Light-regulated expression of a pea ribulose-1,5-bisphosphate carboxylase small subunit gene in transformed plant cells

A pea nuclear gene encoding the small subunit of ribulose-1,5-bisphosphate carboxylase was inserted into the tumor-inducing (Ti) plasmid of Agrobacterium tumefaciens and transferred into petunia cells by in vitro transformation. The transferred pea rbcS gene is expressed in petunia cells under the transcriptional control of its own promoter in a light-dependent fashion similar to that observed in pea leaves. In contrast, a nonphotosynthetic chimeric gene containing a nopaline synthase promoter is expressed constitutively in both light- and dark-grown tissues. In the transformed cells, transcripts from the pea rbcS gene are processed correctly and translated to yield an authentic pea small subunit polypeptide which is localized in chloroplasts.