Sure! So, there's this mechanism called "methylation" that can turn off which genes are expressed at different times/in different tissues. It occurs in almost all organisms, but we don't fully understand the role it plays across different tissues in plants. However, the evidence suggests it may play a significant role in cells going from being stem cells (as in can become many kinds of cell, not literally part of the stem), to being the tissue they ultimately end up as. Better understanding this may help us figure out why some plants can easily be vegetatively propagated, while others are more picky about it.