• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.822-828
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• 2004

Nopaline-type Agrobacterium tumefaciens strain C58 cannot utilize octopine (Oct) as the sole carbon and nitrogen sources. This strain harbors two plasmids; a virulent plasmid, pTiC58, and a megaplasmid, pAtC58. From strain NT1, which is a derivative of C58 harboring only pAtC58, we isolated spontaneous mutants that utilize Oct as the sole nitrogen source. These Oct-catabolizing mutants, however, could not utilize the opine as the sole carbon source. In contrast, strain UIA5, a plasmid-free derivative of C58, could not give rise to such mutants. The mutations isolated from NT1 were mapped to socR in pAtC58, which is a negative regulator of the soc operon responsible for the uptake and catabolism of an Amadori opine, deoxyfructosyl glutamine (Dfg). A derivative of UIA5 carrying a clone of the soc operon with a transposon inserted in socR also utilizes Oct as the sole nitrogen source. However, UIA5 harboring the operon with mutations in each of the structural genes in the soc operon, socA, B, C, and D, lost the ability to generate spontaneous Oct-utilizing mutants, suggesting that soc genes in pAtC58 are required for the utilization of Oct as a nitrogen source, and that derepressed expression of these genes allows cells to utilize Oct. In contrast, Oct-catabolizing mutants derived from C58, which grew using Oct as the sole nitrogen source, could also utilize the opine as the sole carbon source. These mutants did not carry any detectable mutations in socR or the region upstream to the gene in pAtC58, suggesting that mutations occurring elsewhere in the genome, most likely in pTiC58, allow the uptake and catabolism of the opine.

• KSBB Journal
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• v.9 no.2
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• pp.157-164
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• 1994

Hairy root clones of Panax ginseng were established by selection of some hairy roots formed on the leaf, stem and root segments transformed with Agrobacterium rhizogenes strain $A_4$. The transformed roots grew well in MS medium under the dark condition. To confirm the transformation with Ri-T-DNA, dot blot hybridization and opine analysis were Performed. Among four hairy roots induced from different part of ginseng, the HB3 hairy roots were examined for selection of high-saponin-producing clones. Four clones isolated from HB3 hairy root cultures displayed various phenotypes characterized by growth and total saponin content. Maximum growth was obtained for cultures of HB3-10 clone and the content of total saponin was 0.55 wt%. However, higher amount of total saponin was obtained with HB3-2 clone cultures(0.74 wt%) in spite of lower growth. Dot blot hybridization confirmed the introduction of Ri-T-DNA in the plant genome. In the opine test, agropine and mannopine were detected from all hairy root clones.

• The Plant Pathology Journal
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• v.16 no.2
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• pp.55-62
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• 2000

No Abstract.See Full-text

• Journal of Plant Biology
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• v.39 no.3
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• pp.161-166
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• 1996

The hairy root cultures of Centella asiatica were established by infection leaf explants with Agrobacterium rhizogenes A4, 15834 in 1/2 Murashing and skoog liquid medium supplemented with 50 $\mu$M acetosyringone. The induced hairy roots were subjected to paper electrophoresis for the detection of opine and opine-positive clones which were considered to have been transformed. Five hairy root clones were selected according to the different bacterial strains used, growth rate and pattern. Among media tested, MS basal medium substituted phosphate concentration by 2.5mM K2HPO4 showed the highest growth rate in the dark condition.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2003.06a
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• pp.198-198
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• 2003

• Journal of Microbiology and Biotechnology
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• v.9 no.5
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• pp.637-645
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• 1999

Two putative regulator genes, mocR and mocS, of the moc (mannityl opine catabolism) operons in pTi15955 of the octopine-/mannityl opine-type Agrobacterium tumefaciens strain 15955, were tested for their possible roles as repressors in the moc operons. The regions upstream of macC and mocD, the first structural genes in the two divergently oriented moc operons, were transcriptionally fused into the promoterless lacZ reporter gene. Each of the lacZ-fusions was introduced into Agrobacterium strain UIA5, a Ti plasmid-cured derivative, harboring either a mocR or a mocS clone. The resulting strains were grown in media containing various sugar sources, and the $\beta$-galactosidase activities were quantitatively measured. The results suggested that MocR repressed the expression of macC and macD. The expression of the fused $\beta$-galactosidase was not induced by mannopine (MOP) or possible catabolic intermediates of the opine, e.g. santhopine (SOP), glucose, mannose, or glutamine. However, the repression was significantly relieved by the supplementation of MOP and the concomitant introduction of the agcA gene encoding MOP cyclase that catalyzes the lactonization of MOP to agropine (AGR). These results suggested that AGR, rather than MOP or the other catabolic intermediates, is the inducer for the expression of the operon. On the contrary to previous report showing that the induction levels of macC and macD were lowered by the supplementation of inorganic nitrogen in media, the expression of these genes was not affected by the level of nitrogen in our reporter system. MocS did not strongly repress the expressions of macC and mocD. It is possible that MocS may be involved in the regulation of the operons present downstream of the moc operon, which are responsible for the utilization of mannopinic acid and agropinic acid.

