甘蔗果糖激酶基因家族基因组演化及功能研究

发布时间：2019-05-05 10:06

【摘要】：作为全球最重要的高糖农作物,甘蔗由于其复杂的遗传背景,至今尚无甘蔗全基因组序列,而对蔗糖代谢的基因组学研究处于起步阶段。果糖激酶作为糖代谢中一个重要的激酶,对其在甘蔗基因组学和功能研究上均为空白。本研究应用比较基因组学手段结合项目组的酵母人工染色体文库,将根据甘蔗的近缘物种高粱的果糖激酶基因来对甘蔗果糖激酶基因家族成员进行鉴定,在甘蔗中鉴定出果糖激酶基因家族7个成员,命名为ScFRK1-ScFRKScFRK7,并对这七个成员进行单倍型基因结构注释和单倍型Ka/Ks分析。应用甘蔗近缘属物种高粱、玉米以及单子叶模式植物水稻,双子叶代表性植物西红柿、拟南芥、葡萄和马铃薯共8个物种的果糖激酶基因家族共71个果糖激酶基因构建一个系统演化图和结构注释,研究甘蔗与植物果糖激酶基因家族的系统演化,结果显示甘蔗果糖激酶基因家族在单双子叶植物分化之前已存在,属于比较古老的基因家族。果糖激酶基因家族经过三次的基因组复制事件后形成7个家族成员,其中最古老的基因是ScFRK6和ScFRK7,其次是ScFRK4,最后ScFRK1、ScFRK2、ScFRK3和ScFRK5。分析甘蔗果糖激酶在四个甘蔗品种的不同生长周期以及在不同激素处理下,果糖激酶基因家族表达量的差异,结果显示ScFRK1和ScFRK5是主效基因,在不同生长周期和不同激素处里下,甘蔗果糖激酶的表达模式不一样。其中ScFRK1表达量最高,而ScFRK5次之,SsFRK7是这个基因家族中最低的表达成员,这说明甘蔗果糖激酶家族基因SsFRK1可能是主效基因,相比其他激素胁迫,ScFRK4在GA胁迫下表达量增加明显,推测ScFRK4在甘蔗发芽、分蘖过程中起比较重要的作用。借助模式植物拟南芥,将果糖激酶基因导入整合到拟南芥突变体和野生型中,观察拟南芥表型的变化,因为果糖激酶对植物维管组织和糖代谢有比较重要的作用,因此主要看根茎长度的变化,发现果糖激酶ScFRK1和ScFRK5对拟南芥根茎的生长分别有抑制和促进的作用,具体的作用机制则需要后续进一步的研究探讨。
[Abstract]:As the most important high sugar crop in the world, sugarcane has no whole genome sequence due to its complicated genetic background, but the genomics research on sucrose metabolism is still in its infancy. Fructose kinase, as an important kinase in sugar metabolism, is blank in genomics and function research of sugarcane. In this study, combining comparative genomics with yeast artificial chromosome library, members of sugarcane fructose kinase gene family were identified according to the fructose kinase gene of sorghum, a closely related species of sugarcane. Seven members of the fructose kinase gene family were identified in sugarcane and named ScFRK1-ScFRKScFRK7,. Haplotype gene structure annotation and haplotype Ka/Ks analysis were performed on the seven members. Application of sugarcane related species sorghum, maize and monocotyledon model plant rice, dicotyledon representative plant tomato, Arabidopsis thaliana, A phylogenetic map and structural annotation of 71 fructose kinase genes from eight species of grape and potato were constructed to study the phylogenetic evolution of fructose kinase gene family in sugarcane and plants. The results showed that the fructose kinase gene family of sugarcane existed before the differentiation of dicotyledonous plants and belonged to the older gene family. The fructokinase gene family formed seven family members after three genomes replication events, the oldest of which was ScFRK6 and ScFRK7, followed by ScFRK4, ScFRK1,ScFRK2,ScFRK3 and ScFRK5.. The differences of the expression of fructose kinase gene family in four sugarcane varieties were analyzed. The results showed that ScFRK1 and ScFRK5 were the major genes in different growth cycles and different hormone treatments, and the results showed that fructose kinase gene was the main gene in different growth cycles and different hormone locations, and the expression of fructose kinase gene family was different in different growth cycles and different hormone treatments. The expression pattern of fructose kinase in sugarcane is different. The expression of ScFRK1 was the highest, followed by ScFRK5, and SsFRK7 was the lowest expressed member of this gene family. This indicated that SsFRK1 gene of sugarcane fructose kinase family might be the major gene. Compared with other hormone stress, the expression level of ScFRK4 under GA stress was significantly increased. It is suggested that ScFRK4 plays an important role in sugarcane germination and tillering. With the help of the model plant Arabidopsis thaliana, the fructose kinase gene was introduced into Arabidopsis mutants and wild type, and the phenotypic changes of Arabidopsis thaliana were observed because of the important role of fructose kinase in vascular tissue and glucose metabolism in plants. Therefore, it was found that fructose kinase ScFRK1 and ScFRK5 could inhibit and promote the growth of Arabidopsis thaliana rhizome respectively, and the specific mechanism needed to be further studied.
【学位授予单位】：福建师范大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S566.1;Q943.2

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