Tissue-specific and light-regulated expression of a pea nuclear gene encoding the small subunit of ribulose-1,5-bisphosphate carboxylase.

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Abstract
We have examined the expression of a member of the multigene family encoding the small subunit (rbcS) of ribulose‐1,5‐bisphosphate carboxylase in various tissues of pea. The rbcS gene, pPS‐2.4, was characterized by DNA sequence analysis and 5′ and 3′ end mapping of its mRNA transcript. rbcS polypeptides were shown to be differentially present in various tissues of light‐ and dark‐grown plants. Northern analysis shows that compared with green leaves, the level of rbcS mRNA is reduced to approximately 50% in pericarps, 8% in petals and seeds, and 1‐3% in etiolated leaves, stems, and roots. 5′ S1 nuclease mapping of total rbcS mRNA was used to quantitate the relative amount of pPS‐2.4 gene‐specific transcripts in each tissue. pPS‐2.4 mRNA accounts for approximately 30‐35% of total rbcS transcripts in green leaves, but only 5‐10% in pericarps, 15‐20% in seeds, and is below detection in petals and etiolated leaves. We conclude that the pPS‐2.4 gene is expressed in a tissue‐specific, light‐regulated fashion and that transcriptional controls of individual rbcS genes vary.