论文部分内容阅读
抗坏血酸过氧化物酶(APX)在植物响应逆境胁迫中具有重要作用。根据苎麻转录组测序中的Unigene42508片段序列,通过RT-PCR结合RACE技术从中苎1号苎麻品种中克隆该基因的全长cDNA序列。BLAST分析表明,该基因编码蛋白属于植物过氧化物酶超家族成员,将其命名为BnAPX1。其cDNA全长为1201 bp,含有一个870 bp的开放阅读框,编码一个含289个氨基酸残基,分子量为31.4 kDa,等电点(pI)为5.88的假定蛋白。其氨基酸序列与与棉花(EU244478)、毛白杨(AY789051)、马蹄莲(AF159254)、大豆(AB331961)、豇豆(AY466858)和麻风树(GQ337076)的相似性分别为84%、82%、81%、79%、80%和82%。实时荧光定量PCR检测发现,BnAPX1基因在苎麻根、茎中段、茎尖、茎皮和幼叶各部位均有表达,其中,在苎麻幼叶中表达量最高,且受重金属镉胁迫诱导,显示BnAPX1在植物重金属镉响应中发挥作用。苎麻APX基因序列的获得与表达特性研究为探寻苎麻耐镉分子机理奠定了基础。
Ascorbate peroxidase (APX) plays an important role in plant response to stress. According to the sequence of Unigene42508 in the ramie transcriptome sequencing, the full-length cDNA sequence of this gene was cloned by RT-PCR and RACE from Zhongzhu 1 ramie. BLAST analysis showed that the gene encodes a member of the plant peroxidase superfamily and named it BnAPX1. The full-length cDNA was 1201 bp in length and contained an open reading frame of 870 bp encoding a hypothetical protein containing 289 amino acid residues with a molecular mass of 31.4 kDa and an isoelectric point (pI) of 5.88. The amino acid sequences were 84%, 82%, 81% identical to those of cotton (EU244478), Populus tomentosa (AY789051), calla lily (AF159254), soybean (AB331961), cowpea (AY466858) and Jatropha (GQ337076) , 79%, 80% and 82%. The results of real-time PCR showed that BnAPX1 gene was expressed in the roots, stem midsection, stem tip, stem bark and young leaves of ramie. The expression level of BnAPX1 in young ramie leaves was the highest and was induced by heavy metal cadmium stress. Plays a role in plant heavy metal cadmium response. The ramie APX gene sequence acquisition and expression characteristics of ramie cadmium resistance to explore the molecular mechanism laid the foundation.