Transgenerational hormesis: What do parents sacrifice for their offspring

Transgenerationally acquired information equips offspring with tools essential for enhancing their physiological functioning, reproduction, survival, and tolerance to a plethora of environmental stressors. To provide a perspective for a better understanding of the effects of contaminants, organismal stress biology, and their implications to environmental and agricultural health, this report presents an overview of evidence of transgenerational hormesis induced by various environmental stressors in animals, plants, and microbes. Transgenerational effects of stress are analyzed within a dose-response framework, dissecting subNOAEL (no-observed-adverse-effectlevel) effects from sublethal, superNOAEL effects. SubNOAEL effects can lead to beneficial effects in both parents and offspring. Conversely, in the case of sublethal, superNOAEL stress, parents may sacrifice their own health and survival for the benefit of offspring and their species. In this case, offspring often exhibit enhanced growth, reproduction, survival, and tolerance to stress; however, important risks exist, with effects alternating between inhibition and stimulation across generations. Results are discussed within a mechanistic framework.