Wei Xue, Lin Huang, Fei-Hai Yu, T. Martijn Bezemer
This is a plain language summary of a Functional Ecology research article that can be found here.
It is a common phenomenon in humans, animals, and plants that environmental conditions experienced by a parent can influence their offspring. In plants, this effect can act through both parental effects (i.e. characteristic changes of the parent due to environment factors can be transmitted to and have influences on offspring generation), and soil legacy effects (i.e. soil property changes of the parent, due to environment factors, can further influence offspring generation that grow later in this soil). Ecologists are beginning to notice the importance of both parental effects and soil legacy effects in plant growth, but we lack the knowledge of how the two effects may act simultaneously to regulate offspring performance.
To fill this knowledge gap, we first grew parent plants of common pennywort (Hydrocotyle vulgaris) under ambient and shade light conditions. The parent plants were treated with a DNA demethylation agent (5-azacytidine) to block parental effect, or with water to allow parental effect. After three months, we collected the soils and offspring; hence we had four types of soil and four types of offspring that had been generated by the ambient and shaded parent plants treated with 5-azacytidine or water. Then, we grew the four types of offspring separately in each of the four different soils, and they were put under either ambient or shade light conditions.
We found that offspring produced by the parent exposed to ambient light conditions grew larger than offspring produced by the parent exposed to shade light conditions, indicating a “silver spoon” effect. However, the effect of parental light conditions varied depending on the soil that had been altered by the parent, the DNA demethylation status of the parent, and the offspring light condition. Moreover, offspring growth was associated with fungal composition and total phosphorus in the soil that had been altered by the parent.
These results indicate that light condition experienced by parents can influence offspring responses to light through both parental effects—mediated by changes in DNA methylation—and soil legacy effects due to plant-mediated changes in a combination of soil biotic and abiotic properties. Future studies should examine whether this phenomenon is generally true in other plants.