Racial Memory Resurfaces in Plants

Plants have been shown to inherit stress (this story was also run by nature, and other sources); that is, they respond to stress that their parents suffered, even though they themselves haven't been exposed to the stress themselves and (the bigger point) no noticeble genetic changes have been inherited from the parent.

What is affecting them then?

Perhaps it is a system wide intra-cellular effect that the stress factors (radiation or pathogen factors) leave in the parent; possibly with proteins to do with transcription, cellular membranes, or some other cell function... the net result being that the offspring seem to have a predisposition to homologous recombination - a known DNA repair tool.

This whole thing was stumbled upon by accident too.

It does highlight that non-(directly)-genetic factors may possibly be involved in trait inheritence and generation (as well as DNA repair, homologous recombination generates mutants, its a biologically random repair system).