• Journal of Ginseng Research
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• v.15 no.2
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• pp.124-130
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• 1991

This study was conducted to obtain basic information about the transformation of ginseng tissue, identification of opine compound and protein, and saponin production from ginseng callus transformed with Ti-plasmic of AW$.$obacterium tumefaiens C58. Ginseng crown gall callus induced by pTiC58 could be continuously cultured on the Phytohormone-free medium. The transformation was reconfirmed by the detection and identification of opine compound, from the gall callus. The transformed ginseng callus contained higher amounts of protein than normal callus and the protein pattern of transformed callus was quite different from that of normal callus. The xylose which is not detected in the normal callus and ginseng root was identified in gall callus. The saponin contents of gall callus of ginseng were three times higher than that of normal callus, and ginsenoside composition of the transformed callus was similar to that of the cultivated ginseng root, but quite different from that of normal callus.

• Applied Biological Chemistry
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• v.38 no.2
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• pp.123-128
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• 1995

Several factors affecting on transformation efficiency were studied to establish a Agrobacterium rhizogenes mediated system for the transformation of Populus species, and We could obtaine tansgenic plantlets expressing the introduced gene. Leaf sections were more sensitive than stem sections to kanamycin and thought to be better material for transformant screening. The bacterial density did not affect on the efficiency of transformation over the range of $4{\times}10^5{\sim}7{\times}10^9\;cfu$. The optimum period for co-cultivation was one day or shorter. Both of the optimum concentrations of cefotaxime and ampicillin in the medium were $250\;{\mu}g/ml$ for elimination of bacteria from the inoculated leaf sections. The addition of acetosyringone in the bacterial culture medium increased transformation rate, and the highest rate was obtained at $50\;{\mu}M$ of acetosyringone. The transformed galls could be selectively induced and gown on the growth regulator-free medium or on the medium containing $100\;{\mu}g/ml$ or higher contrition of kanamycin. The roots were induced from the galls incited by A. rhizogenes within 3 weeks on the growth regulator-free medium as well as on the medium containing growth regulators. The plantlets were regenerated from the galls cultured for 6 weeks on the medium containing 0.05 mg/ml of NAA and 0.5 mg/ml of BA. The expressions of the introduced opine gene in the transformed galls and plantlets were confirmed by the analysis of agropine and mannopine.

• Journal of Ginseng Research
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• v.10 no.1
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• pp.45-54
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• 1986

These studies were carried out to obtain the basic information about transformation of ginseng plant by potential vector system, utilization of opine compound by Agrobacterium sap. , and initiation of crown gall tumor callus. Crown gall tumors were induced from stem of Panax ginseng C.A. Meyer by infection of Agrobacterium tumefaciens. Therefore, it was clarified that transformation of ginseng by Ti plasmid was possible. The crown gall tumors induced by Agrobacterium tumefaciens isolated. from the soil were different in a shape, size, and growth rate. Especially, infection of ginseng by Agrobacterium tumefaciens Y104 led to the amorphic tumor, Tumor tissue derived from stem crown gall could not be continuously cultured on the medium which did not contain phytohormone, and did not form the callus even on the medium supplemented with 2,4-D. On the other hand, the root crown gall tumors formed the calli but the formation rate of callus was quite low. As for the utilization of octopine and nopaline, it was found that 3 strains of Agrobacterium app., Y104, Y110 and C58, utilized nopaline only, Y109 utilized octopine, and Y101 failed to utilize either compound.

• KSBB Journal
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• v.4 no.3
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• pp.246-253
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• 1989

Hairy roots of carrot were induced by Agrobacterium rhizogenes $A_4$ strain within about 2-4 weeks after inoculated from root disc. Early axonic culture is established in RCM agar medium and following is in MS rigid medium. After 15 days culture, the hairy roots were vigrous growth in about 10 times of initial inoculum. Anthocyanin contents of hairy roots were more than of ordinary roots. 2, 4-D ($10^{-4}mg/ l$), sucrose (5%), nitrogen source (0.03M) contained medium was optimized to growth of hairy root and contents of anthocyanin. Phenotypic alterations of leaves are observed in transformed plants and determined the transformation of hairy roots and the transformed plants by opine assay.