Expression of a soybean β-conclycinin gene under the control of the Cauliflower Mosaic Virus 35S and 19S promoters in transformed petunia tissues.

A gene encoding the α'-subunit of β-conglycinin was ligated to the 19S and 35S promoters of Cauliflower Mosaic Virus and introduced into petunia plants on a disarmed Ti-plasmid using Agrobacterium tumefaciens. Transformed cells were regenerated into whole plants and ummunoreactive polypeptides and hybridizable, polyadenylated mRNA were detected in transformed tissues. Expression from the 35S promoter was 10 to 50 times greater than expression from the 19S promoter. The level of immunodetectable polypeptides was greater in seeds than in leaves or callus tissue. In addition, the pattern of α'-polypeptide breakdown products was distinctive in seeds and leaves. We conclude that in seeds the higher levels of the α'-polypeptide reflect enhanced stability of this protein.