番茄GRAS家族SlSCL32基因调控果实成熟的机制研究

The transcription factors play important roles in regulation of gene expression. As one kind of transcription factors which exclusively exists in plants, the GRAS proteins are essential for the development of a wide range of plant species in regulation of signal transduction by gibberellin and light. SlSCL32, a new member of the GRAS family, was proved to be not only the target gene of key regulator RIN, but also involed in the ethylene related pathway. However, the specific function of this gene remains unkown. In this project, the model material of fruit tomato will be employed, the function of SlSCL32 gene will be characterized. By transformation with the over-expression vector and RNA interference vectors with contitutive (35S) and fruit-specific promoter (E8), the regulation feature of fruit ripening by SlSCL32 will be revealed. The taget genes of SlSCL32 will be screened by ChIP-seq technology, and the regulation network of SlSCL32 on tomato fruit ripening will be defined. The result is very useful for understanding the interactions among gibberellin, ethylene and light regulation pathways during fruit ripening. Futhermore, novel genetic resources could be provided to improve the quality of fruit via genetic modification. Therefore, this project has theoretical and practical importance.

转录因子是一类调控基因表达的重要因子。GRAS蛋白作为一类植物特有的转录因子家族，通过调节赤霉素和光信号转导在多种植物生长发育过程中发挥重要作用。SlSCL32基因是GRAS转录因子家族的一个新成员，已证明是果实成熟关键调控因子RIN的靶基因并与乙烯相关，但目前对其具体功能尚不清楚。本项目拟以模式植物番茄为材料、SlSCL32基因为研究对象，构建超表达载体、组成性（35S）和果实特异性（E8）RNAi干扰载体，通过转基因技术分析番茄SlSCL32对果实成熟的调控作用；采用ChIP-seq技术，筛选出SlSCL32的下游靶基因；揭示SlSCL32基因对番茄果实成熟的调控作用及机制。研究结果不仅可为深入了解果实成熟过程中赤霉素、乙烯、光因子之间的互作机制奠定理论基础，还可为利用基因工程技术进行果实类作物品质改良提供新的基因资源。因此，具有重要的理论价值和应用前景。

SlSCL32基因是GRAS转录因子家族的一个新成员，已证明是果实成熟关键调控因子RIN的靶基因并与乙烯相关，但目前对其具体功能尚不清楚。本项目拟以模式植物番茄为材料、SlSCL32基因为研究对象，构建超表达载体、组成性（35S）和果实特异性（E8）RNAi干扰载体，通过转基因技术分析番茄SlSCL32对果实发育和成熟的调控作用；发现SlSCL32干扰植株中在破色后四天和八天时胡萝卜素和番茄红素的含量有下降；经过q-PCR,检测参与番茄色素合成和乙烯调控途径中的重要基因，发现其中βLCY1基因出现一致下调的趋势，结合之前胡萝卜素和番茄红素下调的结果，推测SlSCL32在番茄成熟过程中与色素调控途径相关。乙烯相关的典型基因在转基因株系中未发现有显著的区别，但在未来的研究中可结合转录组测序的方法，全面分析SlSCL32表达被抑制后对番茄果实发育的影响。已经获得带有GFP融合标签的SlSCL32超表达植株，供后续ChIP-Seq实验运用。