烟草细胞色素P450的基因组学分析

Genome-wide analysis of cytochrome P450 monooxygenase genes in the tobacco

细胞色素P450是一类含血红素的单加氧酶超基因家族,在植物多种代谢途径中起着重要作用。为了解烟草中的P450的种类和数量,文章将植物代表性P450蛋白质序列与烟草基因组序列比对,在烟草基因组中鉴定了44个P450家族共263个成员。将这些烟草P450基因与烟草表达序列标签(EST)比对,发现173个成员有EST证据。通过与拟南芥中已知的P450蛋白序列比较,分析了部分烟草P450蛋白序列的特征和二级结构。根据烟草基因芯片数据和部分基因的RT-PCR结果,发现73个烟草P450基因能够在不同的生长发育时期表达,其中部分基因具有组织特异性。这些研究结果为烟草P450基因功能的深入分析奠定了基础。

Plant cytochrome P450 monooxygenases （CYP） constitute a large superfamily of heme-thiolate proteins, which are involved in a wide range of metabolic pathways. In this study, comparative genomic approaches were used to analyze tobacco CYP genes and their expression patterns. Based on analysis of the tobacco genomic DNA sequences that are currently available, 263 P450 genes that belong to 44 distinct clans were identified. EST evidence from 173 of the CYPs suggested that these genes are transcribed. Sequence features and secondary structures of the tobacco P450 genes were fur- ther analyzed through comparison with known P450 proteins. The expression profiles of 73 P450 genes were subsequently investigated by analyses of tobacco microarray data and RT-PCR. The results showed a variety of expression patterns of these genes in different tissues with a number of genes expressed in a tissue-specific manner. This study has set a founda- tion for further studies on functions of P450 genes in tobacco.