The Agrobacterium oncogene AB-6b causes a graft-transmissible enation syndrome in tobacco.

摘要: Agrobacterium 6b oncogenes induce tumours and modify plant growth in various ways. Here we show that the AB-6b gene from strain AB4 placed under 2x35S promoter control (2x35S-AB-6b) induces a complex enation syndrome transgenic Nicotiana tabacum plants, also occurs few rare cases of genetic enations. In Arabidopsis thaliana, 2x35S-AB-6b induced radially symmetrical tubes on abaxial side leaves, which must therefore be considered as equivalents enations other species. Tobacco leaves contained small, supernumerary densely packed cells between spongy mesophyll epidermis, close to vascular strands arising at an early stage leaf development. On tobacco, could transmitted across graft junctions growing tissues untransformed both acropetally basipetally. We propose encodes synthesis one or more factor(s) are transported by phloem developing tissues.