山新杨LTP家族基因生物信息学及表达模式分析

Bioinformatic Analysis and Expression Pattern of LTP Family Genes in Populus davidiana×P.alba var.pyramidalis

以山新杨(Populus davidiana×P.alba var.pyramidalis)LTP家族基因为研究对象,初步分析该家族基因的序列特征和表达模式,筛选材性和抗性相关PdbLTP基因,为LTP基因的分子调控机制研究及林木遗传改良提供候选基因。通过蛋白性质分析、多序列比对分析、进化树分析初步分析LTP家族基因的序列特征。利用荧光定量PCR(qRT-PCR)分析重力、NaCl及PEG胁迫处理下山新杨LTP家族基因的表达模式。查找获得8条PdbLTP基因序列,2条亚家族PdbGLTP基因序列。CDS序列长度在294~396 bp。LTP家族蛋白为疏水性蛋白且具有8个半胱氨酸的保守结构。qRT-PCR结果显示,PdbLTP1、PdbLTP3、PdbLTP5、PdbLTP7基因在应拉木中表达上调;PdbLTP1、PdbLTP2、PdbLTP3、PdbLTP5基因在茎中表达量最高;除PdbLTP5外,其它基因均受盐胁迫诱导;PdbLTP1、PdbLTP2、PdbLTP3、和PdbLTP5受干旱胁迫诱导。PdbLTP基因家族成员在调控山新杨木质部发育和抵抗非生物胁迫中发挥作用。

To lay a foundation for studying the molecular regulation mechanism of LTP family gene and molecular genetic improvement of Populus davidiana×P.alba var.pyramidalis,the expression pattern of LTP family genes from P.davidiana×P.alba var.pyramidalis was analyzed.The protein properties,multiple sequence alignments and phylogenetic tree analysis of LTP family members were performed to show their structural features.The P.davidiana×P.alba var.pyramidalis seedlings treated with gravity,salt and PEG stress respectively were subjected to quantitive real time PCR analysis.The expression patterns of PdbLTP family genes were carried out respectively.Eight PdbLTP genes and two subfamily PdbGLTP genes were obtained,and their CDS lengths were ranged from 294-396 bp.LTP family were hydrophobic proteins and had eight cysteine conserved structures,without transmembrane region.qRT-PCR analysis showed that the expression patterns of different PdbLTP family genes were different under gravity processing.Expression levels of PdbLTP1,PdbLTP3,PdbLTP5 and PdbLTP7 genes were up-regulated in tension wood compared to those in the normal wood.The transcripts levels of PdbLTP1,PdbLTP2,PdbLTP3,PdbLTP5 genes were abundant in stem.Expression of PdbLTP family genes was induced by salt stress except for PdbLTP5.PdbLTP1,PdbLTP2,PdbLTP3 and PdbLTP5 were up-regulated under drought stress.Different members of PdbLTP gene family play important roles in regulation of xylem development and tolerance to abiotic stress in Populus davidiana×P.alba var.pyramidalis.