DNA双链断裂修复模型（DSBR）是解释农杆菌介导的T-DNA整合的一种主流假说。该模型认为外源T-DNA通过DNA末端修复整合到植物基因组的双链断裂点（DSB）中，但DSBR模型中参与T-DNA整合的分子机理并不清楚。我们之前在拟南芥中发现的heterogeneous T-DNA整合现象显示T-DNA的两个末端能够分别整合到不同的DSB中，并引发DSB级联的错误连接。该现象支持DSBR模型，并暗示农杆菌通过劫持植物内源的DSB修复机制为T-DNA插入提供机会。在此研究基础上，本项目将通过在拟南芥基因组中引入邻近的DSB及3D-FISH等手段探究heterogeneous T-DNA整合的规律，以明确农杆菌侵染对植物内源DSB修复的影响。此外，我们将利用表达谱分析寻找T-DNA整合与植物DSB修复机制关联的分子证据。本项目的开展对揭示T-DNA整合及植物DNA修复机制均有重要意义。

DNA double-strand break repair (DSBR) pathway is a major model for T-DNA integration mediated by Agrobacterium. This model suggests that T-DNA would be incorporated into endogenous DNA double-strand breaks (DSBs) by DNA repairing. However, the molecular mechanism of the DSBR model is not fully understood. In our previous report of heterogeneous T-DNA integration, we demonstrated that two ends of a single T-DNA could be integrated into different DSBs, and this event would spike a cascade of wrong DSB repairs. Heterogeneous T-DNA integration supports the DSBR model and suggests that the machinery of DSB repair in plants would be hijacked by Agrobacterium. By means of introducing adjacent DSBs into the Arabidopsis genome and 3D-FISH, we intend to reveal more features of heterogeneous T-DNA integration and look for evidence of Agrobacterium’s influence on the plant’s DSB repair. In addition, analysis of differentially expressed gene based on RNAseq technique will be used to unravel the mechanistic relationship between T-DNA integration and DSB repair in plants. Our work would contribute to understand the mechanism of both T-DNA integration and DSB repair in plants.