Development and screening of EMS mutants with altered seed oil content or fatty acid composition in Brassica napus

Abstract

SUMMARY Brassica napus is an important oilseed crop in the world, and the mechanism of seed oil biosynthesis in B. napus remains unclear. In order to study the mechanism of oil biosynthesis and generate germplasms for breeding, an ethyl methanesulfonate (EMS) mutant population with ~100 000 M2 lines was generated using Zhongshuang 11 as the parent line. The EMS‐induced genome‐wide mutations in M2−M4 plants were assessed. The average number of mutations including single nucleotide polymorphisms and insertion/deletion in M2−M4 was 21 177, 28 675 and 17 915, respectively. The effects of the mutations on gene function were predicted in M2−M4 mutants, respectively. We screened the seeds from 98 113 M2 lines, and 9415 seed oil content and fatty acid mutants were identified. We further confirmed 686 mutants with altered seed oil content and fatty acid in advanced generation (M4 seeds). Five representative M4 mutants with increased oleic acid were re‐sequenced, and the potential causal variations in FAD2 and ROD1 genes were identified. This study generated and screened a large scale of B. napus EMS mutant population, and the identified mutants could provide useful genetic resources for the study of oil biosynthesis and genetic improvement of seed oil content and fatty acid composition of B. napus in the future.

A telomere-to-telomere gap-free reference genome of watermelon and its mutation library provide important resources for gene discovery and breeding

“…The frequency of non-G/C to A/T transitions increased correspondingly, and the frequency of indels increased to 21.56%. High-impact effects on gene function were also similar to the reported 0.52% in rapeseed (Tang et al, 2020). However, with EMS seed treatment, the frequency of G/C to A/T transition reached 86.5% in rapeseed (Shirasawa et al, 2016) and 68.4% in tomato (Tang et al, 2020).…”

Reduced glucosinolate content in oilseed rape (Brassica napus L.) by random mutagenesis of BnMYB28 and BnCYP79F1 genes

“…Former studies demonstrating EMS-induced random mutagenesis in Brassicaceae crops have reported a wide range of mutation frequencies between 1/12 kb to 1/447 kb [55; 56; 57; 34; 58; 59] . In this work, we screened the EMS-mutagenized population of the winter rapeseed ‘Express617’ developed by Harloff et al (2012).…”

DELLA proteins BnaA6.RGA and BnaC7.RGA negatively regulate fatty acid biosynthesis by interacting with BnaLEC1s in Brassica napus

“…NIRS analysis was performed by a Foss NIRSystems 5000 near‐infrared reflectance spectroscope to detect SOC, which was followed as previous report (Tang et al., 2020a ). FA and oil contents were analysed by GC‐MS as previous describe (Lu et al., 2016 ).…”

“…A total of 505 B.napus accessions collected from different research institutions were grown in Wuhan for two growth seasons (2012–2013 and 2013–2014). Mature open‐pollinated seeds of the natural population were harvested and desiccated for the analysis of SOC by a Foss NIRSystems 5000 near‐infrared reflectance spectroscope, and the polymorphic SNPs of BnaRGAs and BnaLEC1s were genotyped by genomic DNA re‐sequencing (Tang et al., 2020a ). The efficient Mixed‐Model Association eXpedited (EMMAX) analyses were used for genome‐wide association analysis.…”