巴西橡胶树蔗糖磷酸合成酶基因的克隆和表达分析

摘要

分析橡胶树EST数据库,得到一个注释为SPS(蔗糖磷酸合成酶)的EST序列重叠群(contig).通过PCR扩增和测序技术获得该基因的全长cDNA和基因组序列,命名为HbSPS1.序列分析显示,HbSPS1基因长度为5 298 bp,包含13个外显子和12个内含子.对应的cDNA编码序列(CDS)为3 156 bp,推测编码1 050个氨基酸,分子量大小为118.1 ku,等电点为6.05.采用荧光定量PCR技术分析该基因的表达模式,结果表明,HbSPS1基因主要在胶乳中表达,在乙烯利和机械伤害处理的胶乳中呈下调表达,在割胶影响下略有上调表达趋势,同时该基因在叶片发育过程中呈上调表达.说明HbSPS1基因可能参与胶乳蔗糖代谢和叶片发育调控.%Sucrose phosphate synthase is a key enzyme for sucrose synthesis in plant.One sucrose phosphate synthase gene,named as HbSPS1,was cloned based on the Hevea EST and genome sequence database1.Sequence analysis revealed that the CDS of HbSPS1 cDNA was 3 156bp long,encoding a peptide of 1 050 amino acids with molecular weight 118.1 ku,and pI 6.05.The HbSPS1 gene contained 13 exons and 12 introns.Tissue-specific expression analysis results indicated that the HbSPS1 was mainly expressed in latex.The expression of HbSPS1 was up-regulated with leafmaturation,showing higher expressions in adult leaves.The HbSPS1 expression was down-regulated in latex under wounding treatment,whereas slightly up-regulated under tapping.The results suggested that HbSPS1 played a role in regulating the sucrose metabolism in latex and correlates with leaf development.