Characterization and transcriptional profiles of two rice MADS-box genes

The plant MADS-box gene family plays a key role in plant development, espec ially in flower development. We designed degenerate primer according to the MADS-box conserved region and isolated two cDNA from rice, FDRMADS6 and FD RMADS7, which are homologous to AP1. RT-PCR expression analyses by using to tal RNA isolated from root, shoot and flower showed that the FDRMADS6 trans cript was detectable only in flower while FDRMADS7 was expressed in all thr ee tissues. In situ hybridization experiments indicated that at the early s tage of rice flower development, the transcripts of FDRMADS6 and FDRMADS7 w ere detected in the spikelet apical meristem, which were same as AP1. At th e late stage, when flower organ primordia started differentiating, the expr ession of FDRMADS6 appeared to be specifically localized in developing stam ens and the pistil primordia, while the transcripts of FDRMADS7 were detect able abundantly throughout the organ primordia. Our results suggest the two MADS-box genes may be members of the AP1 family, but may have different fu nctions. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.