Photoregulated expression of a pea rbcS gene in leaves of transgenic plants.

A 2.4-kb pea genomic fragment, containing a member (rbcS-E9) of the multigene family encoding the small subunit (rbcS) of ribulose-1,5-bisphosphate carboxylase, was inserted into a non-oncogenic, Ti-plasmid vector and introduced into the genomes of Petunia hybrida (Mitchell) and Nicotiana tabacum (SR1) plants by in vitro transformation. Petunia and tobacco plants containing the introduced pea rbcS-E9 gene were regenerated from protoplasts. In these transgenic plants the rbcS-E9 gene is transcribed accurately using its own promoter and its expression is light-induced and organ-specific. A deletion mutant with 352 bp of 5'-upstream sequence still retains photoinducibility and leaf-specific expression. Clonal analysis of independent transgenic petunia plants revealed that chromosomal positions in the recipient plant genome affect the quantitative but not qualitative aspects of rbcS-E9 expression.