• The Korean Journal of Pesticide Science
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• v.2 no.2
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• pp.97-101
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• 1998

Agrobacterium vitis causes a crown gall disease in grapevine and that is one of the major hindrances for the wide cultivation and production of grapevine. We studied the possibility of biological control using selected biological control agent. One isolate from the infected soil, named as strain 27, was able to inhibit the biovar 1; A. tumefaciens C58 and Ach5, biovar 2; A. rhizogenes 13264, and biovar 3; A. vitis, in vitro and in vivo test. The putative biological control agent, A. radiobacter strain 27 was carrying the plasmid and the size of isolated plasmid was very similar to that of pAgK84 of A. radiobacter K84.

• Journal of Plant Biology
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• v.39 no.3
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• pp.179-184
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• 1996

The purpose of this study is to obtain the most efficient combination of Agrobacterium tumefaciens strains and Ti plasmids for the construction of dicotyledonous plant vector system. Ti plasmid-curing A. tumefaciens A136 and KU12C3 were transformed with four kinds of Ti plasmids, pTiBo542, pTiA6, pTiKU12 and pTiAch5, respectively. The stems of 28 species of dicotyledonous plants were then inoculated with these transformants and examined for crown gall formation. The different combination of A. tumefaciens strains and Ti plasmids showed quite a difference in terms of the crown gall formation. Agrobacterium strins A136 and KU12C3 have a same plant host range in case that both strains harour the same kind of Ti plasmid, pTiBo542 or pTiAch5. However, the above-mentioned both strains have quite different host range in the event of containing the same Ti plasmid, pTiKU12 or pTiA6. In case that KU12C3 contains pTiA6 or pTiKU12, this strain has a wider plant host range than A136. The plant host range of pTiBo542 is the widest, followed by pTiA6, pTiKU12 and pTiAch5. Twelve plants among 28 tested plants are not transformed by any virulent Agrobacterium strains used in this study. In conclusion, A. tumefaciens KU12C3 and A136 harboring pTiBo542 showed the widest host range for transforming dicotyledonous plants. Also, it was acertained that the host range of Ti plasmids is affected by chromosomal level.

• Journal of Plant Biology
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• v.38 no.1
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• pp.19-24
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• 1995

The vir genes expression of Ti plasmid is induced by a family of related phenolic compounds. We investigated the effects of various phenolic compounds, Ti plasmids and hosts on the expression of the vir genes in the same type of octopine Ti plasmids, pTiKU12, pTiAch5 and pTiA6. The vir gene induction of pTiKU12 was remarkably stimulated by p-coumaric acid in relation to acetosyringone, but those of pTiAch5 and pTiA6 were more stimulated by acetosyringone than by p-coumaric acid. The effect of phenolic compound on the vir gene induction was different according to the kind of Ti plasmids. Also, the vir gene expression of A. tumefaciens KU913, which has pTiKU12 was about 6.2 times as much as that of A. tumefaciens KU915, which has pTiKU12 in KU12 host, in the presence of ferulic acid. But no difference was shown in the presence of p-coumaric acid. The vir gene induction abilities of phenolic compounds are different according to the kinds of phenolic compounds, Ti plasmids and hosts.

• Korean Journal of Microbiology
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• v.31 no.4
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• pp.292-299
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• 1993

Agrobacterium tumefaciens KU12 isolated from Korea is able to induce tumors on various plants and catabolize octopine as a sole carbon and nitrogen source. A, tumefaciens KU12 contains three plasmids. Their sizes are 45.5 kb. 240 kb. and > 240 kb. respectively. For the purpose of identification of octopine type Ti plasmid, avirulent A, tumefacients A136 is transformed with plasmids isolated from KU12 by direct transformation. Transformants containing Ti plasmid were grown on AB medium containing octopine as a sole nitrogen source. The isolated strain, named KU911, contains only 240 kb plasmid. As a result of induction of crown gall and Southern hybridization with other octopine Ti plasmid pTiAch5, 240 kb plasmid named pTiKU12 was Ti plasmid.

