论文部分内容阅读
APETALA1(AP1)基因既是花分生组织特征基因又是花器官形成发育基因,在花发育过程中起着关键作用。根据Genbank已知的AP1同源基因序列设计合成一对简并引物,以小黑杨(Popu-lus simonii×P.nigra)cDNA为模板,采用PCR方法分离克隆得到一个AP1同源基因全长,推测是小黑杨AP1基因,命名为XxAP1(GenBank accessionNo.XM_002316040.1)。XxAP1编码249个氨基酸,开放阅读框长度747bp,蛋白质分子量28.67kD,等电点9.45。同源性分析表明,它们的核苷酸序列与其他木本植物的AP1同源基因的一致性达70%以上,推测它们具有相似功能。试验分析表明,XxAP1第1至第60个氨基酸为MADS盒结构域,说明XxAP1蛋白以序列特异方式与DNA结合,具有转录调节因子功能,第75至174个为K盒结构域,它负责蛋白质与蛋白质间的相互作用,其大多数氨基酸具有亲水性,使XxAP1蛋白具有较好的水溶性,促进蛋白的流动性有利于基因的转录。采用半定量RT-PCR技术检测XxAP1在雄花芽发育过程中的表达模式,结果显示从9月到12月,XxAP1在小黑杨雄花芽中同一水平表达,自翌年1～3月表达量有下调趋势,说明小黑杨在花器官原基形成和花器官分化时期XxAP1持续稳定表达,在花器官生长时期XxAP1表达量有下调趋势。
APETALA1 (AP1) gene is not only a flower meristem-specific gene but also a floral organ-forming gene, which plays a key role in flower development. A pair of degenerate primers was designed and synthesized according to the AP1 homologous gene sequence known from Genbank. The full-length AP1 homologous gene was isolated and cloned by PCR using Popu-lus simonii × P. nigra cDNA as a template, Speculated that Populus tomentosa AP1 gene, named XxAP1 (GenBank accessionNo.XM_002316040.1). XxAP1 encodes 249 amino acids with an open reading frame of 747 bp, a protein molecular weight of 28.67 kD and an isoelectric point of 9.45. Homology analysis showed that their nucleotide sequences were consistent with AP1 homologous genes of other woody plants more than 70%, suggesting that they have similar functions. Experimental analysis showed that the 1st to 60th amino acids of XxAP1 are MADS box domains, indicating that XxAP1 protein binds to DNA in a sequence-specific manner and functions as a transcriptional regulator. The 75th to 174th K boxes are responsible for protein and The interaction between proteins, most of its amino acids are hydrophilic, so that XxAP1 protein has good water solubility, and promote protein flow conducive to gene transcription. Semi-quantitative RT-PCR was used to detect the expression pattern of XxAP1 during the male flower bud development. The results showed that XxAP1 was expressed at the same level in male flower buds from September to December, and the expression decreased from January to March next year , Which indicated that P. xylostella sustained and stable expression of XxAP1 during the period of flower organ primordium formation and flower organ differentiation. The expression of XxAP1 in flower organs was down-regulated.