Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Agriculture & Forestry University, Fuzhou, Fujian, China.
Fujian Provincial Key Laboratory of Crop Breeding by Design, Fujian Agriculture & Forestry University, Fuzhou, Fujian, China.
PLoS One. 2019 Jan 14;14(1):e0210596. doi: 10.1371/journal.pone.0210596. eCollection 2019.
Chemical mutagenesis is a useful tool for inducing mutations in plants. Seeds are often used as the material for chemical mutagenesis. The biological effect of a chemical mutagen on seeds is determined by absorption dose (the product of mutagen concentration and acting time, which starts after the mutagen is absorbed by the seeds). In practice, however, the concept of exposure dose (the product of mutagen concentration and treating time) is usually used instead because the time for absorbing mutagen is unknown. In this study, we conducted an experiment using ethyl methane sulphonate (EMS) to treat cauliflower seeds, in which five EMS concentrations (0%, 0.5%, 1.0%, 1.5% and 2.0%), three treating time lengths (4 h, 6 h and 8 h) and two pretreatments (non-presoaking and presoaking of seeds for 2 h) were set. We obtained a well-fitted nonlinear regression model for the relationship between seedling survival rate and the EMS treatment, and its marginal models for the two pretreatments. Based on the models, we determined the EMS absorption doses under the two different pretreatments and identified their 50% lethality dose (LD50). We found that presoaking could delay EMS absorption and therefore reduce the injury caused by EMS within a given treating time, but could hardly change the biological effect of EMS after it is absorbed. The conclusions about absorption dose and presoaking effect obtained in this study might be generally applicable to plant chemical mutagenesis in principle.
化学诱变是在植物中诱导突变的有用工具。种子通常被用作化学诱变的材料。化学诱变剂对种子的生物效应由吸收剂量（诱变剂浓度和作用时间的产物，在诱变剂被种子吸收后开始）决定。然而，在实践中，通常使用暴露剂量（诱变剂浓度和处理时间的产物）的概念，因为吸收诱变剂的时间是未知的。在这项研究中，我们使用乙磺酸乙酯（EMS）处理花椰菜种子进行了实验，其中设置了五个 EMS 浓度（0%、0.5%、1.0%、1.5%和 2.0%）、三个处理时间（4 小时、6 小时和 8 小时）和两种预处理（不浸泡和浸泡种子 2 小时）。我们获得了种子存活率与 EMS 处理之间关系的良好拟合非线性回归模型，以及两种预处理的边际模型。基于这些模型，我们确定了两种不同预处理下的 EMS 吸收剂量，并确定了它们的 50%致死剂量（LD50）。我们发现，浸泡预处理可以延缓 EMS 的吸收，从而在给定的处理时间内减少 EMS 造成的伤害，但在 EMS 被吸收后，几乎不会改变 EMS 的生物学效应。本研究中关于吸收剂量和浸泡预处理效果的结论原则上可能普遍适用于植物化学诱变。
