A Novel Step to Transfer Transgenic Callus Primordia of Carrot , Embedded in Agar Droplets

2014 ◽  
Vol 9 (1) ◽  
pp. 44-48
Author(s):  
Amjad A. H. Mohammed ◽  
Mozahim K. Al-Mallah
Keyword(s):  
Genome ◽  
1999 ◽  
Vol 42 (6) ◽  
pp. 1234-1241 ◽  
Author(s):  
Shigeo Takumi ◽  
Koji Murai ◽  
Naoki Mori ◽  
Chiharu Nakamura

To investigate the excision of a maize transposable element in wheat cells, plasmid DNAs containing a Dissociation (Ds) element located between a rice actin 1 gene promoter and a beta-glucuronidase (GUS) gene (gus) were introduced into wheat callus lines by microprojectile bombardment, and transient GUS expression was assayed. The gus-expressing cells after Ds excision were detected only when the Activator (Ac) transposase gene was co-transformed. To further examine a relationship between the amount of Ac mRNA and the Ds excision frequency, the Ds-containing plasmids were introduced into 15 independent transgenic callus lines transformed with the Ac transposase gene. Ten lines expressed the Ac transposase gene under the control of either the cauliflower mosaic virus 35S promoter or the Ac native promoter. The gus gene expression that indicated the Ds excision was observed only in the transgenic callus lines stably expressing the Ac transposase gene. The number of blue spots reflecting the frequency of Ds excision was variable among them. Northern-blot analysis also showed a large variability in the amount of Ac transposase transcripts among the lines. It was however noted that the excision frequency was decreased at a high level of the Ac transposase transcripts, supporting the hypothesis that Ds excision is inhibited above a certain level of the Ac transposase as observed in maize and transgenic tobacco.Key words: transposon, Ds excision, Ac transposase transcript level, transgenic callus, wheat.


2011 ◽  
Vol 57 (No. 7) ◽  
pp. 277-280 ◽  
Author(s):  
D. Pavingerová ◽  
J. Bříza ◽  
H. Niedermeierová ◽  
J. Vlasák

In conifers and other plants with long reproductive cycles, transformed embryogenic tissues can serve as a convenient source of plant material for the testing of insecticidal or fungicidal transgene efficiency. In this report, transgenic embryogenic tissue was obtained after the transformation of somatic embryos of Norway spruce (Picea abies (L.) Karst.) by Agrobacterium tumefaciens with the gus-intron chimeric gene. The stable integration of transgenes was confirmed by PCR and Southern hybridization. The transformation was successful only in a suitable embryogenic cell line sensitive to Agrobacterium. Out of the nine embryogenic lines tested only one gave transgenic callus.


2013 ◽  
Vol 168 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Y.N. Shkryl ◽  
G.N. Veremeichik ◽  
V.P. Bulgakov ◽  
T.V. Avramenko ◽  
E.A. Günter ◽  
...  

Author(s):  
Jixiang Kong ◽  
Susana Martín-Ortigosa ◽  
John Finer ◽  
Nuananong Orchard ◽  
Andika Gunadi ◽  
...  

1AbstractSuccessful regeneration of genetically modified plants from cell culture is highly dependent on the species, genotype, and tissue-type being targeted for transformation. Studies in some plant species have shown that when expression is altered, some genes regulating developmental processes are capable of triggering plant regeneration in a variety of plant cells and tissue-types previously identified as being recalcitrant to regeneration. In the present research, we report that developmental genes encoding GROWTH-REGULATING FACTORS positively enhance regeneration and transformation in both monocot and dicot species. In sugar beet (Beta vulgaris ssp. vulgaris), ectopic expression of Arabidopsis GRF5 (AtGRF5) in callus cells accelerates shoot formation and dramatically increases transformation efficiency. More importantly, overexpression of AtGRF5 enables the production of stable transformants in recalcitrant sugar beet varieties. The introduction of AtGRF5 and GRF5 orthologs into canola (Brassica napus L.), soybean (Glycine max L.), and sunflower (Helianthus annuus L.) results in significant increases in genetic transformation of the explant tissue. A positive effect on proliferation of transgenic callus cells in canola was observed upon overexpression of GRF5 genes and AtGRF6 and AtGRF9. In soybean and sunflower, the overexpression of GRF5 genes seems to increase the proliferation of transformed cells, promoting transgenic shoot formation. In addition, the transformation of two putative AtGRF5 orthologs in maize (Zea mays L.) significantly boosts transformation efficiency and resulted in fully fertile transgenic plants. Overall, the results suggest that overexpression of GRF genes render cells and tissues more competent to regeneration across a wide variety of crop species and regeneration processes. This sets GRFs apart from other developmental regulators and, therefore, they can potentially be applied to improve transformation of monocot and dicot plant species.


1994 ◽  
Vol 119 (2) ◽  
pp. 367-373 ◽  
Author(s):  
Xiaojian Ye ◽  
Susan K. Brown ◽  
Ralph Scorza ◽  
John Cordts ◽  
John C. Sanford

Physical and biological parameters affecting the efficiency of biolistic transformation of peach were optimized using ß-glucuronidase (GUS) as a reporter gene, such that efficiency of transient GUS expression in peach embryo-derived callus was increased markedly. Transient expression was also obtained in embryonic axes, immature embryos, cotyledons, shoot tips, and leaves of peach. Stable expression of a fusion gene combining neomycin phosphotransferase (NPTII) and ß-glucuronidase activities has been achieved in peach embryo calli. Sixty-five kanamycin-resistant callus lines were obtained from 114 pieces of bombarded calli after 4 months of selection. Nineteen of the 65 putative transformant lines produced shoot-like structures. Seven lines were examined to confirm stable transformation using the colorimetric GUS assay and PCR analysis. All seven lines showed GUS activity. PCR analysis confirmed that, in most of the putative transformants, the chimeric GUS/NPTII gene had been incorporated into the peach genome. The transgenic callus lines were very weakly morphogenic, presumably because the callus was 5 years old and no transgenic shoots developed from this callus. Results of this research demonstrate the feasibility of obtaining stable transgenic peach tissue by biolistic transformation.


2011 ◽  
Vol 6 (11) ◽  
pp. 1934578X1100601 ◽  
Author(s):  
Paola Pecchia ◽  
Maria Cammareri ◽  
Nicola Malafronte ◽  
M. Federica Consiglio ◽  
Maria Josefina Gualtieri ◽  
...  

Several different classes of secondary metabolites, including flavonoids, triterpenoid saponins and quinic acid derivatives, are found in Aster spp. (Fam. Asteraceae). Several Aster compounds revealed biological as well as pharmacological activities. In this work, a phytochemical investigation of A. caucasicus evidenced the presence of quinic acid derivatives, as well as the absence of triterpene saponins. To combine in one species the production of different phytochemicals, including triterpenes, an Agrobacterium-mediated transformation of A. caucasicus was set up to introduce A. sedifolius β-amyrin synthase (AsOXA1)-encoding gene under the control of the constitutive promoter CaMV35S. The quali-quantitative analysis of transgenic calli with ectopic expression of AsOXA1 showed, in one sample, a negligible amount of triterpene saponins combined with higher amount of quinic acid derivatives as compared with the wild type callus.


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