Chilling-stress modifies DNA methylation level in cucumber (Cucumis sativus L.) seedling radicle to regulate elongation rate

•Cucumber radicle elongation slowed with chilling or 5-azacytidine application.•Chilling correlated with higher global methylation.•Rewarming partially restored radicle growth with higher demethylation.•5-azacytidine interfered with methylation state at specific sites.•Insight into the dynamics of methylation in a chilling-sensitive crop was provided.