OsMADS13, a novel rice MADS-box gene expressed during ovule development

MADS-box genes have been shown to play a major role in defining plant archi tecture. Recently, several MADS-box genes have been reported that are highl y expressed in the ovule. However, only for the Petunia genes FBP7 and FBP1 1 has a function in defining ovule identity been shown. We have isolated a rice MADS-box gene named OsMADS13. Expression analysis has shown that this gene is highly expressed in developing ovules. In order to facilitate a det ailed characterization of rice ovule-expressed genes, a comprehensive morph ological description of ovule development in rice has been performed. The p redicted amino acid sequence of OsMADS 13 shows significant homology with Z AG2, a maize MADS-box gene, which is also expressed mainly in the ovule. Ma pping of the gene in the rice genome showed that it is located on chromosom e 12, which is syntenic to two maize regions where ZAG2 and iis paralogous gene ZMM1 have been mapped. Our results suggest that OsMADS13 is the orthol og of ZAG2 and ZMM1 and might play a role in rice ovule and seed developmen t. (C) 1999 Wiley-Liss, Inc.