About Thiadiazuron(TDZ) and Phosphinothricin(PPT)

[yamini]

Could working on plant tissueculture and genetic transformation answer my doubt.
I am trying to use TDZ to get transgenic shoots but my selection agent PPT seems to be sensitive. Even with very low PPT concentrations i am afailing to get shoots.
Can anyone help?

yamini

[mothorc]

PPT in low content is a plant regulator, and there are some interaction between them but I can't find any article about this problem
If it is too sensitive, why don't you use another hormone to regenerate shoot. TDZ just a group of both auxin and cytokinin.