Differential methylation of a retrotransposon upstream of a MYB gene causes variegation of lettuce leaves, which is abolished by the presence of an (AT)5 repeat in the promoter

• DOI: 10.1111/tpj.70123
• Publication Date: 2025-04-01T15:16:54Z
• Authors: Rong Tao; Jiaojiao Ma; Jinlong Qian; Yali Liu; Weiyi Zhang; Dean Lavelle; Xin Wang; Wenhao Yan; Richard W. Michel...; Jiongjiong Chen; Hanhui Kuang
• Keywords: Variegation (histology); Retrotransposon; MYB

SUMMARY Variegation, a common phenomenon in plants, can be the result of several genetic, developmental, and physiological factors. Leaves some lettuce cultivars exhibit dramatic red variegation; however, genetic mechanisms underlying this variegation remain unknown. In study, we cloned causal gene for on leaves elucidated molecular mechanisms. Genetic analysis revealed that polymorphism variegated versus uniformly is caused by an “AT” repeat promoter RLL2A encoding MYB transcription factor. Complementation tests demonstrated allele ( V ) with (AT) n numbers other than five led to leaves. was expressed spots but not neighboring green regions. This expression pattern concert relatively low level methylation retrotransposon inserted −761 bp compared high region. The presence 5 region, stabilized , resulting summary, identified novel mechanism controlling through inconsistent levels showed simple sequence specific size could stabilize expression.