过量表达ML基因培育水稻高产新品系

发布时间：2018-02-05 05:41

本文关键词： 水稻产量因子维管束光合作用转醛醇酶基因　出处：《扬州大学》2016年硕士论文　论文类型：学位论文

【摘要】：水稻是我国最重要的粮食作物之一,提高水稻产量对于保障我国的粮食安全具有举足轻重的作用。水稻产量主要有三大因子控制,分别为单株穗数、每穗粒数和千粒重,均是由多基因控制的复杂性状。我国当前水稻产量潜力的提高急需构建更高效的育种技术体系,而基于产量形成相关基因及其调控网络解析的分子育种已经成为突破产量育种瓶颈的有效途径。而开展分子育种的首要工作就是定位、克隆相关农艺性状的基因,以及这些基因及其复等基因之间的效应和互作关系。本研究以一个编码转醛醇酶的TAL(transaldolase-like)基因为研究对象,通过构建高产品种武运粳7号背景下的RNAi和过量表达转基因株系,结合组织形态学和生理学的研究手段,初步解析了 TAL基因调控水稻产量形成的遗传生理学基础。主要研究结果如下:1、亚细胞定位分析表明,TAL蛋白呈现普遍存在在分布的特点,同时存在于细胞膜、细胞质和细胞核上。2、TAL基因具有多效性,影响水稻植株生长发育的多个方面。从苗期到成熟期,TAL基因过量表达株系均表现出很强的生长势,而将其敲除,植株则表现弱小。3、TAL基因参与调控水稻叶片和茎秆维管束的发育过程。过量表达该基因可以增加剑叶小维管束的数目,但对大维管束数目没有显著影响,同时可以增加茎秆大、小维管束数目。而在RNAi株系中,剑叶和茎秆中大、小维管束的数目均显著下降。4、过量表达株系中,植株叶片的蒸腾速率、净光合速率和气孔导度均比对照有显著升高,而细胞间隙CO2浓度则低于对照;而在RNAi株系中则表现相反的结果。说明,过量表达TAL基因能显著提高水稻的光合作用。5、TAL基因影响多个产量性状,过量表达该基因可以使千粒重增加7.1～7.9%,使每穗粒数增加13.2～15.3%,最终使单株籽粒产量增加了 18.5～20.7%,群体产量分别增加了10.6～12.4%。相反,将该基因敲除,则造成千粒重和每穗粒数显著减少,产量也相应降低。因此该基因具有潜在的育种价值,是利用基因工程策略增加水稻产量的重要靶点。
[Abstract]:Rice is one of the most important food crops in China, and increasing rice yield plays an important role in ensuring food security in China. Rice yield is mainly controlled by three factors, which are the number of panicles per plant. The number of grains per panicle and the weight of 1000 grains per panicle are complex traits controlled by polygenes. It is urgent to construct a more efficient breeding technique system for the improvement of rice yield potential in China at present. Molecular breeding based on the analysis of genes related to yield formation and its regulatory network has become an effective way to break through the bottleneck of yield breeding. Cloning of genes related to agronomic traits. And the effect and interaction between these genes and their complex genes. A transaldolase-like gene encoding transaldolase was studied in this study. RNAi and overexpression transgenic lines were constructed under the background of Wuyunjing 7, and combined with histomorphology and physiological research methods. The genetic and physiological basis of rice yield formation regulated by TAL gene was preliminarily analyzed. The main results were as follows: 1. The subcellular localization analysis showed that the TAL protein was widely distributed. At the same time, it exists in cell membrane, cytoplasm and nucleus. It has multiple effects on the growth and development of rice plants, from seedling stage to mature stage. The overexpression lines of TAL gene showed strong growth potential, but knockout showed that the plants were weak. 3. TAL gene is involved in regulating the development of vascular bundles in rice leaves and stems. Overexpression of the gene can increase the number of small vascular bundles in flag leaves, but has no significant effect on the number of large vascular bundles. At the same time, the number of large and small vascular bundles was increased, while in RNAi lines, the number of small vascular bundles and flag leaves in stem decreased significantly by .4. the transpiration rate of leaves in RNAi lines was overexpressed. The net photosynthetic rate and stomatal conductance were significantly higher than that of the control, while the intercellular CO2 concentration was lower than that of the control. The results showed that the over-expression of TAL gene could significantly improve the photosynthesis of rice. 5Tal gene affected many yield traits. Overexpression of the gene could increase the 1000-grain weight by 7.1%, increase the number of grains per panicle by 13.2% and increase the grain yield by 18.5%. Population yield increased 10.6% 12.4g respectively. On the contrary, knockout of the gene resulted in a significant decrease in 1000-grain weight and grain number per panicle, as well as a corresponding decrease in yield. Therefore, the gene has potential breeding value. It is an important target for increasing rice yield by genetic engineering strategy.
【学位授予单位】：扬州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S511

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