苹果属无融合生殖SERK1基因的克隆与生物信息学分析

[目的]为探讨苹果属植物无融合生殖分子机制。[方法]以苹果属平邑甜茶及杂种后代33#为试材,以苹果基因组CDS序列设计引物,通过PCR扩增技术克隆出SERK同源基因的cDNA全长序列,命名为MhSERK1和MhdSERK1(GenBank登录号JQ231273和JQ231272),利用实时定量RTqPCR的方法检测了这两个基因在平邑甜茶和杂种后代各组织和器官中的表达模式。[结果]序列分析显示MhSERK1和MhdSERK1编码区序列全长为1 899 bp和1 881 bp,分别编码632和626个氨基酸,其氨基酸序列与其他植物的SERK1同源基因所编码的氨基酸同源性都在80%以上,特别是与葡萄科龙眼品种同源性最高,高达92.56%,与模式植物拟南芥、烟草等植物的SERK同源基因都具有很高的同源性。实时定量PCR结果表明,在平邑甜茶和杂种后代不同组织、花器官中SERK1基因的表达量存在差异,其中在子房中的表达量最高,在营养生长的组织中表达量很低,在平邑甜茶花蕾期的子房中表达量最高。[结论]推测该基因在平邑甜茶和杂种后代的生殖发育过程中可能发挥重要作用。

Isolation and Bioinformatics Analysis of Apomicxis SERK1 Genes in Malus

The plants Malus hupehensis var. pingyiensis Jiang (Pingyi Tiancha) and a hybrid strain 33# were employed as the experimental materials. By PCR techniques and primers which were designed from the CDS sequences of apple genome, the full-length cDNA sequences of SERK homologous genes were cloned, which were named as MhSERK1 and MhdSERK1 (GenBank accession No. JQ231273 and JQ231272), and then SERKs expressions were detected in different tissues and organs of Pingyi Tiancha and the hybrid strain through Real-time quantitative PCR method. The results showed that the length of coding region sequences about MhSERK1 and MhdSERK1 were 1 899 bp and 1 881 bp, which respectively encoded 632 and 626 amino acids. Compared with other plants, the amino acid sequence homology of SERK1 was 80% or more, especially with Longan grape (Vitaceae), which could reach 92.56%, and it also had a high homology with the model plant Arabidopsis thaliana and tobacco. The results of real-time quantitative PCR showed that the expression levels of SERK1 gene were different among the different tissues and organs of Pingyi Tiancha and hybrid strain, which was high expression levels in the ovary, very low expression levels in vegetative tissues, and the highest expression levels in the ovary of the flower bud of Pingyi Tiancha, indicating that SERK1 gene played an important role in the reproductive and developmental processes of Pingyi Tiancha and hybrid strain.