马铃薯非特异性脂质转移蛋白基因StLTPa1的克隆和表达  

Cloning,Expression and Characterization of a Non-Specific Lipid Transfer Protein Gene from Potato

作　　者：郜刚[1,2] 任彩虹[3] 金黎平[1] 谢开云[1] 屈冬玉[1] 

机构地区：[1]中国农业科学院蔬菜花卉研究所 [2]山西师范大学生命科学学院,山西临汾041004 [3]山西师范大学生命科学学院

出　　处：《作物学报》2008年第9期1510-1517,共8页Acta Agronomica Sinica

基　　金：国家高技术研究发展计划(863计划)项目(2003AA207130);山西省自然科学基金项目(20051042)

摘　　要：非特异性脂质转移蛋白(nsLTP)是植物中大量存在的小分子脂类结合蛋白,具有多种生物学功能,如抗菌防御、信号传导、胞壁松弛、蛋白酶抑制等。通过接种青枯菌(Ralstonia solanacearum),从马铃薯栽培品种中薯3号中获得一个新的非特异性脂质转移蛋白cDNA克隆StLTPa1,序列分析表明该基因含636bp核苷酸,编码91个氨基酸,属于I类非特异性脂质转移蛋白。基于氨基酸序列构建的系统发生树揭示,该基因与其他茄科nsLTP具有高度保守的序列相似性,核酸和氨基酸水平分别具75%～85%和60%～92%的同源性。对该基因在互作早期基因表达时空性分析表明,StLTPa1基因不仅受病菌的诱导,在不同抗、感病的马铃薯基因型中差异表达,而且受一定浓度外源非生物激发子如水杨酸、茉莉酸和脱落酸的诱导并产生一定时间的持续效应,其诱导表达模式也表现出一定的差异。原位杂交结果显示StLTPa1主要在马铃薯茎、叶维管束系统的韧皮部细胞中表达。这些结果说明StLTPa1基因受病菌和非生物激发子诱导,在植物防御反应中发挥作用。Plant non-specific lipid transfer proteins （nsLTPs） are abundantlipid binding proteins with small molecules that play several biological roles including antimicrobial defense, signaling, cell wall loosening, proteinase inhibiting and so on. A new cDNA clone, named StLTPal, corresponding to potato nsLTP gene was isolated from a cultivated potato （Solanum tuberosum） infected with Ralstonia solanacearum. The sequence analysis encoded a type I nsLTP of 91 amino acids. The StLTPal gene showed that the cloned cDNA contained 636 bp nucleotide which is well conserved in the coding region with 60-92% identity at the amino acid level, and 75-85% identity at the nucleotide sequence level compared with other Solanaceae nsLTPs. The transcripts of the gene accumulated in potato leaf and stem tissues induced by R. solanacearum and showed dominant differential expression between resistant and susceptible genotypes. In situ hybridization results showed that the StLTPal mRNA was localized in phloem cells of vascular tissues in potato leaf and stem tissues after pathogen infection. Salicylic acid, methyl jasmonate and abscisic acid induced StLTPal gene expression in different manners. These three signal molecules could produce a long-term effect on the StLTPal gene expression during the early stages of potato-R, solanacearum interaction. These results thus showed that the StLTPal may be pathogen-responsive gene in plant defenses and involve in a complex gene regulation network.

关 键 词：马铃薯 非特异性脂质转移蛋白 StLTPa1 克隆 表达 

分 类 号：S532[农业科学—作物学]