key words: Pinus koraiensis; polyembryonal seeds; somatic embryogenesis; embryogénie callus; embryonal–suspensor mass.


2007 ◽  
Vol 59 (3) ◽  
pp. 199-202 ◽  
Author(s):  
Dragana Stojicic ◽  
Branka Uzelac ◽  
Dusica Janosevic ◽  
Ljubinka Culafic ◽  
Snezana Budimir

The potential for somatic embryogenesis in zygotic embryo and megagametophyte cultures of Pinus heldreichii was examined. Somatic embryogenesis was initiated from megagametophytes containing immature zygotic embryos at early stages of development. An induction frequency of up to 6.7% was obtained on Gresshoff and Doy medium in the presence of 2 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mg/l benzyladenine (BA). Formation and further proliferation of embryogenic tissue were achieved upon transfer of explants to a medium with reduced levels of growth regulators. Somatic embryos are being cultured for further development. .


1991 ◽  
Vol 21 (11) ◽  
pp. 1698-1701 ◽  
Author(s):  
S. A. Merkle ◽  
A. T. Wiecko ◽  
B. A. Watson-Pauley

Cultures were initiated from developing ovules and excised embryos of American chestnut (Castaneadentata (Marsh.) Borkh.), collected from five source trees on three dates during early and middle stages of fruit development. Explants were cultured initially on semisolid induction medium containing 0.25 mg/L benzyladenine and either 6 mg/L naphthaleneacetic acid or 4 mg/L 2,4-dichlorophenoxyacetic acid for 1 or 2 weeks. Then they were either transferred to hormone-free medium or medium with 0.25 mg/L benzyladenine or maintained on the original induction media. Ovules collected from three of the five trees 6 or 7 weeks postanthesis produced embryogenic cultures. Those pulsed for 1 or 2 weeks on auxin-containing medium prior to transfer to media without auxin produced multiple somatic embryos directly from the radicle end of the zygotic embryo. Cultures maintained on auxin-supplemented media initially produced proembryogenic masses, which formed globular and heart-stage embryos as they aged. Transfer of clusters of somatic embryos from auxin-supplemented media to hormone-free medium promoted maturation of embryos to the cotyledon stage.


1989 ◽  
Vol 19 (2) ◽  
pp. 285-288 ◽  
Author(s):  
S. A. Merkle ◽  
A. T. Wiecko

Tissue cultures were initiated from developing seeds of black locust (Robiniapseudoacacia L.) collected from three trees at weekly intervals from 1 week following anthesis until early fruit maturity. Explants were cultured on media containing 0, 2, or 4 mg/L 2,4-dichlorophenoxyacetic acid and 0 or 0.25 mg/L 6-benzyladenine. Seeds explanted onto hormone-supplemented media remained on these media for 1 or 3 weeks before being placed on hormone-free media, or were maintained on hormone-supplemented media for the entire study. Direct somatic embryogenesis was observed in a single culture, initiated from a seed collected 4 weeks after anthesis and cultured for 1 week on a medium supplemented with 4 mg/L 2,4-dichlorophenoxyacetic acid and 0.25 mg/L 6-benzyladenine before transfer to basal medium. Although it could not be discerned from which part of the explant somatic embryos were derived, secondary embryogenesis continued from the radicles of cotyledonary-stage somatic embryos. Most somatic embryos were well formed, with two distinct cotyledons. Embryos germinated precociously, producing plantlets that were initially weak but later gained vigor and resembled seedlings.


1999 ◽  
Vol 26 (2) ◽  
pp. 159 ◽  
Author(s):  
Francesco Damiani ◽  
Francesco Paolocci ◽  
Paul D. Cluster ◽  
Sergio Arcioni ◽  
Gregory J. Tanner ◽  
...  

Lotus corniculatus L. plants were transformed with Agrobacterium rhizogenes binary vector carrying the maize Sn regulatory gene driven by the 35S promoter. These plants showed modifications in the pattern of accumulation of proanthocyanidin (PA). All the transformed plants but one showed an increase in PA content in the root relative to control untransformed and control gus gene transformed plants (C). With respect to the PAaccumulation in leaves, Sn transgenic plants were grouped in two classes: suppressed (S), that showed a consistent reduction of foliar PAcontent, and unsuppressed (U) that did not differ significantly from controls. Dihydroflavanol reductase (DFR) and leucocyanidin reductase (LAR) enzyme activities in S and U plant leaves mirrored the changes seen with foliar PA accumulation. LAR activity in the roots was consistent with the root PA levels. Mature Sn mRNA accumulated in the leaves of U plants, but not in leaves of S plants; however, leaves of both S and U plants were able to initiate Sn transcription. All Sn-transformed plants accumulated Sn message in root tissue. A possible negative interaction of Sn and an unidentified homologous endogene is proposed for explaining the behaviour of S plants.


