Crop Biotech Update

Molecular Cloning and Characterization of a Cytokinin Dehydrogenase Gene from Upland Cotton

May 20, 2011

Cytokinins are plant hormones that function in plant growth and development. Cytokinin dehydrogenease,  known as the main negative regulator in cytokinin metabolism of plants, irreversibly degrades cytokinins into adenine/adenosine moiety. Qi-wei Zeng, researcher at Southwest University, China, and colleagues cloned a CKX homologous gene (GhCKX) from upland cotton. The transgenic tobacco plants over-expressing GhCKX exhibited a typical cytokinin-deficient phenotype, while the plants with silenced CKX showed over-producing phenotype.

Reduction in cytokinin led to a significant decrease in fiber initials on a single ovule. Results of the study indicate that GhCKX codes for a functional CKX, and cytokinins could be necessary in the initiation of cotton fiber cells.

The paper published at the Plant Molecular Biology Reporter is available at