in-planta transformation question

[Irene]

I have a question regarding the in -planta transformation protocols.   

I notice that both the protocols from Hong-Gil Nam's lab, and the modified
one from Chris Sommerville's lab both use a double- inoculation technique
(ie, the primary inflorescence bolt is cut twice, and the wound site is
twice inoculated with agrobacterium).  I was wondering what the rationale
behind the double-inoculation was?   It seems to me that it might just
increase the chances of getting a double insertion, and wouldn't
necessarily increase the numbers of meristems transformed, but I could
easily be mistaken on this issue.  Anybody have any answers?

Any advice or updates on this technique would be much appreciated.  Also, I
would be very interested in hearing about anyone who has tried it on other
species (esp. other plant families) , as I am actually going to be trying
to transform Catharanthus rosea (a notoriously difficult plant to transform
and regenerate - hence the attempts to use non-tissue culture procedures).

I will compile and post the answers.  Thank you very much for the advice.

Irene Shonle