为挖掘玉米CMS-C败育相关基因(ORFs),以不育系K932S和K169S、保持系K169和恢复系K932R为材料,通过二代测序技术对线粒体基因组序列进行比较分析。结果表明,不育胞质K932S、K169S和K932R线粒体基因组大小分别为739676bp 、739723bp和739765bp ,正常胞质K169为 569617bp；注释到蛋白编码基因33个,tRNA基因15-16个和rRNA基因3-4个。大于100bp重复序列在不育胞质和正常胞质基因组中分别为19个和10个,小于100bp重复序列差异不大；同源片段在3个不育胞质基因组中排列顺序一致,共线性达99%以上,而正常胞质中3个片段反转,排列顺序也发生了重大改变,相似度为95%。4个基因组中发现ORFs145-151个,其中K169S与K169间差异基因(ORFs)高达13个,而与K932S或K932R间差异仅1个,K169S特有ORFs 8个。可见,玉米CMS-C线粒体基因组明显大于正常胞质,不同核背景对基因组大小影响小；基因组在组成上极为相似,但在不育和正常胞质间结构上存在较大差异,大于100bp重复序列是造成基因组大小差异的主要原因。筛选出orf429(atp6-c)、orf104-s、orf410、orf349和orf246等ORFs 5个,可能与CMS-C败育相关,为解析玉米CMS-C败育机理提供了基因组信息。

In order to dig up genes (ORFs) related to CMS-C sterility in maize, The sequences of mitochondrial genome of four materials, sterile line K932S and K169S, maintainer line K169 and restorer line K932R, were comparatively analyzed by using next-generation sequencing technology. The results showed that the mitochondrial genome length of sterile cytoplasm K932S, K169S and K932R were 739676bp, 739723bp and 739765bp, respectively; and that of normal cytoplasm K169 was 569617bp; 33 protein coding genes ,15-16 tRNA genes and 3-4 rRNA genes were annotated. There were 19 and 10 repetitive sequences longer than 100bp in the sterile cytoplasmic and normal cytoplasmic genomes, respectively, and repetitive sequences shorter than 100bp presented little differences; Among the three sterile cytoplasmic genomes , the homologous fragments are arranged in the same order, with a collinearity of 99 %, however, three reversed fragments were found in the normal cytoplasm, and the arrangement order also changed, with a similarity of 95%. Among the four genomes, 145-151 ORFs were found, there were 13 differential genes (ORFs) between K169S and K169, but only 1 of that was extracted between K932S and K932R, 8 unique ORFs was discovered in K169S mitochondrial genome. In summary, the mitochondrial genome size of maize CMS-C is obviously larger than that of the normal cytoplasm,

四川省科技支撑计划项目(2016NYZ0006)