Proximal Promoter Sequences of Sunflower Helianthinin Genes Confer Regionalized Seed-Specific Expression

Abstract

Summary DNA elements involved in the regulation of two sunflower helianthinin genes were identified by analysis of α -glucuronidase (GUS) expression in transgenic tobacco driven by sequences derived from the 5' upstream regions of these genes. We previously showed that a 2.4-kb upstream region of the helianthinin gene Ha G3-A conferred seed-specific GUS expression in transgenic tobacco (Bogue et al., 1990). A 5' deletion series of the helianthinin promoter identified a proximal promoter region that conferred significant regionalized GUS expression in seeds but not in leaves of transgenic tobacco. Three sequence motifs that bind to seed nuclear proteins were identified in the proximal promoter region. Mutations in these motifs significantly reduced the level of nuclear protein binding and the level of seed-specific expression.