干旱胁迫下AMF调控玉米CBL-CIPK钙离子信号通路的分子机理

Arbuscular mycorrhiza fungi (AMF) improve the absorption of water and nutrients in the host plant and promotes plant drought tolerance, which have become one of the highlights of mycorrhiza field in recent years, and have great practical significance to improve the drought resistance of grain crops in particular. This project is based on the study of AMF to promote the drought tolerance of maize in the early stage of the project. Under drought and normal water conditions, maize (inoculated and not inoculated with AMF) transcriptomes are analyzed by high throughput Solexa sequencing, and bioinformatics are used to screen maize CBL-CIPK gene regulated by AMF under drought stress, and structure analysis and function prediction of the gene encoding protein are also explored. Using qRT-PCR technology, whether AMF regulates the transmission and metabolic key genes of the upstream ABA signal and the expression of the downstream ZmK1 potassium channel gene are verified. Combined with related physiological indexes, molecular mechanisms of AMF regulating CBL-CIPK-ZmK1 and CBL-CIPK-ABA signaling pathway in maize under drought stress are revealed. The molecular mechanisms of AMF regulating CBL-CIPK calcium signaling pathway in maize are finally revealed under drought stress. This study has important theoretical and practical significance to improve the drought resistance of grain crops.

丛枝菌根真菌（AMF）改善宿主植物水分和养分吸收、促进生长、提高植物耐旱机理已成为近年来菌根研究的重点，特别对提高粮食作物抗旱性具有重大现实意义。本项目在课题组前期AMF促进玉米耐旱生理指标研究的基础上，在干旱和正常水分条件下，对接种和不接种AMF的玉米转录组进行高通量Solexa测序分析，并利用生物信息学手段筛选出干旱胁迫下受AMF调控显著的玉米CBL-CIPK基因，并对其基因编码蛋白进行结构分析和功能预测。利用qRT-PCR技术验证干旱胁迫下，AMF是否通过调控上游ABA信号传导和代谢关键基因以及下游ZmK1钾离子通道基因表达，结合相关生理指标检测，揭示干旱胁迫条件下AMF调控玉米CBL-CIPK-ZmK1和CBL-CIPK-ABA信号通路的分子机理。最终揭示干旱胁迫下AMF调控玉米CBL-CIPK钙离子信号通路的分子机理，该研究对提高粮食作物的抗旱能力具有重要的理论与实践意义。

干旱胁迫下，丛枝菌根真菌（AMF）改善玉米耐旱性，但AMF调控玉米钙离子信号通路机制尚缺乏报道。本项目首先在干旱和正常水分条件下，对接种和不接种AMF的玉米转录组进行高通量转录组分析，并通过qRT-PCR技术，筛选和验证出了干旱胁迫条件下受AMF显著调控的CBL、CIPK家族基因；同时挖掘出受AMF显著调控CBL-CIPK钙离子信号通路上游ABA信号传导和代谢关键基因以及下游ZmK1钾离子通道基因表达，揭示干旱胁迫条件下AMF可能调控了玉米CBL-CIPK-ZmK1和CBL-CIPK-ABA信号通路；通过生物信息学手段分析和预测了这些CBL、CIPK家族基因及其表达蛋白的结构及其生物学功能，揭示了受AMF调控的CBL-CIPK钙离子信号通路的生物学功能；对CBL、CIPK基因重组大肠杆菌的抗旱性检测，发现zmCIPK1、zmCBL9基因重组大肠杆菌与野生型相比显著提高了对山梨醇的干旱胁迫能力；盆栽试验也表明：接种AMF能够显著降低玉米根和叶中ABA水平，改变玉米根系和叶片亚细胞中钙的含量和分布，促进了玉米在干旱胁迫条件下Ca2+离子的稳定性，同时提高玉米的光合性能，这些与AMF调控CBL-CIPK钙离子信号通路存在一定相关性。该研究揭示干旱胁迫条件下AMF调控玉米CBL-CIPK信号通路的分子机理。