Study on the Relationship between the Ubiquitination of Histones on Chromosomes and the Physiological Male Sterility Induced by Chemical Hybridizing Agent SQ-1 in Wheat(Triticum aestivum L.)
摘要小麦(Triticum aestivum L.)杂种优势利用与雄性不育机理的研究，多年来一直是世界性设法攻克的科学难关。为了研究小麦生理型雄性不育与组蛋白泛素化的关系，进而为揭示小麦生理型雄性不育的机理奠定基础。以小麦品种西农1376为供试材料，化学杂交剂SQ-1为雄性不育诱导剂，首先创建其可育与不育等生理系，然后提取两者的组蛋白，采用Western blot 的方法研究其泛素化水平;克隆出催化组蛋白H2B泛素化的E2酶基因RAD6的cDNA功能序列，并对其进行生物信息学分析，同时采用实时荧光定量PCR技术分析RAD6基因的表达特性。结果显示，在小花发育的3个时期，组蛋白H3的泛素化修饰水平在可育株与不育株之间无明显差异。在单核期，组蛋白H2A的泛素化修饰仅发生在可育株中，而不育株中没有发生;组蛋白H2B的泛素化水平在不育株中明显低于可育株，同时不育株中RAD6基因的表达明显受到抑制。这些均表明，在小麦生理型雄性不育败育关键期(单核期)，不育株小花中RAD6基因的表达显著下降，同时其催化的组蛋白H2B泛素化水平也明显下降，以及组蛋白H2A没有泛素化修饰，可能影响某些关键基因的转录而导致小麦败育。由此可见，小麦组蛋白泛素化水平与生理型雄性不育密切相关，这为小麦生理型雄性不育组蛋白泛素化调控机制提供了科学依据，进而为深入探究小麦生理型雄性不育机理提供了坚实的表观遗传研究基础资料。
Abstract：Wheat(Triticum aestivum L.) as the main food crop, studying its utilization of heterosis and male sterility is the matter that has been tried to overcome in the world. To deeply research the mechanism of the physiological male sterility of wheat, the relationship between the ubiquitination of histones and the physiological male sterility was studied, which based on the research front of histone modifications. Used physiologically male sterility induced with chemical hybridizing agent SQ-1 and corresponding normal lines of complete fertility as experimental materials in wheat, investigated the rate of the physiological male sterility as well as their pistil fertility. The histones were extracted from the two lines' flowers. The ubiquitination levels of the histones were monitored with Western blot, and then cloned the cDNA functional sequence of RAD6, which was identified as an ubiquitin-conjugating enzyme of histone H2B. Bioinformatics technique was applied to analyze RAD6 such as sequence multiplication, constructed a phylogenetic tree, forecasted secondary structure and 3D structure of RAD6. Lastly, qRT-PCR was performed to analyze the expression of the RAD6 gene. The results showed that the chemical hybridizing agent SQ-1 had a sound effect on mile-killing. The ubiquitination level of histone H3 was almost the same between the male sterile and fertile lines. During mononuclear period, the ubiquitination of histone H2A was seemed to be existing in fertility, but disappearing in the sterility ones; the ubiquitination level of histone H2B in physiological male sterile wheat was seemed to be significantly less than that in fertile ones, meanwhile, the expression of the RAD6 gene in sterility wheats was apparently suppressed. These data indicated that SQ-1 distinctly restrained the ubiquitination levels of histones H2A, H2B as well as the expression of the RAD6 gene in the mononuclear period, which may be influencing the translation of some key genes and evently result in physiological male sterility in wheat. Thus, it can be seen that there is a close relationship between the ubiquitination of the histones on chromosomes and the physiological male sterility induced by the chemical hybridizing agent SQ-1 in wheat. The research supplies scientific evidence for the ubiquitination of histones involve in the wheat physiological male sterility, meanwhile, it establishes the solid epigenetics study foundation for wheat physiological male sterility mechanism.
桑青1,刘红占2,张改生1,朱启迪2,祝万万3,张龙雨4,车会学3. 小麦染色体组蛋白泛素化与生理型雄性不育相关性的研究[J]. , 2013, 21(4): 396-406.
, , , , , ,. Study on the Relationship between the Ubiquitination of Histones on Chromosomes and the Physiological Male Sterility Induced by Chemical Hybridizing Agent SQ-1 in Wheat(Triticum aestivum L.). , 2013, 21(4): 396-406.
