Discovering new genetic mutations is vital for expanding genetic resources for exploring the functions and breeding applications of genes. In this study, we created new mutant populations of rice and evaluated its effectiveness by using a chemical mutagen diepoxybutane (DEB) with the expectation of manageably causing small-scale deletions that induce knock-out mutations. Compared with the more common mutagen, ethyl methanesulfonate (EMS), DEB exhibited approximately 160 times the adverse impact on the early growth of rice. At 0.3 mM, which was 1/160 the concentration of EMS in the control population, the heading date in the DEB-mutated population showed dispersion, albeit with a small standard deviation. Therefore, similar to EMS, DEB has been shown to induce DNA mutations. According to the screening of waxy mutants using the Targeting Induced Local Lesions in Genomes (TILLING) method, DEB-mutated populations had nearly similar mutation frequencies to those of EMS-mutated populations. Therefore, we successfully isolated five mutant lines from the DEB-mutated population. Some of these mutants exhibited a low-amylose phenotype, which is applicable to breeding leading to enhanced taste evaluation. To utilize these mutated alleles, we developed co-dominant DNA markers. In this study, EMS induced transition mutations, as previously reported. In contrast, DEB specifically induced transversion mutations rather than small-scale deletions contrary to our initial expectations. These results demonstrate that DEB has a novel point of action for mutation and is useful for expanding genetic resources for crops.

发现新的基因突变对于扩展遗传资源以探索基因的功能和育种应用至关重要。在这项研究中，我们创建了水稻的新突变种群，并通过使用化学诱变剂双环氧丁烷（DEB）评估了其有效性，并期望可管理地引起引起敲除突变的小规模缺失。与更常见的诱变剂甲磺酸乙酯（EMS）相比，DEB对水稻早期生长的不利影响约为160倍。在0.3 mM（即对照组中EMS浓度的1/160）下，DEB突变的种群中的抽穗期显示出分散性，尽管标准偏差很小。因此，类似于EMS，DEB已显示出诱导DNA突变的作用。根据蜡质的筛选使用靶向诱导的基因组局部病变（TILLING）方法的突变体，DEB突变的群体具有与EMS突变的群体几乎相似的突变频率。因此，我们成功地从DEB突变种群中分离出5个突变株。这些突变体中的一些表现出低直链淀粉表型，该表型适用于育种，从而增强了味觉评估。为了利用这些突变的等位基因，我们开发了共显性DNA标记。在这项研究中，EMS引起了过渡突变，如先前报道。相反，与我们最初的预期相反，DEB特异地诱导了颠覆突变，而不是小规模的缺失。这些结果表明，DEB具有突变的新颖作用，对于扩大作物遗传资源很有用。