玉米叶片夹角是影响产量的重要农艺性状，直立的叶片可显著提高光合效率、增加种植密度，进而增加产量。课题组利用3套F2:3家系对叶夹角进行QTL定位，对检测到3个主效QTL qLA1、qLA2、qLA4构建近等基因系并进行精细定位。已克隆到qLA1的候选基因，并通过关联分析初步验证其功能。在此基础上，本研究拟通过图位克隆技术克隆qLA2和qLA4的候选基因，利用遗传转化和关联分析方法验证其功能；利用蛋白质组学技术研究3个候选基因的表达规律，发掘与其互作的蛋白质和相应的转录因子，构建蛋白质互作网络，分析叶夹角形成的信号转导途径；利用转录组测序技术鉴定具有差异表达的新基因，解析3个候选基因与新鉴定基因的关系；从细胞水平上分析叶夹角形成的作用机制。本项目实施不仅对玉米耐密高产育种及分子标记辅助选择提供理论依据，而且对解析叶夹角形成过程中关键基因及蛋白信号在互作网络中调控的生物功能提供参考。

Leaf angle is one of important agronomic traits affecting the yield in maize. Upright leaves can significantly improve photosynthetic efficiency and increase planting density, and then increase maize yield. The quantitative trait loci (QTL) for leaf angle were mapped using three sets of F2:3 families in our previous study. Three major QTL (qLA1, qLA2, qLA4) were detected and the corresponding near-isogenic lines were constructed. The three QTL had been fine mapping. At present, the candidate gene in the qLA1 region had been cloned and its function was validated by association analysis. On this basis, the researches aim to clone the candidate genes of qLA2 and qLA4 regions by map-based cloning. the functions will validated by association analysis and genetic transformation. The expression pattern, interaction proteins and transcription factors of three candidate genes will be studied by proteomic techniques and the protein interaction network will be constructed, which will suggest signal transduction of leaf angle formation. Differentially expressed genes will be identified and the relationships between the three candidate genes and new identified genes will analyzed by the transcriptome sequencing. The action mechanisms of leaf angle formation will identified from the cellular level. The implementation of this project will provide a theoretical basis not only for the corn resistant to the dense high-yield breeding and molecular marker-assisted selection but also reference for biological functions of key genes and protein in the signaling interaction network during the formation of leaf angle.