Abstract
We have isolated all phytochrome mutants (phyA, phyB and phyC) from rice and have created phyABC triple mutants. The morphology of triple mutant was strikingly different from that of normal rice plants, which seems to substantially result from abnormal internodal elongation in the triple mutant. In WT the number of measurable internodes are 4 to 5 and the upper most internode being the longest. Whereas, phyABC triple mutants showed 7 to 8 internodes with almost the same lengths. The initiation of internodal elongation in rice is related to the shift from vegetative growth to reproductive phase. In phyABC triple mutants, such tight correlation seems to be relaxed and result in immature internodal elongation in the vegetative stage. These observations suggest that light signals mediated by phytochromes are necessary to suppress the internode elongation during the vegetative stage and this control should be very important for the normal morphogenesis in rice.
