低能N+辐照拟南芥诱导基因组DNA碱基变异分析

用低能N+离子束注入拟南芥后获得的稳定突变体T80Ⅱ作为实验材料, 对突变体植株进行了RAPD标记, 并将T80Ⅱ和对照部分RAPD特异条带进行克隆测序和DNA序列分析. 结果显示, 在可分辨的总计397个RAPD条带中, T80Ⅱ株系中有52个条带表现出差异, 包括条带的缺失和增加, 条带变异率为13.1%; 克隆的T80Ⅱ序列中, 平均每16.8个碱基出现1个碱基变异位点, 表现出较高频率的碱基突变. 碱基突变类型包括碱基的颠换、转换、缺失、插入等. 在检测到的275个碱基突变中, 主要是单碱基置换(97.09%), 碱基缺失或者插入的比例较小(2.91%). 在碱基置换中, 转换的频率(66.55%)高于颠换的频率(30.55%). 此外, 构成DNA的4种碱基均可以被离子束辐照诱发变异, 而且每一种碱基都可以被其他3种碱基所替换, 但是胸腺嘧啶(T)的辐射敏感性要高于其他3种碱基. 通过分析突变碱基周边序列, 对低能N+离子注入拟南芥突变体引发的碱基突变热点进行了讨论.     

低能N+辐照拟南芥诱导基因组DNA碱基变异分析

用低能N~+离子束注入拟南芥后获得的稳定突变体T80Ⅱ作为实验材料,对突变体植株进行了RAPD标记,并将T80Ⅱ和对照部分RAPD特异条带进行克隆测序和DNA序列分析。结果显示,在可分辨的总计397个RAPD条带中,T80Ⅱ株系中有52个条带表现出差异,包括条带的缺失和增加,条带变异率为13.1％;克隆的T80Ⅱ序列中,平均每16.8个碱基出现1个碱基变异位点,表现出较高频率的碱基突变。碱基突变类型包括碱基的颠换、转换、缺失、插入等。在检测到的275个碱基突变中,主要是单碱基置换(97.09％),碱基缺失或者插入的比例较小(2.91％)。在碱基置换中,转换的频率(66.55％)高于颠换的频率(30.55％)。此外,构成DNA的4种碱基均可以被离子束辐照诱发变异,而且每一种碱基都可以被其他3种碱基所替换,但是胸腺嘧啶(T)的辐射敏感性要高于其他3种碱基。通过分析突变碱基周边序列,对低能N~+离子注入拟南芥突变体引发的碱基突变热点进行了讨论。     

Changes in DNA base sequences in the mutant of Arabidopsis thaliana induced by low-energy N+ implantation

Arabidopsis thaliana (L.) Heynh has many advantages for genome analysis, including a short generation time, small size, large number of offspring, and a relatively small nuclear genome in comparison to other angiosperms and contains a low proportion of repetitive DNA comparatively. Furthermore, the analysis of the completed genome sequence of A. thaliana has been reported[1]. Low-energy ion implantation has attracted more and more attention from researchers in China and Japan since recent s…     

甜菜碱与植物耐盐基因工程

向非甜菜碱积累植物导入甜菜碱合成途径是提高植物耐盐性的策略之一。甜菜碱是一种无毒的有机小分子化合物。盐胁迫下,它能在植物细胞中迅速积累以维持细胞的渗透平衡,并对胞内的一些重要酶类起保护作用。编码甜菜碱合成酶的基因已被克隆,并应用于植物耐盐基因工程。本文介绍了甜菜碱的生理作用、合成酶及相关基因的特性,并结合本实验室的工作对甜菜碱基因工程及其进展作了简单的综述。     

Changes in DNA base sequences in the mutant of <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis> induced by low-energy N<Superscript>+</Superscript> implantation

To reveal the mutation effect of low-energy ion implantation on Ambidopsis thaliana in vivo, T80II, a stable dwarf mutant, derived from the seeds irradiated by 30 keV N⁺ with the dose of 80 X 10¹⁵ ions/cm² was used for Random Amplified Polymorphic DNA (RAPD) and base sequence analysis. The results indicated that among total 397 RAPD bands observed, 52 bands in T80II were different from those of wild type showing a variation frequency 13.1%. In comparison with the sequences of A. thaliana in GenBank, the RAPD fragments in T80II were changed greatly in base sequences with an average rate of one base change per 16.8 bases. The types of base changes included base transition, transversion, deletion and insertion. Among the 275 base changes detected, single base substitutions (97.09%) occurred more frequently than base deletions and insertions (2.91%). And the frequency of base transitions (66.55%) was higher than that of base transversions (30.55%). Adenine, thymine, guanine or cytosine could be replaced by any of other three bases in cloned DNA fragments in T80II. It seems that thymine was more sensitive to the irradiation than other bases. The flanking sequences of the base changes in RAPD fragments in T80II were analyzed and the mutational “hotspot” induced by low-energy ion implantation was discussed.     

甜菜碱与植物耐盐基因工程

向非甜菜碱积累植物导入甜菜碱合成途径是提高植物耐盐性的策略之一。甜菜碱是一种无毒的有机小分子化合物。盐胁迫下 ,它能在植物细胞中迅速积累以维持细胞的渗透平衡 ,并对胞内的一些重要酶类起保护作用。编码甜菜碱合成酶的基因已被克隆 ,并应用于植物耐盐基因工程。本文介绍了甜菜碱的生理作用、合成酶及相关基因的特性 ,并结合本实验室的工作对甜菜碱基因工程及其进展作了简单的综述     

拟南芥叶片直接分化雌蕊的诱导及其RAPD分析

以拟南芥为材料，通过培养诱导首次获得了叶片上直接分化雌蕊忱一自然界罕见的拟南芥变异体，雌蕊结构典型，RAPD分析结果表明变异体DNA分子上发生了突变。