Molecular characterization of RA68 related potentially to rice flower development

Abstract

One cDNA whose corresponding mRNA was preferentially accumulated in rice flowers was isolated by PCR-mediated RNA subtraction hybridization and RACE strategy. This gene, termed RA68, consists of three exons and two introns. the putative RA68 protein contained 219 amino acid residues with a putative signal peptide and two domains. The N-terminal domain is hydrophilic and rich in proline and threonine embedded in PTPTSYG motifs. The C-terminal domain is hydrophobic. Southern blot and sequence analysis reveal that RA68 exists as one copy in the rice genome and localizes in chromosome 2. Northern hybridization indicates that RA68 is expressed preferentially in buds and flowers, but not in roots and leaves. Furthermore, in situ hybridization indicates that RA68 transcripts are present in pollen mother cells (PMCs), dyad cells, uninucleate pollens and macrospore sacs. Possible functions of RA68 during the flower development are discussed based on its expression and protein structure characteristics.