The 5' untranslated region of the Gossypium hirsutum
α-globulin B gene consists of the promotoer (1108 basepairs) and a
5' transcribed, untranslated sequence (36 basepairs) of the gene.
The promoter is seed-specific and confined to middle to late stages
of embryo development; only active at 15 days post-anthesis, during
the cotyledon expansion stage in the developing embryo and
increasing thereafter until embryo maturation.Transcripts under
transcriptional control of this promoter are found at high levels
in the dry seed. In contrast, the promoter is inactive in the stem,
leaf, root, pollen, and floral bud tissues. Additionally, water
stress does not induce transcriptional activity.