硝态氮转运蛋白（NRT）基因在调控作物氮效率方面具有重要作用，而丛枝菌根真菌分泌的信号物质（Myc-factor）能够调控小麦根内NRT基因的表达，但其中的机理尚不清楚。我们前期在小麦根内发现了3个受Myc-factor明显上调的NRT基因，还发现Myc-factor上调了多个独脚金内酯（SLs）生物合成相关基因，同时也激活了CSSP信号通路中的多个关键基因。据此，我们推测Myc-factor可通过诱导SLs分泌和激活CSSP信号通路而上调这3个NRT基因的表达。本项目拟通过研究（1）Myc-factor对小麦根系SLs分泌的诱导以及SLs浓度的增加对3个NRT基因表达的调控作用；（2）CSSP信号通路关键节点阻断对3个NRT基因表达的影响；（3）CSSP信号通路末端激活的GRAS转录因子对3个NRT基因表达的调控作用等3个方面来验证科学假说，这对于深入理解小麦氮吸收分子机理具有重要意义。

Nitrate transporter (NRT) genes play important roles in mediating nitrogen use efficiency (NUE) of crops. Signal moleculars produced by arbuscular mycorrhizal fungi (myc-factor) can regulate the expression of some NRT genes in wheat roots, however, mechanisms behind this regulation are still largely unknown. In our previous studies,expression of three NRT genes in wheat roots was found distinctly up-regulated by myc-factor, and myc-factor also up-regulated several genes involved in strigolactone (SLs) biosynthesis as well as many key genes involved in CSSP signal pathway. Thus, we hypothesized that myc-factor may regulate the expression of NRT genes via inducing SLs exudation and activating CSSP signal pathway. The project aimed to test three hypothesises: (1) myc-factor can induce the production of SLs of wheat roots and then up-regulate the expression of the three NRT genes; (2) the up-regulation of myc-factor on NRT genes will be disappear after inhibiting key processes of CSSP signal pathway; (3) transcriptional factors activated by CSSP signal pathway can up-regulate the expression of the three NRT genes. The project is of great importance in understanding the molecular mechanisms of wheat in nitrogen uptake.