3个毛白杨病程相关蛋白基因的克隆及表达

摘要

运用电子克隆及RT-PCR技术,以水杨酸(SA)和茉莉酸甲酯(MeJA)诱导下的毛白杨(Populus tomentosa Carr.)叶片总RNA为模板,分离获得3个病程相关蛋白基因,分别命名为PtPR-1、PtPR-5与PtPR- 10.生物信息学分析后发现,这3个基因所编码的蛋白PtPR-1、PtPR-5和PtPR - 10分别具有SCP、THN和Bet_v_1保守结构域,其中PtPR-1和PtPR-5均包含一段25bp的信号肽,成熟蛋白序列与其他物种相比同源性较高；而PtPR-10无信号肽,蛋白序列与其他物种相比差异性较大,其基因组序列还存在一段91 bp的内含子.另外,实时荧光定量PCR技术分析结果表明,SA和MeJA处理后,PtPR-1与PtPR-10表达模式和转录水平均有较大差异,而PtPR-5的表达则未见显著变化,由此可推测,PtPR-1可能受SA和JA双重诱导,而PtPR- 10可能只受SA诱导表达,在SA和JA两种信号通路的互作下,表现出不同的诱导表达模式.%Three pathogenesis related protein genes, named as PtPR-1, PtPR-5 and PtPR-10, were PCR-amplified from Populus tomentosa induced by salicylic acid (SA) and methyl jasrnonate ( MeJA) after in silico cloning. Their sequence structures and conserved domains of encoding protein were analyzed using bioinformatics tools, and the expression patterns of these genes in response to the treatment of SA and MeJA were investigated by real time quantitative RT-PCR. Results show that the conserved domains of SCP, THN and Bet_v_1 are contained individually in PtPR-1, PtPR-5 and PtPR-10, of which 25 bp signal peptide sequence was found in both PtPR-1 and PtPR-5, whose coding regions of mature protein have high similarity compared with other homologous sequences. However, PtPR-10, without signal peptide, shows more diversity and the genome sequence of which contains a 91 bp intron. Responded to SA and MeJA, the expression pattern and transcription level of PtPR-1 and PtPR-10 are quite different, but PtPR-S exhibits no significant change in expression. It is suggested that PtPR-1 might be 9ubject to the dual induction of SA and JA, but PtPR-10 only to SA, and the different interaction between SA and JA signaling pathways may be result in the differences discussed above.