Mediation of flowering by a calmodulin-dependent protein kinase

A calmodulin-dependent protein kinase (MCK1) appeared important in regulati ng flowering in tobacco. The expression of modified MCK1 that lacks the C-t erminal including calmodulin-binding domain upsets the flowering developmen tal program, leading to the abortion of flower primordia initiated on the m ain axis of the plant and, as well, caused the prolongation of the vegetati ve phase in axillary buds. The abortion process of flowers began first in t he developing anthers and subsequently the entire flower senesces. In axill ary buds the prolonged vegetative phase was characterized by atypical elong ated, narrow, twisted leaves. These results suggested a role for calmodulin -dependent protein kinase homologs in mediating flowering.