Isolation and characterization of a functional A-type cyclin from maize.

Cyclins are involved in the regulation of cell cycle progression in eukaryotes. We have isolated a cyclin cDNA clone, cycZm2w, from maize root tip cells, which fits best into group A2 of current plant cyclin gene classification schemes. The cDNA encodes a protein with a domain homologous to the cyclin box of mitotic cyclins. Complementation studies revealed that cycZm2w was able to rescue a budding yeast cyclin-deficient mutant (BF305-15d#21). As expected, cycZm2w is expressed in organs of the maize plant that possess meristematic activity, but is especially prominent in the proliferating regions of the root apex.