谷子穗部突变体sidts1的鉴定及候选基因功能分析

发布时间：2018-05-15 16:36

本文选题：谷子 + 花发育　；参考：《山西大学》2017年硕士论文

【摘要】：谷子,其种子脱皮后即为人们俗称的“小米”,是我国重要的粮食作物之一,由于其含有很高的营养价值,越来越受到人们的关注。同时,由于谷子为二倍体自花授粉作物,基因组较小(约515M),与水稻基因组具有较高的共线性,正逐步发展为一种模式作物。此外,谷子还是C4植物,对谷子研究的不断深入对于光合作用的研究具有重要的意义。花器官的发育对禾本科粮食作物的产量和品质都有着直接影响,对穗部研究,尤其是花序发育的研究,不仅对了解植物的遗传和生殖具有重要意义,对于提高粮食的产量及质量也具有指导意义。本研究利用化学诱变剂甲基磺酸乙酯(ethyl methylsulfonate,EMS)诱变谷子Yu1(豫谷1号)品种,筛选得到一个可以稳定遗传的穗部突变体sidts1(degenerated top spike)。与野生型Yu1相比,该突变体突变特征主要表现在穗部变短、变细、顶部变尖;穗下部码粒较紧实,由下往上花器官数目逐渐减少导致结实率降低,穗顶部几乎不结实,但结实的种子变大;同时在穗上部谷码的部分各级分支尖端呈现出明显红色,表现出红尖穗且穗上部小花退化。对穗部锌、铁金属含量测定发现突变体sidts1穗部锌和铁元素的含量均比野生型Yu1中的含量显著升高。利用突变体sidts1与SSR41杂交构建的F_2定位群体进行基因定位,经过χ~2检测正常株与突变株符合3:1分离比,证明该突变性状为细胞核隐性单基因控制。采用BSA(Bulked Segregation Analysis)法,将突变基因定位在6号染色体一端0-137Kb的区间,结合高通量测序分析结果最终锁定候选基因,命名为SiDTS1。该基因编码具有7个跨膜结构域的蛋白,仅含有一个ZIP(Zinc/iron permease)蛋白结构域,与金属元素锌、铁等的摄取、转运相关。表达量分析显示SiDTS1基因在孕穗期根、茎、叶、穗都有表达,在穗中的表达量最高。通过构建SiDTS1-GFP融合表达载体,发现该基因定位在液泡膜。对谷子ZIP蛋白家族成员挖掘及qRT-PCR分析,发现在谷子中还有16个ZIP蛋白家族基因,这些基因具有表达特异性。本研究以sidts1红尖穗且穗上部小花退化突变体为研究材料,对锌、铁微量金属营养元素含量对谷子花器官发育的影响进行了初步探究,为以后禾本科花发育的相关研究提供了方向。
[Abstract]:Millet, which is commonly known as millet after peeling, is one of the most important food crops in China. Because of its high nutritional value, millet has attracted more and more attention. At the same time, because millet is a diploid self-pollinated crop, the genome is smaller (about 515Mg), which has a high collinearity with the rice genome, and is gradually developing into a model crop. In addition, millet is also a C4 plant. The further study of millet is of great significance to the study of photosynthesis. The development of floral organs has a direct effect on the yield and quality of gramineous grain crops. The study of panicle, especially the development of inflorescence, is of great significance not only in understanding the heredity and reproduction of plants, but also in the development of inflorescence. For improving grain production and quality also has a guiding significance. In this study, a mutants of Yu-1 (Yugu 1) were obtained by mutagenesis of ethyl methyl sulfonate (EMS1), a stable genetic mutant sidts1(degenerated top spikee, which was used to mutate millet Yu1 (Yugu 1) by using the chemical mutagen ethyl methyl sulfonate (EMS1). Compared with wild-type Yu1, the mutant was characterized by shorter panicle, thinner panicle and sharper top, and tighter grains at the lower ear, which resulted in a decrease in the number of flower organs from the bottom to the top leading to a decrease in the seed setting rate, and almost no seed setting at the top of the ear. At the same time, the tip of some branches of grain code in the upper ear showed obvious red, showing red spikelet and degeneracy of floret in the upper ear. It was found that the contents of Zn and Fe in spike of mutant sidts1 were significantly higher than those in wild type Yu1. The FSC2 locational population constructed by sidts1 and SSR41 hybridization was used to localize the gene. 蠂 ~ 2 was used to detect the 3:1 segregation ratio between the normal strain and the mutant strain. It was proved that the mutant trait was controlled by a single nuclear recessive gene. Using BSA(Bulked Segregation analysis, the mutant gene was located in the region of 0-137Kb at one end of chromosome 6, and the candidate gene was finally locked in combination with high-throughput sequencing analysis, named SiDTS1. The gene encodes seven transmembrane domain proteins containing only one ZIP(Zinc/iron permeaseprotein domain, which is related to the uptake and transport of zinc and iron. Expression analysis showed that SiDTS1 gene was expressed in root, stem, leaf and ear at booting stage, and the highest expression was found in ear. The SiDTS1-GFP fusion expression vector was constructed and the gene was located in the vacuolar membrane. The ZIP protein family members of millet were excavated and qRT-PCR analysis showed that there were also 16 ZIP family genes in millet, which were expressed specifically. In this study, the effects of the contents of zinc and iron micronutrients on the development of flower organs in millet were studied with sidts1 red spikelet and flower degeneration mutants at the top of spike. It provides a direction for the research on the flower development of Gramineae in the future.
【学位授予单位】：山西大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S515

【参考文献】