Identification of candidate genes for an early-maturing soybean mutant by genome resequencing analysis

Flowering is indicative of the transition from vegetative to reproductive phase, a critical event in the life cycle of plants. In this study, we performed whole genome resequencing by Illumina HiSeq to identify changes in flowering genes using an early-flowering phenotype of soybean mutant line Josaengserori (JS) derived from Korean landrace, Seoritae (SR), and we obtained mapped reads of 131,769,690 and 167,669,640 bp in JS and SR, respectively. From the whole genome sequencing results between JS and SR, we identified 332,821 polymorphic SNPs and 65,178 indels, respectively. Among these, 30 flowering genes were in SNPs and 25 were in indels. Among 30 flowering genes detected in SNPs, Glyma02g33040, Glyma06g22650, Glyma10g36600, Glyma13g01290, Glyma14g10530, Glyma16g01980, Glyma17g11040, Glyma18g53690, and Glyma20g29300 were non-synonymous substitutions between JS and SR. Changes in Glyma10g36600 (GI), Glya02g33040 (AGL18), Glyma17g11040 (TOC1), and Glyma14g10530 (ELF3) in JS affected the expression of GmFT2a and resulted in early flowering. These results provide insight into the regulatory pathways of flowering in soybean mutants and help to improve our knowledge of soybean mutation breeding.