root specific genes

[Maurizio Chiurazzi]

Dear Arabinetters,
I'm doing a T-DNA tagging project in the model legume Lotus japonicus
looking for genes that are expressed during the plant response to
Rhizobium. To decide about the size of the screening I have to do, it would
be very useful to me to know any information about the number of genes
specifically expressed in roots compared with the house-keeping ones. Do
you know if anybody has done a rough estimation of these number in
Arabidopsis or other plants?
thanks
Maurizio

Dr. Maurizio Chiurazzi
Intern. Instit. of Genet. and Bioph.
Via Marconi 10, 80135, Naples, Italy,
fax 39-81 5936123