玉米籽粒突变体基因图位克隆及功能验证

Maize(Zea mays, L.) is one of the major crops in China, therefore studing on the molecular mechanism and finding new genes to control kernel size play a crucial role in the improvement of maize yield. At present，no more than 10 genes regulating maize kernel size have been isolated and the functional mechanisms remain elusive. During the conventional breeding process, a new mutant was resulted from a natural mutation of maize kernel, the mutant have small size kernels compare to wild type maize, and the other parts of the mutant are normal. Moreover, the phenotype of this mutant is different from other small kernel mutants that have been reported.Genetic analysis indicates that the mutant phenotype is controlled by a single recessive gene. Based on these results, this project focuses on using the map-based cloning method combined with next-generation sequencing technology to find the mutant gene that control the size of kernels, reveal the function of the mutant gene and analysis the gene expression in maize. Moreover, this work will contribute to provide new markers, gene, approach and direction for the cultivation of new varieties of maize.

玉米是我国重要的粮食作物，研究调控籽粒大小的分子机理和寻找控制籽粒大小的基因，对提高玉米产量具有非同寻常的意义。目前人们只克隆到为数不多的几个调控玉米籽粒大小的基因，且相应的功能方面的研究也不够透彻。在常规育种过程中，我们获得了一个自然突变的玉米籽粒变小新突变体，该突变体除了种子明显变小外，在整个生长阶段均与其相应的野生型材料无差异，并且表型不同于以往报道的籽粒变小突变体。经过连续多代的遗传分析表明，该突变性状受细胞核中单一隐性基因控制。本研究拟利用已有的突变体材料，通过图位克隆结合新一代高通量测序的方法获得调控籽粒大小的基因，验证基因的功能并对基因的表达规律进行分析，为玉米产量的遗传改良提供重要新基因、新标记和新策略。

玉米是我国重要的粮食作物，研究调控籽粒大小的分子机理和寻找控制籽粒大小的基因，对提高玉米产量具有非同寻常的意义。目前人们只克隆到为数不多的几个调控玉米籽粒大小的基因，且相应的功能方面的研究也不够透彻。在常规育种过程中，我们获得了一个自然突变的玉米籽粒变小新突变体，该突变体除了种子明显变小外，在整个生长阶段均与其相应的野生型材料无差异。经过连续多代的遗传分析表明，该突变性状受细胞核中单一隐性基因控制。本研究利用该突变体材料，通过图位克隆结合10X Chromium技术，发现该突变是一个基因簇上两个相邻的基因之间存在大约138kb片段缺失造成的。该基因编码一类糖转运蛋白家族成员。对该基因簇进行功能验证，发现该基因定位于质膜上，在玉米籽粒淀粉合成过程起到重要作用，并且该基因参与糖信号传导与激素的响应过程。