滇水金凤SAUR基因的克隆及表达分析

Cloning and Expression Analysis of SAUR Gene of Impatiens uliginosa Franch.

SAUR(small auxin up RNA)作为植物主要生长素诱导基因之一,其在促进植物细胞分裂和细胞伸长方面发挥重要的调节作用。该研究以滇水金凤(Impatiens uliginosa Franch.)为材料,采用RT-PCR等技术克隆SAUR基因,并进行生物信息学分析及基因表达分析。结果表明:(1)成功获得6个SAUR基因,其cDNA序列全长分别为351、534、396、333、309和411 bp,分别编码116、177、131、110、102和136个氨基酸。(2)生物信息学分析显示,除SAUR3为稳定蛋白外,其余5个均为不稳定蛋白;除SAUR5为疏水性蛋白外,其余均为亲水性蛋白;所有蛋白均为非分泌蛋白;6个SAUR基因编码的氨基酸序列与其他植物比对有较高的相似性,并具有一定的种属保守特征;推测SAUR4和SAUR5为旁系同缘,同时SAUR1、SAUR2、SAUR3和SAUR6为直系同缘。(3)RT-PCR分析发现,随着滇水金凤花的开放,6个SAUR基因表达量在花发育不同时期的檐部中均呈先上升后下降的趋势,始花期相对表达量最高,其次是盛花期,花苞期相对表达量均最低;各基因在花距的檐部和距部存在很大差异,其中SAUR3基因在2个部位均有非常高的表达;SAUR4、SAUR5和SAUR6基因在滇水金凤花距的基部和檐部具有相对高的表达,而其余3个SAUR基因在花距的尖部和弯部表达不明显。该研究结果为凤仙花属植物花距的生长发育调控机理、花型改良及新品种培育提供了一定的基础数据和科学依据。

SAUR(small auxin up RNA)is one of the main auxin inducing genes in plants,which plays an important regulatory role in promoting plant cell division and cell elongation.In this study,Impatiens uliginosa Franch.was used as material,and the SAUR gene was cloned by RT-PCR and analyzed by bioinformatics and gene expression.The results showed that the cDNA sequences of the six SAUR genes were 351,534,396,333,309 and 411 bp,encoding 116,177,131,110,102 and 136 amino acids,respectively.Bioinformatics analysis showed that SAUR3 was stable,and the other five proteins were unstable.All the proteins were hydrophilic except SAUR5 which was hydrophobic.All proteins are non-secretory proteins.The amino acid sequences encoded by these six SAUR genes had higher homology with other plants,and showed certain conserved characteristics of species.It is speculated that SAUR4 and SAUR5 are paratellate relatives,and SAUR1,SAUR2,SAUR3 and SAUR6 are direct relatives.Rt-PCR analysis showed that the relative expression levels of the six SAUR genes were the highest at the initial flowering stage,followed by the full flowering stage,and the lowest at the bud stage.SAUR3 gene was highly expressed in both spur and blade.SAUR4,SAUR5 and SAUR6 genes were highly expressed in the basel and blade of p.I.uliginosa Franch,while the other three SAUR genes were not significantly expressed in the tip and camber of I.uliginosa Franch.This study provided some basic data and scientific basis for the regulation mechanism of flower spacing,flower pattern improvement and new variety breeding of Impatiens.