拟南芥GA2ox基因家族启动子分析

Promoter analysis of GA2ox gene family in Arabidopsis thaliana

赤霉素是一类重要的植物激素,它参与调节植物生长发育的各个阶段。真核基因的表达受多种因素的调控,其中启动子在转录水平上的调节作用至关重要,但是目前对拟南芥GA2ox基因家族上游顺式元件的详细分析较少。本研究分析了AtGA2ox基因家族染色体定位、进化关系、蛋白模体以及顺式元件。分析结果表明:AtGA2ox基因家族分为2个亚类;具有相对集中的染色体分布;具有相似的内含子和外显子结构;AtGA2ox基因家族成员进化关系越相近,模体和顺式元件则越保守且分布位置更接近。PLACE和Plant CARE以及DMB分析显示,AtGA2ox基因家族存在许多保守元件,受多因素的调控,在此家族的上游调控区域普遍存在组织和器官特异性表达元件、光响应元件、激素响应元件以及其他环境响应元件。基因表达谱分析结果表明,在激素诱导下,AtGA2ox基因家族均有响应。这些元件不仅作为正调控元件,诱导部分AtGA2ox基因的表达,而且还能作为负调控元件,抑制其他AtGA2ox基因的表达。

Gibberellin is one of important endogenous hormones in plant, and involves in regulating plant growth and development. Gene expression in eukaryote is regulated at multiple levels, especially at transcriptional level. At present, few studies have been done about the upstream cis-elements of AtGA2ox gene family. In this paper, chromosomal localization, evolution, protein motifs and cis-elments of AtGA2ox were analyzed by bioinformatics methods. The results showed that AtGA2ox gene family could be divided into two subclasses, and had relatively concentrated chromosomal localization, analogous introns and exons. It also revealed that members of the AtGA2ox gene family which have shorter genetic evolutionary distance would perform more conservative and have closer motifs and cis-elements. PLACE, Plant CARE and DMB analysis results indicated that there were a lot of conservative elements in the promoter sequence of AtGA2ox gene family, including tissue and organ-specific elements, light responsive elements, phytohormone and environment responsive elements. Gene chip data showed that expression of AtGA2ox responded to all kinds of hormone induction, indicating that these cis-elements not only act as positive regulatory elements to induce some AtGA2ox genes expression, but also can be used as negative control elements to inhibit other AtGA2ox genes expression.