Plants depend on LEAFY protein that enables cells to change their fate Cells don't express all the genes they contain all the time. The portion of our genome that encodes eye color, for example, doesn't need to be turned on in liver cells. In plants, genes encoding the structure of a flower can be turned off in cells that will form a leaf. These unneeded genes are kept from becoming active by being stowed in dense chromatin, a tightly packed bundle of genetic material laced with proteins. In a new study in the journal Nature Communications, biologists from the University of Pennsylvania identified a protein that enables plant cells to reach these otherwise inaccessible genes in order to switch between different identities.