Determination of absorption dose in chemical mutagenesis in plants

Abstract

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.

Ethyl methanesulfonate mutant library construction in Gossypium hirsutum L. for allotetraploid functional genomics and germplasm innovation

“…In mutagenesis, suitable mutagen doses are required to achieve ideal results. It is commonly considered that mutagen doses inducing about 50% lethality (LD50) among M1 plants are appropriate due to their high mutation rates (Ke et al, 2019). In the few reported experiments of cotton treated with EMS, the experimenters followed previously published basic protocols (Herring et al, 2004;Patel et al, 2014).…”

Impact of chemical mutagenesis using ethyl methane sulphonate on tepary bean seedling vigour and adult plant performance

“…The observed variation in seed germination among the genotypes could be attributed probably to differential sensitivity to the mutagen with the least sensitive genotype exhibiting a relatively higher percent germination. The absorption of mutagens can be influenced by various factors such as the water content in the tissues of the seed ( Boros and Wawer, 2018 ; Ke et al., 2019 ). The seeds of the different tepary bean genotypes probably varied in their morphological attributes such as size, seed coat thickness and hydration capacity which could have influenced the rate of absorption of the mutagen, hence its genetic effects.…”

Current trends and insights on EMS mutagenesis application to studies on plant abiotic stress tolerance and development

“…When experimenters conduct EMS mutagenesis, they generally refer to published data and make appropriate choices based on the actual situation, instead of blindly conducting experiments according to the published data. In general, 50% of the lethality can be a good mutagenesis effect ( Ke et al., 2019 ). In fact, in order to pursue higher mutation efficiency, the lethality rate we choose generally reaches 80%.…”