磷酸盐转运蛋白1（Phosphate transporter1，PHT1）家族基因参与植物体内磷代谢、镉胁迫响应和丛枝菌根（Arbuscular mycorrhiza，AM）真菌共生间的互作网络，然而PHT1家族基因响应镉胁迫下AM真菌共生的分子机制尚不明晰。申请人前期研究表明先锋树种构树（Broussonetia papyrifera）具有较强的耐镉性，AM真菌提高了构树的耐镉性和磷吸收，同时调控PHT1家族基因响应镉胁迫的转录模式。在此基础上，本项目拟通过解析镉污染的多重胁迫和CRISPR-Cas9基因编辑等手段，明确镉胁迫对构树PHT1家族基因调控的途径，探明AM真菌调控构树PHT1家族关键基因应对镉胁迫的机制，明确构树中受AM真菌调控的PHT1家族关键基因在影响构树菌根耐镉性和镉积累方面的作用。本项目的开展将以磷代谢与镉毒害互作的视角为菌根化林木耐受镉污染提供理论依据。

The PHosphate Transporter1 (PHT1) gene family is involved in the interaction network between phosphorus metabolism, cadmium (Cd) stress response, and arbuscular mycorrhizal (AM) fungal symbiosis in plants, however, the molecular mechanisms of PHT1 gene family in response to AM fungal symbiosis under Cd stress remains unclear. Our previous study indicated that Broussonetia papyrifera, a pioneer tree species, had a strong resistance to cadmium (Cd) toxicity; Arbuscular mycorrhizal (AM) fungi improved the resistance of B. papyrifera to Cd toxicity, enhanced the phosphorus uptake of B. papyrifera, and regulated the transcriptional pattern of PHT1 gene family in response to Cd stress. On this basis, we will analyze multiple stresses from Cd pollution and use the CRISPR-Cas9 gene-editing technology, to clarify the specific way of Cd stress regulating PHT1 genes, to explore the mechanism of AM fungi regulating critical PHT1 genes of B. papyrifera in response to Cd stress, and to confirm the role of critical PHT1 genes regulated by AM fungi in alleviating Cd stress of B. papyrifera with mycorrhizal symbiosis. The implementation of this project will provide a theoretical basis for the tolerance of mycorrhizal trees to Cd pollution with a perspective on interaction between phosphorus metabolism and Cd toxicity.