小麦发育相关基因TaMOR和TaPARG的克隆与功能分析

发布时间：2018-03-03 01:07

本文选题：小麦　切入点：TaMOR　出处：《中国农业科学院》2016年博士论文　论文类型：学位论文

【摘要】：小麦(Triticum aestivum L.)是人类的主要粮食作物,但是小麦生产受到干旱等逆境条件的严重制约。为了满足世界人口不断增长对粮食的需求,育种家通过遗传改良培育抗逆高效新品种以获得更高的产量。小麦的根系结构和株型直接影响着产量,揭示根系和株型发育的遗传基础,发掘并利用优异基因资源对于小麦的遗传改良具有重要意义。植物AS2/LOB(ASYMMETRIC LEAVES2/LATERAL ORGAN BOUNDARIES)和AP2/EREBP(APETALA2/ETHYLENE-RESPONSIVE ELEMENT BINDING PROTEINS)是调控生长发育的两个重要基因家族。本研究以小麦品种旱选10号为试验材料,克隆了小麦Ta MOR(MORE ROOT)和Ta PARG(PLANT ARCHITECTURE-RELATED GENE)基因,分别属于LOB和AP2/EREBP基因家族。通过分析基因的序列特征及功能,明确了Ta MOR和Ta PARG在生长发育中的重要作用。主要研究结果如下:1.过表达小麦基因Ta MOR能改良水稻的根系和产量。Ta MOR属于LOB基因家族,在小麦及其近缘植物中高度保守。小麦中三个复等位基因Ta MOR-A、Ta MOR-B和Ta MOR-D序列相似性达96.9%,编码的氨基酸序列相似度高达97.12%。组织表达分析表明Ta MOR在不定根和侧根起始部位的表达量显著高于其它组织,并且表达模式与根系的形成时间吻合,表明Ta MOR参与小麦根系的起始。外源生长素(IAA)能诱导Ta MOR表达,并且不需要体内蛋白的重新合成。体内和体外的试验都证明Ta MOR能与Ta MRRP(Ta MOR-RELATED PROTEIN)发生互作。过表达Ta MOR-D的转基因拟南芥具有更多的侧根,过表达Ta MOR-D的转基因水稻性状发生显著变化:冠状根数目增多,主穗增长,主穗一次枝梗数和单株穗粒数增加,单株产量提高。总之,过表达Ta MOR-D的拟南芥和水稻具有更发达的根系,并且转基因水稻单株产量显著提高。2.小麦转录因子Ta PARG是新的AP2/EREBP类多效基因,调节株型和产量相关性状发育。在小麦中检测到Ta PARG的两个拷贝Ta PARG-2A和Ta PARG-2D,其编码的氨基酸序列相似性高达97.67%,尤其是功能结构域的序列完全相同。Ta PARG-2A定位于染色体2A上的Xwmc63和Xgwm372标记之间,Ta PARG-2D定位于染色体2D上。Ta PARG蛋白定位于细胞核。通过Ta PARG组织表达模式分析,单倍型与性状的关联分析,以及过表达转基因水稻表型分析,结果都表明Ta PARG在生长发育过程中发挥多种功能,包括调控株高和分蘖数等株型相关性状和千粒重等产量相关性状。在小麦中检测到Ta PARG-2A的三种单倍型,其中Hap-2A-2和Hap-2A-3是降低株高和分蘖数、提高千粒重的优异单倍型。这两种优异单倍型的形成可能是由于单个氨基酸的改变(His/Tyr)。在我国小麦育种的历史进程中,两种优异单倍型受到了较强的正向选择。研究结果表明,Ta PARG调节小麦株型和产量相关性状发育,优异单倍型及其分子标记在小麦株型和产量改良中具有重要的应用价值。综合以上结果,小麦Ta MOR和Ta PARG分别参与根系、株型和产量性状发育的调控,为小麦高产高效的遗传改良提供了理论依据和技术支撑。
[Abstract]:Wheat (Triticum aestivum L.) is the main food crops in the world, but seriously restrict wheat production under drought stress. In order to meet the world's growing demand for food and breeding by genetic breeding of resistant varieties, in order to obtain a higher yield. The root structure and directly affects the yield of wheat and reveal the genetic basis of root and plant development, exploitation and utilization of excellent gene resources have important meaning for genetic improvement of wheat plants. AS2/LOB (ASYMMETRIC LEAVES2/LATERAL ORGAN BOUNDARIES) and AP2/ EREBP (APETALA2/ETHYLENE-RESPONSIVE ELEMENT BINDING PROTEINS) is the two important gene family in the regulation of the growth and development of wheat varieties with drought. This study selected No. 10 as test materials, cloning of wheat Ta MOR (MORE ROOT) and Ta PARG (PLANT ARCHITECTURE-RELATED GENE) gene, belonging to LO B and AP2/EREBP gene family. The sequence characteristics and functional analysis of genes, clear the important role of Ta MOR and Ta PARG in growth and development. The main results are as follows: 1. the over expression of Ta gene in wheat MOR to improve rice roots and yield of.Ta MOR belongs to LOB gene family in wheat and its relative plant height conservative. Wheat three alleles of Ta MOR-A, Ta MOR-B and 96.9% similarity of Ta MOR-D sequence, encoding the amino acid sequence similarity is as high as 97.12%. tissue expression analysis showed that the Ta expression of MOR in the amount of adventitious roots and lateral root initiation sites was significantly higher than that in other tissues, and the expression pattern and the formation time of anastomosis of root system. That Ta MOR is involved in root initiation. Exogenous auxin (IAA) can induce Ta MOR expression, and does not need to re synthesize protein. Experiments in vivo and in vitro have proved that Ta MOR and Ta MRRP (Ta MOR- RELATED PROTEIN) interacted. Over expression of transgenic Arabidopsis Ta MOR-D has more lateral roots, over expression of Ta MOR-D transgenic rice traits changed significantly: crown root number, main panicle growth, main panicle number of primary branches per plant and grains per panicle increased, yield per plant increased. In short, over expression of Ta MOR-D the Arabidopsis and rice has more developed roots, and transgenic rice yield significantly increased wheat.2. transcription factor Ta PARG is a new AP2/EREBP class of gene regulation, plant type and Yield Related Traits and development. To detect two copies of Ta PARG-2A and Ta PARG-2D Ta PARG in wheat, similar to the amino acid sequence of encoding up to 97.67%, especially between Xwmc63 and Xgwm372 marker sequences of the functional domain identical to the.Ta PARG-2A located on chromosome 2A, Ta PARG-2D.Ta PARG is located on chromosome 2D in egg white Through the analysis of the Ta PARG model of the nucleus. The expression, correlation analysis and haplotype traits, and expression analysis of transgenic rice phenotype, results show that Ta PARG play multiple functions in the process of growth and development, including the regulation of traits related to plant height and tiller number and plant type traits and 1000 grain weight to yield three Ta haplotypes. The detection of PARG-2A in wheat, Hap-2A-2 and Hap-2A-3 decreased plant height and tiller number, 1000 grain weight increased the excellent haplotypes. The formation of these two excellent haplotypes may be due to a single amino acid change (His/Tyr). In the historical process of wheat breeding in China, two have strong positive selection of excellent haplotypes. The results show that the Ta PARG regulation of wheat plant type and Yield Related Traits and development, excellent haplotype and molecular marker has important application value in wheat plant type and yield improvement In conclusion, wheat Ta MOR and Ta PARG were involved in the regulation of root, plant type and yield traits, providing a theoretical basis and technical support for high yield and high efficiency genetic improvement of wheat.

【学位授予单位】：中国农业科学院
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S512.1;Q943.2

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