Open AccessAssociation of single-stranded transferred DNA from Agrobacterium tumefaciens with tobacco cells.
Author(s) -
Vidadi Yusibov,
Todd R. Steck,
Vibha Gupta,
Stanton B. Gelvin
Publication year - 1994
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.91.8.2994
Subject(s) - agrobacterium tumefaciens , acetosyringone , biology , transfer dna , ti plasmid , dna , protoplast , plasmid , operon , bacteria , lysis , plant cell , microbiology and biotechnology , gene , mutant , transformation (genetics) , genetics
During the inception of crown gall tumorigenesis, the transferred DNA (T-DNA) is processed from the Ti (tumor inducing) plasmid of Agrobacterium tumefaciens and is transferred to plant cells. T-DNA processing and transfer require the induction of vir (virulence) genes by phenolic compounds secreted by wounded plant cells. After vir gene induction, both single-stranded (T-strands) and double-stranded forms of processed T-DNA accumulate in the bacteria. Although current models favor the transfer of T-strands to plants, there has yet been no experimental evidence to show this. In this paper, we show that T-strands disappear from acetosyringone-induced A. tumefaciens within 30 min of bacterial cocultivation with tobacco protoplasts. PCR analysis of T-DNA associated with protoplasts indicates that single-stranded, but not double-stranded, T-DNA can be detected in the plant cells within 30 min of bacterial cocultivation. Control experiments show that this T-DNA does not originate from lysed contaminating bacterial cells. T-DNA transfer depends on a functional bacterial virB operon. Protoplast infections using an A. tumefaciens virE mutant result in a low level of accumulation of T-strands in the plant cells.