Light regulation of a SSRubisco-nos chimaeric gene: photoregulatory control sequences from a C3 plant function in cells of a CAM plant.

A SSRubisco-nos chimaeric gene has been constructed, in an oncogenic Ti-plasmid vector. A 900bp soybean SSRubisco upstream fragment, carrying CAAT and TATA boxes and transcription initiation point, was fused to the nos coding region, the fusion site being within the 5'-untranslated region. When this chimaeric construct was transferred to Kalanchoe cells, nos expression was shown to be light-regulated. Thus DNA sequences responsible for light-dark control of gene expression are wholly or partly contained within the 900bp soybean SSRubisco upstream region. Moreover, this is the first demonstration that photoregulatory elements in a gene derived from a C3 plant, function in cells of a plant exhibiting the CAM trait.