Cloning and expression of a new MADS-box gene from rice

A new full-length MADS-box gene named FDRMADS8 was isolated from rice (Oryza sativa L.) by 3'RACE and 5'RACE using degenerate primer designed according to the MADS-box conserved region. The analyses of cDNA sequence showed that FDRMADS8 has 1 406 bp and encoded 233 amino acids which displayed the structure of typical plant MADS-box protein. The deduced amino acid sequence showed that it shared 50% identity with AGL14 of Arabidopsis. The RT-PCR expression analysis results from rice root, shoot and newer showed that the FDRMADS8 transcript nas detectable in all three tissues, but the expression was lower in root and shoot. In situ hybridization experiments were performed on inflorescences and roots to analyze their temporal and spatial expression pattern. At the early stage of rice newer development, FDRMADS8 was mainly detectable in the bracts, bract hairs and inflorescence stems, while lower expression was detected in the apical meristem. Later in development, the expression of FDRMADS8 was detected in glumes and inflorescence stems. In root, the expression of FDRMADS8 was mainly localized in the elongation and mature region. No apparent expression signal was detected in the root cap, root meristem and pericycle cells. The results suggest that the MADS-box genes play a key role in the rice flower development though not restrict to it.