TaNF-Y1和TaNF-Y2转基因小麦的抗旱性鉴定

发布时间：2018-06-16 00:41

本文选题：小麦 + 核转录因子　；参考：《西北农林科技大学》2017年硕士论文

【摘要】：小麦是我国主要的粮食作物之一,其产量的高低直接关系到粮食安全。小麦生产时常受到干旱的影响。发掘抗旱相关基因并通过分子育种的方法培育抗旱新品种至关重要。已有研究表明,转录因子基因是重要的抗旱相关候选基因源。前期的抗逆基因挖掘研究中,本实验室从小麦干旱转录谱中筛选到两个NF-Y类核转录因子(nuclear transcription factor)基因,TaNF-Y1和TaNF-Y2。在拟南芥中进行的初步功能验证表明,这两个基因均可以提高转基因拟南芥的抗旱性。为了进一步验证它们在小麦中的功能,分别得到了TaNF-Y1转石4185和TaNF-Y2转济麦22转基因小麦T5株系。在此基础上,本研究在室内干旱胁迫和大田控水条件下,以抗旱相关生理生化指标和产量为依据,对两种转基因小麦的抗旱性进行了鉴定,进而对TaNF-Y1和TaNF-Y2基因在小麦中的抗旱功能进行了分析。主要研究结果如下:三个TaNF-Y1转基因株系与受体品种石4185相比较,在相同PEG模拟干旱胁迫条件下,转基因株系的种子发芽势、发芽率、苗期单株生物量和总根系长度都显著高于受体,而苗期离体叶片失水率和叶片相对电导率则显著低于受体,有利于保水。更为重要的是,在大田控水和正常灌溉条件下,三个转基因株系的产量都显著高于受体,且在控水条件下产量增幅更大。以上结果表明,TaNF-Y1基因在受体品种石4185中的过表达有利于增强小麦的耐旱性。三个TaNF-Y2转基因株系与受体品种济麦22相比较,大田控水和正常灌溉条件下,转基因株系的产量都显著高于受体,产量的增加主要因千粒重增高所致。灌浆期是千粒重形成的关键时期,这一时期在室内控水处理下,三个TaNF-Y2转基因株系的叶片丙二醛含量和叶片相对电导率显著低于受体品种济麦22,而可溶性蛋白含量显著高于受体品种济麦22;孕穗期室内控水试验结果与灌浆期一致。以上结果表明,TaNF-Y2基因在受体品种济麦22中的过表达有利于增强小麦抵御干旱胁迫的能力。
[Abstract]:Wheat is one of the main food crops in China, and its yield is directly related to food security. Wheat production is often affected by drought. It is very important to discover drought-related genes and develop new drought-resistant varieties by molecular breeding. It has been shown that transcription factor gene is an important candidate gene source for drought resistance. Two NF-Y transcription factor genes, TaNF-Y1 and TaNF-Y2, were screened from drought transcription profiles of wheat. Preliminary functional verification in Arabidopsis thaliana showed that the two genes could improve drought resistance of transgenic Arabidopsis thaliana. In order to further verify their function in wheat, the transgenic wheat T5 lines of TaNF-Y1 and TaNF-Y2 transferred to Jimai 22 were obtained, respectively. On this basis, the drought resistance of two transgenic wheat was identified under indoor drought stress and field water control, based on physiological and biochemical indexes related to drought resistance and yield. The drought resistance function of TaNF-Y1 and TaNF-Y2 genes in wheat was analyzed. The main results are as follows: the seed germination potential and germination rate of three TaNF-Y1 transgenic lines were compared with the recipient variety Shi 4185 under the same PEG simulated drought stress. Biomass per plant and total root length of seedling stage were significantly higher than that of receptor, while the rate of water loss and relative conductivity of leaves in seedling stage were significantly lower than those of receptor, which was beneficial to water conservation. More importantly, under the condition of field water control and normal irrigation, the yield of the three transgenic lines was significantly higher than that of the receptor, and the yield increased even more under the condition of water control. The results indicated that the overexpression of TaNF-Y1 gene in the recipient variety Shi 4185 was beneficial to enhance wheat drought tolerance. The yield of the three TaNF-Y2 transgenic lines was significantly higher than that of the recipient lines under field water control and normal irrigation, and the increase of yield was mainly due to the increase of 1000-grain weight. The filling stage is the key period for the formation of 1000-grain weight, which is controlled by indoor water treatment. The malondialdehyde content and relative conductivity of leaves of the three TaNF-Y2 transgenic lines were significantly lower than those of the recipient variety Jimai 22, while the content of soluble protein was significantly higher than that of the recipient variety Jimai 22, and the results of indoor water control experiment at booting stage were consistent with those of grain filling stage. The results indicated that the overexpression of TaNF-Y2 gene in the recipient variety Jimai 22 was helpful to enhance the ability of wheat to resist drought stress.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S512.1

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