An ethyl methanesulfonate‐induced neutral mutant‐bridging method efficiently identifies spontaneously mutated genes in rice. (2nd September 2020)

• Record Type: Journal Article
• Authors: Hu, Wei; Zhou, Tianhao; Hu, Gang; Wu, Hong; Han, Zhongmin; Xiao, Jinghua; Li, Xianghua; Xing, Yongzhong
• Is Part Of: Plant journal. Volume 104:Number 4(2020)
• Page Start: 1129
• Page End: 1141
• Publication Date: 2020-09-02
• Subjects: spontaneous mutation -- neutral mutant -- pseudo‐near‐isogenic F2 population -- bulked segregant analysis -- causal mutation; Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.14969
• Languages: English
• ISSNs: 0960-7412

Abstract

SUMMARY: Spontaneous mutants are mainly obtained from tissue culture or natural occurrences in plants. The traditional strategy for identifying spontaneously mutated genes is to continuously backcross these mutants to another variety and develop a near‐isogenic F2 population for map‐based cloning or bulked segregant analysis. However, this strategy is time‐consuming. Here, we have developed a new method to efficiently accelerate the identification process. The chemical mutagen ethyl methanesulfonate was first used to treat the wild type of the spontaneous mutants to induce thousands of neutral mutations. An induced individual without any statistically significant phenotypic changes which was compared with the wild type was chosen as the neutral mutant. The spontaneous mutant was then crossed with the neutral mutant to develop a pseudo‐near‐isogenic F2 population in which only the induced neutral mutations and the causal mutation were segregated in the genome. This population ensures that the variation of the mutated trait is controlled only by the spontaneously mutated gene. Finally, after sequencing the neutral mutant and the mutant‐type DNA pool of the F2 population the spontaneous mutation will be identified quickly by bioinformatics analysis. Using this method, two spontaneously mutated genes were identified successfully. Therefore, the neutral mutant‐bridging method efficiently identifies spontaneously mutated genes in rice, and its value in other plants is discussed. Significance Statement: Ethyl methanesulfonate (EMS) can induce thousands of single nucleotide polymorphisms as molecular markers in plants. By crossing a spontaneous mutant with the neutral mutant induced by EMS, a pseudo‐near‐isogenic F2 population is developed and only the induced neutral mutations and causal mutation are segregated in the genome. After sequencing the neutral mutant and the mutant type DNA pool of the F2 population, spontaneous mutation will be identified quickly by bioinformatics analysis.