Seventeen cDNA clones of genes corresponding to mRNAs expressed preferentially in floral organs of Arabidopsis thaliana were obtained by differential screening of a flower bud cDNA library, and classified into five groups (1A, 17A, 1B, 4B and 5B) by cross-hybridization and restriction analysis. Sequence analysis revealed that the 1A-1 and 17A-1 clones encode vegetative storage proteins (VSPs). The VSP mRNAs were detected in a small amount in leaves and increased to a limited level by wounding. Both 1B-1 and 5B-1 clones were homologous to transmembrane protein cDNAs. The protein encoded by 4B-1 clone contained a proline-rich region, but no homologous proteins were found in databases.