【作者】 李静；

【导师】 李伟；

【作者基本信息】 北京林业大学 ， 林木遗传育种， 2012， 硕士

【摘要】 牛枝子(Lespedeza potaninii)为豆科植物中最具耐旱特性的灌木树种之一,广泛分布于干旱、半干旱及草原荒漠地带,可作为研究基于单核苷酸多态性(SNP)水平的植物耐旱差异机制的材料。本研究以牛枝子为材料,研究了牛枝子LpDREB,LpP5CS基因组织表达及诱导表达规律,利用染色体步移及3’RACE技术克隆了LpDREB, LpP5CS基因,并进行了基因结构、系统进化、SNP分布及类型分析,同时对8个种源的300株牛枝子个体进行了生理生化指标的测量及分析。研究结果如下：1、牛枝子LpDREB基因cDNA序列长度为1611bp,具有957bp的开放阅读框,编码318个氨基酸,基因内部没有内含子：该基因同大豆GmDREB3基因的同源性最高；干旱胁迫诱导LpDREB基因在牛枝子的根、茎及叶中表达；本研究共检测到23个SNPs位点,其中有12个转换,11个颠换。编码区内的17个SNPs位点中,9个属于同义突变,8个为非同义突变。2、牛枝子LpP5CS基因DNA序列长度为6194bp,cDNA序列长度为2148bp,可编码716个氨基酸残基的蛋白质；该基因编码的氨基酸序列同大豆GmP5CS、四季豆PvP5CS等的氨基酸序列具有较高的同源性；LpP5CS基因在不同组织中的表达水平同对照组相比均有不同程度的改变；长度为6194bp的序列中共有SNPs位点176个,其中有113个转换,62个颠换,编码区内的43个SNPs位点中19个为同义突变,错义突变23个3、牛枝子8个种源脯氨酸含量,丙二醛含量及电导率的方差和分量分析显示,三个生理指标均有极显著差异,多重比较结果表明丙二醛含量及电导率的测定对于8个种源间多态性的分析更有意义。本研究为基于单核苷酸多态性的牛枝子抗旱机制的研究提供了重要的理论依据。更多还原

【Abstract】 Lespedeza potaninii is one of the most drought tolerant legumes species which naturally distributed in arid, semi-arid and desert grassland. It is a plant model for the investigation of the individual difference of drought tolerant at single nucleotide polymorphisms (SNP) level. In the present study, the gene LpDREB, LpP5CS were cloned from the L. potaninii plants by chromosome walking and3’RACE method. The organ-and inducible-expression patterns of the LpDREB, LpP5CS gene were also revealed. Furthermore, the structure of the gene and its phylogeny and SNP type and distribution were characterized. The results areas following:(1) The full length cDN A sequence of LpDREB gene was1611bp containing a957bp open reading frame (ORF) which encodes a318amino acid residues, no intron was found in gene. Phylogeny analysis revealed that the LpDREB gene had a closest evolutionary relationship with soybean GmDREB3gene. Expression of the LpDREB gene could be induced by drought stress in all tested organs. In the L. potaninii population,23SNPs were detected. A total of12SNPs were in transitions, while11SNPs were in transversions. For the coding region located17SNPs,9were synonymous mutation and8were non-synonymous mutations.(2) The full length DNA and cDNA sequence of LpP5CS gene was6194bp and2148bp encoding a716amino acid residues. The amino acid sequence of the LpP5CS gene had a closest homology with soybean CinP5CS and kidney bean PvP5CS gene. Expression of the LpP5CS gene varied in different organs compared with the control group.176SNPs were detected from the sequence of LpP5CS and113SNPs were in transitions, while62SNPs were in transversions. For the coding region located43SNPs,19were synonymous mutation and23were non-synonymous mutations.(3) Variance and component analysis of proline, malondialdehyde content and electric conductivity from8natural provenance of Lespedeza potaninii show that the three physiological indexes have very significant difference, multiple comparison results show that the measuring of malondialdehyde content and conductivity have more meaningful for polymorphism analysis between eight provenance.All these results provided the important theory foundation for study of drought tolerance mechanism based on single nucleotide polymorphism in Lespedeza potaninii.更多还原