中文摘要：

本研究在对甘蔗（Saccharum officinarum）叶片全长cDNA文库测序的基础上,通过EST（expressed sequencetag）序列测定和生物信息学分析,获得了1个编码富含甘氨酸蛋白（glycine-richprotein,GRP）基因的全长cDNA序列,命名为Sc-GRP。生物信息学分析表明,该基因全长518bp,包含一个273bp的完整开放阅读框（open reading frame,ORF）,5＇端非编码区（untranslated region,UTR）长58bp,3＇端UTR长187bp,且在3＇端UTR中有典型的加尾信号AATAAA和polyA结构。该基因编码长度为90个氨基酸的蛋白,其理论分子量为10.12kD,等电点为5.86。Sc-GRP中甘氨酸含量最高,达到13%,且包含明显的GGX和GX重复结构单元。Sc-GRP没有信号肽和RNA结合位点。定量PCR分析结果表明,该基因在成熟叶片中的表达量远高于其在心叶中的表达量。在甘蔗茎中,随着节间成熟度的增加,其表达量逐渐升高,但在成熟根中几乎没有表达。在铝盐胁迫下,该基因在甘蔗初生根中的表达先是升高,然后随胁迫时间的增加而下降。研究结果提示该基因定位于细胞质,参与细胞的渗透调节,本研究结果为该基因的功能解析及其在甘蔗分子育种上的应用积累了基础资料。

英文摘要：

A full-length cDNA sequence of glycine-rich protein gene（GRP）,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 58 bp 5＇ untranslated region（UTR）,and a 187 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 muchhigher 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 Al^3＋,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.