2013 ◽  
Vol 60 (3) ◽  
Author(s):  
Jindřich Bříza ◽  
Daniela Pavingerová ◽  
Josef Vlasák ◽  
Hana Niedermeierová

Modified versions of the Cry3A gene of Bacillus thuringiensis (Bt) were transferred into Norway spruce (Picea abies). Both the biolistic approach and Agrobacterium tumefaciens mediated procedure were employed for transformation of embryogenic tissue (ET) cultures. The latter method proved to be more efficient yielding 70 transgenic embryogenic tissue lines compared with 18 lines obtained by biolistics. The modified Cry3A genes were driven by a 35S promoter and the nptII screenable selection marker gene was used in all vectors. The transgenic ETs were molecularly characterized and converted into mature somatic embryos. Germinating embryos formed plantlets which were finally planted into perlite and their Cry3A gene transcription activities were demonstrated by RT-PCR.


2014 ◽  
Vol 6 (1) ◽  
pp. 85-91
Author(s):  
Dikash Singh THINGBAIJAM ◽  
Devi Sunitibala HUIDROM

An efficient and reproducible procedure is outlined for rapid in vitro multiplication of Zingiber officinale var. ‘Nadia’ through high frequency shoot proliferation from transverse thin cell layer (tTCL) sections of in vitro derived microrhizome. In vitro derived microrhizome of size 500 μm in thickness was used as initial explants for induction of somatic embryos. Among the different phytohormones tested, tTCL explants shows maximum calli proliferation in medium containing 2 mg/L 2,4-Dichlorophenoxyacetic acid (88.30±0.11%). Reduced concentration of 2,4 Dichlorophenoxyacetic acid was supplemented with different cytokinins for regeneration of callus. Among the different medium tested, optimum redifferentiation of somatic embryos were observed in medium containing 0.2 mg/L 2,4 Dichlorophenoxyacetic acid and 6.0 mg/L BAP (141.08±0.25). Clump of regenerated plantlets were further subculture and transfer into microrhizome inducing medium containing high sucrose concentration (8%). Plantlets with well developed microrhizome were successfully acclimatized and eventually transferred to the field. The application of studying embryo section for regeneration of plants might be useful alternative to ginger improvement programme. Histological analysis showed formation of somatic embryos and regenerated adventitious shoot.


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.


2002 ◽  
Vol 29 (8) ◽  
pp. 917 ◽  
Author(s):  
Laudete Maria Sartoretto ◽  
Luis Pedro Barrueto Cid ◽  
Ana Cristina Miranda Brasileiro

A procedure for genetic transformation of the hybrid Eucalyptus grandis × E. urophylla using particle bombardment is described. Cotyledon- and hypocotyl-derived calli growing on SP medium supplemented with 2�m�thidiazuron or on MS modified (MSM) medium supplemented with 10 m 2,4-dichlorophenoxyacetic acid (2,4-D) and 2.5�m�6-benzylaminopurine (BAP), were used as target material for bombardment assays. Multiple preincubation and bombardment conditions were tested. Tungsten particles were coated with the plasmid pBI426 harbouring a β-glucuronidase (gus) and neomycin phosphotransferase II (npt II) gene fusion controlled by a double 35S cauliflower mosaic virus (CaMV) promoter. Four days after bombardment, the transient transformation efficiency was determined by expression of the gus gene. Fully GUS-positive calli were then obtained after 105 d in MSM medium supplemented with 2,4-D, BAP, and the selective agent kanamycin at 200 mg L-1. The presence of the gus gene in these kanamycin-resistant calli was confirmed by polymerase chain reaction analysis. Extensive experiments were performed aiming to identify conditions for the regeneration of these GUS-expressing calli. However, they were unable to regenerate transgenic shoots, suggesting that conditions suitable for regeneration are unsuitable for transformation and vice versa.


1988 ◽  
Vol 66 (12) ◽  
pp. 2595-2596
Author(s):  
Susan C. MacDougall ◽  
Shona M. Ellis ◽  
Iain E. P. Taylor

A somatic polar structure was observed in white callus cultured, in the presence of 2,4-dichlorophenoxyacetic acid (10−6 M) and benzylaminopurine (4 × 10−6 M), from leaf explants taken from mature lodgepole pine trees. The structure contained elongate, vacuolate cells and small cells arranged with some resemblance to the first zygotic embryo cells. We were not able to induce further development.


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