【作者】 颜艳；

【导师】 管清美；

【作者基本信息】 西北农林科技大学 ， 果树学， 2018， 硕士

【摘要】 苹果(Malus×domestica)是世界四大水果之一。西北黄土高原是苹果的优质产区,但是降水量较少且季节分配不均匀,对苹果产业的发展产生了不利影响。因此,从苹果中鉴定响应干旱的基因并对其功能进行深入研究,对培育品质优良、抗旱性强的新品种有重大的意义。本论文从‘金冠’(Malus×domestica Borkh.cv.Golden Delicious)中克隆了MdSE(SERRATE)基因,并通过转基因手段获得了MdSE基因沉默株系和过表达株系,鉴定了MdSE基因在干旱胁迫下的功能。另外,本论文还验证了MdSE在miRNA生成中的功能。获得的主要结果如下:1.苹果MdSE基因克隆与分析。本论文成功克隆了苹果MdSE基因,对MdSE基因的分析表明,MdSE基因在苹果根、茎、叶、花、果实中均有表达,并且在花中的表达量最高。在干旱胁迫下,MdSE基因的表达量随着干旱时间的增长逐渐降低,说明MdSE基因响应干旱胁迫。2.苹果MdSE通过调节气孔开闭负调控苹果的耐旱性。MdSE转基因沉默株系对ABA敏感,而过表达株系对ABA不敏感。在MdSE基因沉默株系中,ABA合成关键基因MdNCED3的表达量显著高于野生型和过表达株系。因此,MdSE通过调控气孔的开张度负调控苹果的抗旱性。3.苹果MdSE影响miRNA的生成过程。苹果MdSE与MdHYL1互作,并且MdSE基因沉默株系中pri-miRNAs的表达量增加,成熟miRNAs的表达量减少,说明苹果MdSE参与miRNA的生成过程。更多还原

【Abstract】 Apple(Malus × domestica)is one of the most important fruit in the world.Located to the northwest of China,the loess plateau region is one of the best place for apple production.However,the rainfall in loess plateau is limited,which affects the development of apple industry seriously.Therefore,identification of drought responsive genes in apple and study of their functions have significant meanings for breeding new apple varieties with high quality and drought resistance.In this paper,we identified and cloned MdSE(SERRATE)gene in ‘Golden Delicious ’(Malus × domestica Borkh.cv.Golden Delicious),then obtained RNA interference(RNAi)and overexpression transgenic apple lines by transgenic method.Then we tested the phonotype of transgenic plants under drought.Furthermore,we verified the function of MdSE in miRNA biosynthesis.The followings are the main results.1.Clone and analysis of MdSE gene.In this paper,we cloned SE in apple.By analyzing the expression level of Md SE,we found that MdSE expressed in root,stem,leaf,flower and fruit and expressed most in flower.The expression level of MdSE was gradually decreased under drought stress,which indicated that MdSE might play role in drought stress.2.MdSE can negatively regulate drought resistance of apple by regulating the stomata aperture.The stomata movement of MdSE RNAi(RNA interference)transgenic apples were sensitive to ABA stimuli while the stomata of MdSE overexpression transgenic apples were insensitive to ABA stimuli.ABA plays important role in response to drought stress.The mRNA level of MdNCED3,the key gene of ABA biosynthesis,was higher in MdSE RNAi apples than wild type and overexpression apples.So MdSE can negatively regulate drought resistance of apple by regulating the stomata aperture.3.MdSE can affect the biosynthesis of miRNA.MdSE interact with MdHYL1.The expression level of pri-mi RNAs were higher in MdSE RNAi transgenic apples than wild type and the expression level of mature miRNAs were lower in MdSE RNAi transgenic apples than wild type,which indicated that MdSE affected the biosynthesis of miRNA.更多还原