Biolistic transformation of Eucalyptus grandis x E. urophylla callus

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.

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.


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 527c-527 ◽  
Author(s):  
Joyce Van Eck ◽  
Franzine Smith ◽  
Ala D. Blowers ◽  
John Sanford

Particle bombardment was investigated as a potential transformation method for Easter lily. Bulb scale explants from Lilium longiflorum Thunb. `Nellie White' were used as target material. The uidA (or gusA) reporter gene for ß- glucuronidase (GUS) expression was used in all particle bombardments to assess efficiency of gene delivery. Parameters examined to achieve optimal levels of transient GUS expression included gene promoter, helium pressure (particle velocity), and target distance. The highest level of transient GUS expression (as measured by number of indigo-stained cells/scale explant) was observed with the rice actin 1 (Act1) promoter, a helium pressure of 1500 psi, and target distances of 9 to 12 cm. Parameters considered for recovery of stable transform ants included the choice of selective agent (phosphinothricin or hygromycin) and their respective selectable resistance genes (phosphinothricin acetyltransferase and hygromycin phosphotransferase), and preculture time of scale explants prior to bombardment. Polymerase chain reaction analysis will be used to screen putative stable transformants, and from this data it will be determined which parameters yielded the highest transformation rates.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 460e-460 ◽  
Author(s):  
Marisa F. de Oliveira ◽  
Gerson R. de L. Fortes ◽  
João B. da Silva

The aim of this work was to evaluate the organogenesis of Marubakaido apple rootstock under different aluminium concentratons. The explants were calli derived from apple internodes treated with either 2,4-dichlorophenoxyacetic acid or pichloram at 0.5 and 1.0 μM and under five different aluminium concentrations (0, 5, 10, 15, 20 mg/L). These calli were then treated with aluminium at 0, 5, 10, 15, and 20 mg/L. It was observed shoot regeneration only for those calli previously treated with pichloram. There were no significant difference among the aluminium concentrations.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 483a-483
Author(s):  
Roy N. Keys ◽  
Dennis T. Ray ◽  
David A. Dierig

Guayule (Parthenium argentatum Gray, Asteraceae) is a latex-producing perennial desert shrub that is potentially of economic importance as an industrial crop for the desert Southwest. It is known to possess complex reproductive modes. Diploids are predominantly sexual and self-incompatible, while polyploids show a range of apomictic potential and self-compatibility. This paper describes the development of a relatively rapid and simple technique for characterizing reproductive modes of breeding lines of P. argentatum. Initial field experiments were based on an auxin test used successfully to characterize reproductive mode in the Poaceae. The application of 2,4-dichlorophenoxyacetic acid inhibited embryo formation in P. argentatum, but this was not the case with other auxins tested. Results of field experiments were ambiguous because: 1) the floral structure of P. argentatum is such that auxins might not have penetrated to the ovules, and 2) there was potential self-fertilization by pollen released within isolation bags. Therefore, in vitro culture of flower heads was tested because it provided much better control of environmental conditions, growth regulator application, and pollen release. Auxin alone, or in combination with gibberellic acid or kinetin, inhibited parthenogenesis in vitro. Embryo production did not vary using two substantially different nutrient media. In vitro flower head culture using a (Nitsch and Nitsch) liquid nutrient medium without growth regulators, enabled characterization of the reproductive mode of seven breeding lines, ranging from predominantly sexual to predominantly apomictic. The results of this technique were substantiated using RAPD analyzes of progeny arrays from controlled crosses.


1997 ◽  
Vol 36 (10) ◽  
pp. 27-36 ◽  
Author(s):  
P. Mungkarndee ◽  
S. M. Rao Bhamidimarri ◽  
A. J. Mawson ◽  
R. Chong

Biodegradation of the mixed inhibitory substrates, 2,4-dichlorophenoxyacetic acid (2,4-D) and para-chloro-ortho-cresol (PCOC) was studied in aerobic batch cultures. Each substrate added beyond certain concentrations inhibited the degradation of the other. This mutual inhibition was found to be enhanced by 2,4-dichlorophenol (2,4-DCP) which is an intermediate metabolic product of 2,4-D. When 2,4-DCP accumulated to approximatelY 40 mg/l degradation of all compounds in the mixed 2,4-D and PCOC substrate system was completely inhibited. The degradation of 2,4-D and PCOC individually was also found to be inhibited by elevated concentrations of 2,4-DCP added externally, while PCOC inhibited the utilization of the intermediate.


1997 ◽  
Vol 30 (3) ◽  
pp. 175-185 ◽  
Author(s):  
A. Brusco ◽  
J. Pecci Saavedra ◽  
G. García ◽  
P. Tagliaferro ◽  
A. M. Evangelista de Duffard ◽  
...  

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