小金海棠转录因子MxbZIP10响应低铁胁迫的分子机理

The bZIP TFs regulate genes which involved in plant growth，development，and response to abiotic and biotic stresses. However，the role of bZIP TFs participate in the regulation genes involed in low iron stress is still unknown.Three EST of bZIP TFs（bZIP10，bZIP98，HBP1-b）were selected by screening a subtractive library of Malus xiaojinensis including 1,152 clones. Expression pattern of MxbZIP10 were validated with RT-PCR, of which indicated that this gene somehow functioned in regulation genes involved in Fe absorption in apple tree. In order to search target genes directly regulated by MxbZIP10, chromatin immunoprecipitation（ChIP）will be employed, and screening proteins which interact with MxbZIP10 protein through Yeast Two-Hybrid System. Relationship of MxbZIP10, target genes and genes encoding proteins interact with MxbZIP10 also will be made clear. Network model of genes controlled by MxbZIP10 will be constructed for analysis the molecular mechanism of MxbZIP10 response to low iron nutritional stress. All of the above work mine iron efficient gene resource will be propitious to modify fruit tree via biotechnology breeding.

bZIP家族转录因子参与调控植物生长、发育过程以及生物胁迫和非生物胁迫反应，但是并未见到有关该家族基因调控低铁胁迫反应的报道。通过筛选小金海棠缺铁消减杂交文库，我们首次发现了了该家族的2个EST（bZIP10，bZIP98，HBP1-b）参与了小金海棠缺铁胁迫应答反应。从小金海棠中克隆MxbZIP10 cDNA，该基因受到低铁胁迫时在小金海棠根中加强表达。本项目旨在利用染色质免疫共沉淀（ChIP）技术寻找MxbZIP10转录因子直接调控的铁高效靶标基因；利用酵母双杂交技术筛选与转录因子MxbZIP10相互作用的候选蛋白；查明在缺铁胁迫处理前后，转录因子MxbZIP10、靶标基因和编码互作蛋白的基因之间的协同表达关系；并综合生物信息学方法构建基因间的相互作用网络模型，解析MxbZIP10调控的缺铁胁迫应答分子机制，以挖掘小金海棠铁高效基因资源，为开展生物技术育种改善果树铁营养工作奠定基础。