This 2014 Geneva/Cambridge plant study ended by stating:
“The unequivocal demonstration of transgenerational transmission of environmentally-induced epigenetic traits remains a significant challenge.
One of the critical activities erasing stress memories is conserved between plants and mammals.”
However, the researchers didn’t demonstrate that their findings were broadly applicable for mammals or organisms other than the specific plant variety they studied. Possible reasons for these limited findings were given in a 2015 Australian study referenced by Mechanisms of stress memories in plants:
“The majority of DNA methylation analyses performed in plants to date have focused on Arabidopsis, despite being relatively depleted of TEs [transposable elements] (15–20% of the genome) and being poorly methylated compared to other plant genomes.
These studies have lacked the resolution to provide the specific context and genomic location of the changes in DNA methylation.”
There are also significant differences in how epigenetic inheritance across generations may operate among different species per Epigenetic reprogramming in plant and animal development, to cite one relevant summary study.
Neither the current study nor the summary study addressed the behavioral aspect of stress-induced epigenetic inheritance across generations. For example, the behavior of a mother whose DNA was epigenetically changed by stress can induce the same epigenetic changes to her child’s DNA when her child is stressed per One way that mothers cause fear and emotional trauma in their infants:
“Our results provide clues to understanding transmission of specific fears across generations and its dependence upon maternal induction of pups’ stress response paired with the cue to induce amygdala-dependent learning plasticity.”
http://www.pnas.org/content/111/23/8547.full “Identification of genes preventing transgenerational transmission of stress-induced epigenetic states”