Single-celled cotton fiber (Gossypium hirsutum) provides a unique experimental system to study cell elongation. To investigate the role of the actin cytoskeleton during fiber development, 15 G. hirsutum ACTIN (GhACT) cDNA clones were characterized. RNA gel blot and real-time RT-PCR analysis revealed that GhACT genes are differentially expressed in different tissues and can be classified into four groups. One group, represented by GhACT1, is expressed predominantly in fiber cells and was studied in detail. A 0.8-kb GhACT1 promoter sufficient to ...
