| isolation of a recombination deficient agrobacterium tumefaciens mutant. | the isolation of a recombination deficient (rec-) strain of agrobacterium tumefaciens is described. strain lba 4011 was mutagenized with nitrosoguanidine and after segregation 18,000 colonies were replica plated and uv irradiated. twentytwo uv sensitive strains were isolated and tested for methylmethanesulphonate (mms) sensitivity. six of these strains were more mms-sensitive than lba 4011. a ti plasmid that was genetically marked with tn 1 (cbr) was introduced in these strains and the rescue of ... | 1979 | 290851 |
| plant tumor reversal associated with the loss of foreign dna. | transformation of plant tissues into crown gall tumors has been associated with the transfer of a portion of a tumor-inducing plasmid (ti-plasmid) into plant dna. various laboratories have regenerated normal-appearing plants from a number of crown gall tumors. this study investigates the fate of the foreign dna in a series of tissues derived from various parts of a plant regenerated from the tumor bt-37 by braum and his coworkers. it was found that all the foreign dna sequences were lost from ti ... | 1980 | 7364453 |
| identification of agrobacterium strains by pcr-rflp analysis of pti and chromosomal regions. | chromosomes and ti plasmids of 41 agrobacterium strains, belonging to biovars 1, 2, 3, and agrobacterium rubi species were characterized by the restriction fragment length polymorphism of pcr-amplified dnas. profiles that were obtained by the analysis of the amplified 16s rdna confirmed the grouping of the strains according to their species. higher polymorphism was detected in the intergenic spacer between the 16s rdna and 23s rdna genes, allowing efficient discrimination of strains. identificat ... | 1994 | 7911654 |
| a new pcr system for agrobacterium tumefaciens detection based on amplification of t-dna fragment. | the design of the pcr system presented in this work is based on the knowledge of the molecular character of the crown gall disease. the virulence of agrobacterium tumefaciens requires the presence of a big (up to 235,000 bp) plasmid ti (pti-tumour inducing plasmid). this plasmid carries the so-called t-dna fragment (t-dna-transferred dna), which integrates into cell chromosomes of the infected plants and subsequently changes the plant morphology nad metabolism. in cannot be excluded that after t ... | 1997 | 9429288 |
| involvement of rad52 in t-dna circle formation during agrobacterium tumefaciens-mediated transformation of saccharomyces cerevisiae. | agrobacterium tumefaciens cells carrying a tumour inducing plasmid (ti-plasmid) can transfer a defined region of transfer dna (t-dna) to plant cells as well as to yeast. this process of agrobacterium-mediated transformation (amt) eventually results in the incorporation of the t-dna in the genomic dna of the recipient cells. all available evidence indicates that t-strand transfer closely resembles conjugal dna transfer as found between gram-negative bacteria. however, where conjugal plasmid dna t ... | 2014 | 24460832 |
| the transformation of zea mays seedlings with agrobacterium tumefaciens. | virulent strains of the soil bacterium agrobacterium tumefaciens infect dicotyledonous plants and elicit a profound neoplastic response which results in crown gall formation (18). the inciting agent has been shown to be a high molecular weight plasmid (ti) a section of which, the t-dna, integrates into the host plant's genome (4, 28, 30). although transformation of this kind was presumed to be limited to dicots, the detection of enzyme activities linked to the expression of t-dna has been demons ... | 1986 | 24302156 |