独行菜种子低温萌发耐受性特性及bHLH类转录因子分析

发布时间：2018-05-14 14:40

  本文选题：独行菜 + 低温萌发　； 参考：《新疆师范大学》2017年硕士论文

【摘要】：独行菜(Lepidium apetalum)是十字花科独行菜属的植物。生活在新疆北部的独行菜具有典型的早春短命植物特征,并且能够在早春寒冷天气进行萌发、生长,是良好的研究植物耐受低温逆境的材料,但目前对其耐受低温特性研究还很少。本文对独行菜种子萌发及幼苗生长对低温的耐受特性进行了研究,并进一步在转录组数据库基础上对独行菜bHLH转录因子家族进行了分析和相关基因的克隆,以期为阐述独行菜种子萌发及幼苗生长耐受低温的生理及分子机制提供研究基础。主要结果如下:(1)独行菜种子萌发对低温胁迫的生理响应的研究发现,独行菜种子在不同萌发阶段对零下低温均有良好的抗性,但随萌发进行抗性有所下降;萌发至中期的种子在4℃逆境中都能生存并生长,但生长速度显著受到抑制;萌发中期独行菜SOD、CAT活性与同工酶酶谱受低温影响都很大:胁迫初期酶活性下降,短时间内又迅速提高并维持在较高水平。(2)通过对独行菜种子转录组测序结果进行分析筛选后得到bHLH转录因子家族基因的序列共107条,去除冗余后得到其成员共83个。相对于低温萌发停滞期的独行菜种子,打破低温停滞前后的独行菜种子中有一条转录本c31476_g1在两组中的表达量完全一致,其被注释为转录因子bHLH27。(3)对独行菜种子转录组bHLH类转录因子中相关基因进行克隆和分析:其中序列c20009_g1(注释为转录因子ICE1基因)cDNA全长序列为1503bp,命名为la ICE1,编码一个分子量为54635.19KD、理论等电点pI为5.45、分子式为C2364H3742N688O758S22的蛋白质;序列c31476_g1(注释为转录因子bHLH27)的cDNA全长序列为933bp,编码一个分子量为76874.76KD、理论等电点pI为5.09、分子式为C2815H4699N933O1180S199的蛋白质;序列c17865_g1(注释为转录因子bHLH7)的cDNA全长序列为765bp,编码一个分子量为29180.96KD、理论等电点p I为4.65、分子式为C1277H2016N336O414S15的蛋白质。综合以上实验结果,对独行菜种子耐受低温萌发特性有了初步了解,而且对独行菜种子转录组中bHLH转录因子家族基因的分布情况有了全面认识,为进一步的bHLH转录因子在独行菜种子低温萌发过程中的研究奠定基础。
[Abstract]:Lepidium apetalumum is a plant of Cruciferae. The solitary vegetables living in the northern part of Xinjiang have typical early spring short-lived plant characteristics, and can germinate and grow in the cold weather of early spring. It is a good material for studying the tolerance of plants to low temperature stress. However, there are few studies on its tolerance to low temperature. In this paper, the characteristics of seed germination and seedling growth tolerance to low temperature were studied, and the bHLH transcription factor family and related gene cloning were further analyzed on the basis of transcriptional database. It is expected to provide a basis for studying the physiological and molecular mechanisms of seed germination and seedling growth tolerance to low temperature. The main results were as follows: (1) the physiological response of seed germination to low temperature stress showed that the seeds had good resistance to low zero temperature at different germination stages, but the resistance decreased with germination. The seeds from germination to middle stage could survive and grow under 4 鈩，

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