Fig. 2.

Hypothesized epigenetic regulation of seed germination. During seed development, global CHH methylation levels (black line) increase, whereas the cell division rate (red line) decreases toward maturation. Under conditions that are favorable for germination, cell division is induced, leading to passive CHH demethylation. Cell division-related genes whose expression levels are upregulated in response to germination are often located near regions affected by CHH methylation reconfigurations. According to this model, reconfiguration of CHH methylation may help to regulate the seed germination process.