Identification of cotton SKP1-like gene GhSKP1 and its function in seed germination and taproot growth in tobacco

Abstract

Hu, D-L., Chen, Q-Z., Zhang, C-J., Wang, Y., Zhang, B-J. and Tang, C-M. 2013. Identification of cotton SKP 1-like gene GhSKP1 and its function in seed germination and taproot growth in tobacco. Can. J. Plant Sci. 93: 817-825. The SKP1 (S-phase kinase-associated-protein1) protein, a key component of the SCF (SKP1-CUL1-F-box protein) ubiquitin ligase complex, has been reported to play many important roles in many organisms, including regulation of ubiquitin-mediated protein degradation, seed germination, taproot growth and auxin signaling, though no study of this gene in cotton has been performed. In this study, a SKP1 gene was isolated from upland cotton (Gossypium hirsutum L.) using the rapid amplification of cDNA ends (RACE) method and was named Gossypium hirsutum SKP1 (GhSKP1). The cDNA sequence of GhSKP1 was 813 bp containing a 474 bp open reading frame, encoding a protein of 156 amino acids with a predicted molecular weight of 17.63 kDa. The deduced amino acid of GhSKP1 had a conserved SKP1 domain. GhSKP1 expression was tested in all organs of cotton plants, and the strongest expression was observed in stamens and radicles that have actively dividing cells. Overexpression of the full-length GhSKP1 cDNA in tobacco caused delayed seed germination and shortened taproots. Our results suggest that the presence of functional conservation between GhSKP1 and SKP1 in plant developmental processes may exist.