Abstract：A full-length cDNA sequence of glycine-rich protein(GRP) gene, Sc-GRP, was obtained from sugarcane(Saccharum officinarum L.) leaf full-length cDNA library based on EST(expressed sequence tag) sequencing and bioinformatics analysis. Bioinformatics analysis revealed that this gene was 518 bp long including a 273 bp complete open reading frame(ORF), a 74 bp 5' untranslated region(UTR), and a 311 bp 3' UTR. Typical AATAA motif and poly(A) tail at the 3' UTR were also found. This gene corresponded to a 90 amino acid residues protein. The theoretical molecular mass and the theoretical isoelectric point of Sc-GRP was 10.12 kD and 5.86 respectively. Besides, glycine residue was found as the most abundant amino acids in Sc-GRP and reached 13%. Sc-GRP contained GGGX, GGX and GX motifs. No signal sequence or RNA binding region were found in Sc-GRP. Real-time PCR analysis showed that the expression of Sc-GRP in sugarcane mature leaves was much higher than that in young leaves, and increased with the mature degree of internodes in cane. However, Sc-GRP was hardly expressed in mature roots. Under the challenge of Al3+, the expression level of Sc-GRP gene went up firstly, and decreased subsequently in sugarcane primary roots. The result showed that the Sc-GRP gene is assumed to locate in cytoplasm and participate in the osmotic regulation of cell in sugarcane. This study aimed at understanding the functions of the Sc-GRP and providing basal information for its potential application in sugarcane molecular breeding.
