Fig. 9

A schematic diagram describing gene expression regulation during callus formation from immature and mature barley embryos. Dicamba (synthetic auxin) induces cell fate transition through the auxin signalling pathway, and more genes are included in the IME system (left) than in the IM system (right). Embryonic genes BBM, LEC1, and FUS3, shoot meristem gene WUS, and root meristem gene PLT2 displayed differential expression patterns between the two systems, resulted in the production of different types of callus. Embryonic callus (left) and non-embryonic callus (right) exhibit differential regeneration potential on shoot-inducing medium (SIM). Orange represents significantly upregulated genes, while blue represents genes that were activated slightly or remained unchanged. Epigenetic modification might be involved in regulating the expression status of regulatory genes in different explants and their responses to callus induction