Identification and characterization of host factors important for Agrobacterium-eukaryote gene transfer

Abstract

Agrobacterium tumefaciens can transfer oncogenic T-DNA into plant cells in nature; it can also transfer DNA to yeast, fungal, and mammalian cells under laboratory conditions. In this study, it was shown that the yeast pheromone alpha-factor could increase the efficiency of Agrobacterium-yeast gene transfer by about 100 folds. This stimulation required the yeast genes responsible for the mating process, suggesting that an active process involving mating genes can enhance the competency of yeast cells to accommodate Agrobacterium T-DNA. Three pheromone responsive membrane trafficking systems were further identified to be involved in Agrobacterium-yeast gene transfer. This involvement of host membrane trafficking systems in T-DNA transfer was also observed in tobacco BY-2 cells. It was found that the T-DNA molecules extracted from BY-2 cells transformed by A. tumefaciens were protected by membrane structures. These observations indicate that membrane trafficking systems may represent a group of host factors important for Agrobacterium-eukaryote gene transfer.