ONCOGENE ARRANGEMENT IN A SHOOTY STRAIN OF AGROBACTERIUM-TUMEFACIENS

The Agrobacterium tumefaciens nopaline strain 82. 139 induces non-tera togenic shooty tumours on several plant species. We have determined th e position of the T-region oncogenes in a 11.4 kb Xba I fragment which shows a general organization similar to its pTiC58 counterpart. Seque nce analysis of the 4.7 kb right part of this fragment allowed us to i dentify the pTi82.139 ipt, 6b and nos coding sequences. pTi82.139 lack s the 6a gene, which lies between the ipt and 6b genes in pTiC58. The intervening region between the 6b and the nos genes contains an additi onal ORF with homology to ORF 21 (transcript 3') from the TR-DNA of oc topine strain pTi15955.