中文摘要：

生长素结合蛋白（auxin binding protein,ABP）在生长素信号转导、植物生长发育调控等方面发挥重要作用。该研究利用RT-PCR方法从甘蔗品种Badila中克隆得到了1个ABP基因,序列分析显示该基因的开放读码框（ORF）长度为615bp,编码204个氨基酸。多序列比对和系统进化树分析表明它与高粱（Sorghum bicolor）和玉米（Zea mays）的ABP4蛋白的亲缘关系最近,因此将该基因命名为ScABP4。将其构建到原核表达载体pGEX-6P-1中,成功表达出一个分子量约为22.5kD的蛋白。亚细胞定位结果显示ScABP4主要定位于细胞质网状结构和细胞膜;生物信息学分析显示ScABP4是一个带有信号肽的分泌蛋白,说明ScABP4蛋白可能储存在内质网中并在质膜上执行其生物学功能。荧光定量PCR分析结果表明,ScABP4基因在甘蔗的芽、根、茎、叶中均有表达,其中在芽中相对表达量最高。生长素和黑暗处理下ScABP4基因的表达上调,说明ScABP4基因可能参与甘蔗对生长素的响应及与光信号通路的互作。此外,ABA、JA、SA、CuCl2胁迫能够诱导ScABP4基因的表达,CdCl_2胁迫可抑制ScABP4的表达。由此推测,ScABP4基因可能参与甘蔗对病害、干旱、渗透、重金属等胁迫的应答过程。该研究结果为探讨甘蔗生长素结合蛋白基因的功能提供了实验证据。

英文摘要：

Auxin binding protein（ABP）plays an important role in auxin signal transduction and the regulation of plant growth and development.To study the function and expression features of the ABPgene in sugarcane,we cloned an ABPgene from a sugarcane cultivar（Badila）using RT-PCR.Sequence analysis showed that it contained a 615 bp open reading frame（ORF）and encoded a deduced protein of 204 amino acids.It was designated as ScABP4 because of the multiple sequence alignment and phylogenetic tree analysis results revealed that it had closer relationships with ABP4 in Sorghum bicolor and Zea mays.It was cloned into the prokaryotic expression vector pGEX-6P-1and expressed a 22.5kD protein successfully in E.coli.Subcellular localization assay showed that ScABP4 protein is located in the reticular of cytoplasm and on the cytomembrane;protein structure prediction showed that it has a signal-peptide,speculate it may be stored in the endoplasmic reticulum,and exert its function on the plasma membrane.qRT-PCRshowed that ScABP4 expressed in bud,root,stem and leaf in sugarcane with the highest expression level in bud.ScABP4 was up-regulated by IAA or dark treatments indicated that ScABP4 might participate in sugarcane responses to auxin,and involved in light signaling pathway（s）.In addition,the expression of ScABP4 in sugarcane was induced by ABA,JA,SA and CuCl_2 but was down-regulated by CdCl2.These results indicated that ScABP4 might involve in the sugarcane resistance to disease,osmotic and heavy metal stress,which provides the basis for further studying the functions of ScABP4.