Epigenetic variation in the callus of Brassica napus under different inducement conditions

Abstract

Tissue culture, a traditional technique broadly used for the genetic transformation and functional verification of target genes, induces epigenetic variations in transgenic acceptors of plants. This study compared the DNA methylation patterns during the callus formation of Brassica napus induced by different concentrations of 6-BA and 2,4-D through methylation-sensitive amplification polymorphism. The highest induction rate (85%) was observed in the hypocotyls cultured with 0.1 mg/L 2,4-D and the lowest methylation rate (25.09%) was detected in the hypocotyls cultured with 1.0 mg/L 6-BA. The methylation rates of the callus cultured with 0.2 and 0.05 mg/L 2,4-D were 29.99 and 28.31%, respectively. The callus induction rates were reduced to 79 and 80%. The methylation rates of the callus induced by 2.0 and 0.5 mg/L 6-BA were 28.17 and 33.98%, respectively. The callus induction rates were reduced to 76 and 74%. The expression analysis of methyltransferase under different induction conditions agreed with methylation modifications; therefore, the effects of hormones on callus induction may be partially indicated by methylation changes in B. napus genome.