Genome-Wide Analysis of MuDR-Related Transposable Elements Insertion Population in Maize

Insertional mutagenesis has now been widely used to knockout genes for functional genomics. The maize Mutator transposons hold an advantage of high activity to construct large mutant libraries. In this study, a MuDR line was used to cross with an elite Chinese maize inbred line Z31. A total of 1000 M1 individuals were planted and self-pollinated to generate their M2 families. Experiments were conducted to investigate the insertion specificity of MuDR related transposable elements. Six hundred and ninety-five MuDR inserted flanking sequences were isolated with a modified MuTAIL-PCR method and analyzed with bioinformatics. Three hundred and seventy-four non-redundant insertion sites were identified and 298 of them were mapped to a single locus on the integrated maize map. The results revealed some prominent features of the MuDR-related insertions of maize: random distribution across the 10 chromosomes, preferential insertion into genic sequence and favoring some classes of functional genes.

摘要采用农杆菌介导法将红色荧光蛋白基因DsRed转入轮枝镰孢Fv-1菌株, 利用荧光显微镜观察轮枝镰孢在玉米自交系B73根部定殖和生长的规律。土壤中的轮枝镰孢首先侵染玉米的须根等组织, 并在其中大量增殖, 随后沿主根向上侵染, 以菌丝的形式扩展到地上组织。有些孢子附着在根表面的纹理中, 萌发形成菌丝而扩展; 有的则向内侵染附着的细胞, 然后再继续向周边侵染。由根内部向上侵染的菌丝多沿着细胞间隙上行, 有些也会穿行在不同细胞之间。分析接种不同时间轮枝镰孢在玉米根和茎基部组织形成的单菌落数量(CFU)发现, 轮枝镰孢在根部的CFU值随时间逐渐减小, 而茎基部的CFU值则呈逐渐增大的趋势。这说明土壤中的轮枝镰孢能够通过根系侵染途径危害地上部组织。本研究的结果为进一步探明轮枝镰孢和玉米之间的互作关系, 以及其他土传真菌与植物之间的互作提供了有益的参考。