The isolation and characterisation of nuclear-encoded light-regulated genes from "Pisum sativum" and their expression in transgenic plants of "Nicotiana tabacum"

Genomic clones encoding a gene for the small subunit of ribulose-1,5-bisphosphate carboxylase oxygenase (SS47) and a gene encoding the major chlorophyll a/b binding protein (AB13) from Pisum sativum have been isolated and characterised. The genomic clone SS47 is shown to be the genomic equivalent of the cDNA clone SSU60 [Bedbrook, Smith & Ellis (1980) Nature 287, 692-697.] by hybridisation studies and sequence analysis. The complete sequence of SS47 and the partial sequence of AB13 are presented. The gene SS47 accounts for 50% of all small subunit transcripts in 9-day-old light-grown pea leaves. The degree of expression of the other members of the small subunit multi-gene family is also discussed. The gene AB13, or a highly homologous one, is shown to be expressed in 9-day-old light-grown pea leaf tissue. The characterised genes have been transferred, via an Agrobacterium Ti-plasmid binary vector to cells of Nicotiana tabacum. Transformed cells have been regenerated into whole plants. The degree of expression of the gene SS47 in transgenic tobacco plants is shown to be variable between plants, and ranges from zero up to levels comparable to its expression in pea plants. In the one transgenic plant containing ABl3 that was screened, no AB13 transcripts were detected. Studies on the transmission of the kanamycin-resistance marker to the progeny of transformed plants have shown that in all but one of these plants, segregation of this marker is in a typical Mendelian manner; a possible explanation is proposed and discussed for the non-Mendelian segregation of the kanamycin-resistance marker in the progeny of one transformed plant