棉花零式果枝性状候选基因功能的初步分析

发布时间：2018-08-24 12:41

【摘要】：棉花是重要的经济作物,其株型结构对产量具有较大影响。目前生产上应用的大部分陆地棉品种为无限果枝类型,果枝包含多个果节,可以无限生长;而零式果枝突变体通常表现为一节有限生长,甚至花芽直接分化于主茎叶腋处。零式果枝突变具有早熟、株型紧凑、花期集中的特点,因此,研究零式果枝突变对研究果枝发育,调控株型结构,使棉花株型紧凑,更加适于高密度种植和机采等具有重要的理论和实践意义。本研究组前期利用分子标记将海岛棉零式果枝基因定位于D7染色体上约600kb的区间内,其中包含有1个金鱼草CEN(CENTRORADIALIS)同源基因,是零式果枝基因可能的候选基因,命名为GhCEN。本研究对GhCEN利用了序列分析及拟南芥异源表达等手段,来验证GhCEN为控制零式果枝的重要基因。主要结果如下:1零式果枝性状表现为隐性遗传。通过对不同果枝类型的棉花品种的GhCEN基因的克隆、测序及序列比对发现,零式果枝材料新海18的GhCEN在P133S位存在单碱基的突变,此位点为植物CEN同源基因的保守位点,其突变可能导致GhCEN功能丧失,和单隐性基因的遗传模式相一致。2定量RT-PCR分析GhCEN基因的时空模式。结果表明,GhCEN在根中的表达量较高,茎尖中也有一定程度的富集;叶片中GhCEN基因mRNA丰度极低,并不随叶龄发生变化。不同光周期处理结果表明:长日照处理下(16h),根和叶片都是在光培养条件下进行GhCEN的合成,并呈现昼夜节律变化;短日照处理下(8h),GhCEN基因在叶片的表达量显著高于根中表达量。3转拟南芥功能验证。采用35S启动子在拟南芥中过表达GhCEN基因和突变基因cen都可以导致拟南芥的提早开花。棉花中零式果枝材料表现为早花,因此GhCEN基因在拟南芥和棉花中可能受到不同的遗传调控。
[Abstract]:Cotton is an important cash crop, its plant type structure has great influence on yield. At present, most upland cotton varieties used in production are infinite fruit branch type, the fruit branch contains more than one fruit node and can grow infinitely, while the zero-type fruit branch mutant usually shows a limited growth, even the flower bud differentiates directly in the main stem and leaf axils. The zero-type branch mutation has the characteristics of early maturity, compact plant type and concentrated flowering period. Therefore, the study of zero-type branch mutation on the study of fruit branch development, regulation of plant type structure, making cotton plant type compact, More suitable for high density planting and mechanical harvesting has important theoretical and practical significance. This study used molecular markers to locate the zero-type fruit-branch gene in the region of 600kb on chromosome D7, which contained a CEN (CENTRORADIALIS) homologous gene, which was a possible candidate gene for zero-type fruit-branch gene, named GhCEN.. In this study, sequence analysis and heterologous expression of Arabidopsis thaliana were used to identify GhCEN as an important gene to control zero-type fruit branch. The main results were as follows: 1. By cloning, sequencing and sequence alignment of GhCEN gene of cotton varieties with different fruit-branch types, it was found that the GhCEN of the zero-type fruit branch material Xinhai 18 had a single base mutation at the P133s site, which was the conserved site of the plant CEN homologous gene. The mutation may lead to the loss of GhCEN function, which is consistent with the genetic pattern of single recessive gene. 2. Quantitative RT-PCR is used to analyze the temporal and spatial pattern of GhCEN gene. The results showed that the expression of GhCEN was higher in the root and the stem tip was also enriched to some extent, and the mRNA abundance of the GhCEN gene in the leaves was very low and did not change with the leaf age. The results of different photoperiod treatments showed that under long sunlight (16h), root and leaf were synthesized under light culture condition, and the circadian rhythm was observed. (8 h) GhCEN gene expression in leaves was significantly higher than that in roots (3. 3%) and the function of Arabidopsis thaliana was verified. Overexpression of GhCEN gene and mutant gene cen in Arabidopsis thaliana by 35s promoter can lead to early flowering of Arabidopsis thaliana. The zero-type fruit-branch materials in cotton showed early flowering, so the GhCEN gene may be controlled by different genetic regulation in Arabidopsis thaliana and cotton.
【学位授予单位】：塔里木大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S562

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