• KSBB Journal
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• v.7 no.3
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• pp.191-200
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• 1992

Several strains of Agrobacterium tumefaciens were isolated from soil in the Taegu area and characterized to develop some useful vector systems for higher plant genetic engineering. The selected colonies had a unique form, and strains from the colonies were capable of tumor formation on the sunflower leaf surface. They had a large plasmid. The restriction analysis showed that they were another kinds of Ti plasmic compared with C58 and Ach5. The isolated strains were identified as the nopaline type and also as biovar 1 A. tumefaciens, according to their tumor morphology, blophyslcal and biochemical characteristics. One of the isolated strains, AK204 was transformed with binary vector (pGA642), having selectable marker (Kmr, Tcr). Furthermore, maize tissue cells were transformed by cocultivation with AK204/pGA642, and the transformants were selected on the selective medium and identified using PAGE patterns of their soluble proteins.

• The Journal of Natural Sciences
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• v.4
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• pp.103-142
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• 1991

These studies were carried out to select somatic hybrid using selectable marker genes of Nicotiana glauca transformed by NPTII gene and Solanum tuberosum transformed by T- DNA, and to study characteristics of transformant. The results are summarized as follows. 1. Crown gall tumors and hairy roots were formed on potato tuber disc infected by A. tumefaciens Ach5 and A. rhizogenes ATCC15834. These tumors and roots could be grown on the phytohormone free media. 2. Callus formation from hairy root was prompted on the medium containing 2, 4 D 2mg/I with casein hydrolysate lg/l. 3. The survival ratio of crown gall tumor callus derived from potato increased on the medium containing the activated charcoal 0. 5-2. 0mg/I because of the preventions on the other hand, hairy roots were necrosis on the same medium. 4. Callus derived from hairy root were excellently grown for a short time by suspension culture on liquid medium containing 2, 4-D 2mg/I and casein hydrolysate lg/l. 5. The binary vector pGA643 was mobilized from E. coli MC1000 into wild type Agrobacteriurn tumefaciens Ach5, A. tumefaciens $A_4T$ and disarmed A. tuniefaciens LBA4404 using a triparental mating method with E. ccli HB1O1/pRK2013. Transconjugants were obtained on the minimal media containing tetracycline and kanamycin. pGA643 vectors were confirmed by electrophoresis on 0.7% agarose gel. 6. Kanamycin resistant calli were selected on the media supplemented with 2, 4-D 0.5mg/1 and kanamycin $100\mug$/ml after co- cultivating with tobacco stem explants and A. tumefaciens LBA4404/pGA643, and selected calli propagated on the same medium. 7. The multiple shoots were regenerated from kanamycin resistant calli on the MS medium containing BA 2mg/l. 8. Leaf segments of transformed shoot were able to grow vigorusly on the medium supplemented with high concentration of kanamycin $1000\mug$/ml. 9. Kanamycin resistant shoots were rooting and elongated on medium containing kanamycin $100\mug$/ml, but normal shoot were not. 10. For the production of protoplast from potato calli transformed by T-DNA and mesophyll tissue transformed by NPTII gene, the former was isolated in the enzyme mixture of 2.0% celluase Onozuka R-10, 1.0% dricelase, 1.0% macerozyme. and 0.5M mannitol, the latter was isolated in the enzyme mixture 1.0% Celluase Onozuka R-10, 0.3% macerozyme, and 0.7M mannitol. 11. The optimal concentrationn of mannitol in the enzyme mixture for high protoplast yield was 0.8M at both transformed tobacco mesophyll and potato callus. The viabilities of protoplast were shown above 90%, respectively. 12. Both tobacco mesophyll and potato callus protoplasts were fused by using PEG solution. Cell walls were regenerated on hormone free media supplemented with kanamycin after 5 days, and colonies were observed after 4 weeks culture.