FIG. 2.

virB mutants as donors of T strands during extracellular complementation. Overnight cultures were diluted to an optical density at 600 nm of 2.0. A 5-μl volume of a 1:1 mixture (2 × 10⁷ cells) of At10002 and the indicated virB mutants was inoculated onto a leaf surface wound created by scratching with an 18-gauge needle. The photographs were taken 30 days postinfection.