Functional characterisation of plant NF-X1 type zinc finger proteins

人的核因子-X1蛋白和其他真核生物中的同源蛋白代表了一类转录因子，其特征是具有核因子-X1锌指模体。这些蛋白质发挥着不同的作用，如调节哺乳动物的炎症反应和控制果蝇的发育过程。我们已经鉴定出两个编码NF-X1型锌指转录因子的拟南芥基因，分别命名为AtNFXL1和AtNFXL2。AtNFXL1反义植株和atnfxl1 T-DNA敲除突变体在盐胁迫和渗透胁迫下生长和存活较差。AtNFXL2-反义植株、atnfxl2基因敲除突变体和AtNFXL1过表达植株在这些条件下的表现优于野生型植株。油菜素类固醇促进胁迫下的生长依赖于AtNFXL1蛋白。我们假设AtNFXL1和AtNFXL2基因在适应过程的调节中起拮抗作用。为了加深我们对植物NF-X1型锌指蛋白作用方式的分子基础以及油菜素骨蛋白在胁迫下的作用的了解，我们计划结合使用转基因、分子和生物化学方法。该项目的完成将增加我们对植物在胁迫下生长的分子基础的一般知识。

The human NF-X1 protein and homologous proteins in other eukaryotes represent a class of transcription factors which are characterized by NF-X1 type zinc finger motifs. The proteins play different roles, such as regulation of the inflammatory response in mammals and control of developmental processes in Drosophila. We have identified two Arabidopsis genes encoding NF-X1 type zinc finger transcription factors which we termed AtNFXL1 and AtNFXL2. AtNFXL1-antisense plants and atnfxl1 T-DNA knockout mutants show poor growth and survival under salt and osmotic stress. AtNFXL2-antisense plants, atnfxl2 knockout mutants, and AtNFXL1 overexpression plants perform better than wildtype plants under such conditions. Brassinosteroid-promoted growth under stress depends on the AtNFXL1 protein. We hypothesize that the AtNFXL1 and AtNFXL2 genes play antagonistic roles in the regulation of adaptive processes. To increase our understanding of the molecular basis of the mode of action of plant NF-X1 type zinc finger proteins and the role of brassinosteorid under stress, we are planning to use a combination of transgenic, molecular, and biochemical approaches. Completion of the project will increase our general knowledge of the molecular basis of plant growth under stress.