三种植物线粒体基因低温差异表达比较分析

Comparative analysis of differential expression of mitochondrial genes in three plants at low temperature

关键词:  低温耐受性, 植物, 线粒体基因, 表达模式

Key words:  low temperature tolerance, plants, mitochondrial gene, expression mode

摘要:

线粒体作为植物细胞的能量代谢中心,在植物响应逆境胁迫中有重要的作用。该研究基于雪莲(Saussurea involucrata)、番茄(Lycopersicon esculentum)和拟南芥(Arabidopsis thaliana)三种不同低温耐受性植物的低温转录组。通过blast比对和数据库检索筛选相关物种的线粒体基因,使用PlantCARE在线网站分析启动子,使用mega7软件对系统发育树构建分析。结果表明:通过差异表达基因筛选,分别在雪莲、拟南芥、番茄中筛选出2、24、15个显著差异表达基因,主要包括线粒体核糖体亚基和电子传递链各复合体亚基,其中部分基因的低温差异表达情况如NAD1和NAD5,可能与植物的低温适应性有关; 通过表达模式的聚类分析,雪莲与拟南芥在基因的表达模式上相对于番茄更为相近,且不同类别的基因表达模式在不同物种间差异较大; 雪莲与其他菊科植物的呼吸链相关基因的蛋白序列具有很大差异,与万年藓(Climacium dendroides)、牛舌藓(Anomodon minor)等高山植物的进化距离较近。在整体上拟南芥、番茄和雪莲三种植物线粒体基因在低温响应上具有很大差异,表明线粒体基因及其表达调控与植物的低温耐受性之间存在一定的关联性。

Abstract:

As the energy metabolism center of plant cells, mitochondria play an important role in plant response to stress. To analyze difference in expression mode of mitochdria gene from the Arabidopsis thaliana, Lycopersicon esculentum and Saussurea involucrata, the differential expression genes(DEGs)was filtered in the three low temperature transcriptomes and comparison analysis was performed on the DEGs from three plants. All the mitochondria genes were filtered through blast against the mitochondria genomes that was downloaded from the NCBI database. Promoter analysis was performed through PlantCARE online website and the mega software was used to phylogenetic tree construction. The results were as follows: In total, there were 2, 24 and 15 DEGs were found in Saussurea involucrata, Arabidopsis thaliana and Lycopersicon esculentum, and these genes were mainly focused on mitochondrial ribosomal and electron transfer chain complex subunits; A few genes were seemed to relate to the cold adaptation that the expression level was positive to the ability of cold tolerance of the three plants, especially for the NAD1 and NAD5 gene; Through cluster analysis of expression patterns, Saussurea involucrata and Arabidopsis thaliana were more similar in genes expression mode than Lycopersicon esculentum, and the expression mode of different genes had a quite difference between different plants; Further analysis on the conserved motif sequence of these genes, the sequences of Saussurea involucrata showed more close relationship with the alpine plants such as Climacium dendroides and Anomodon minor than the other compositae plants. In general, the mitochondrial genes had a quite difference on the sequence of conserved motif and expression mode under the cold condition between the Arabidopsis thaliana, Lycopersicon esculentum and Saussurea involucrata. It was concluded that the mitochondria genes and its expressional regulation could be implicated in the cold adaptation of plants.