Plants often show reduced fitness when exposed to stressful environmental conditions. Such conditions can also affect a plant’s offspring in a phenomenon called ‘transgenerational plasticity’ or ‘transgenerational effects’. In plants, such transgenerational effects can be physiological and controlled by the mother plant, for instance through endosperm or seed coat modifications. Transgenerational effects can prepare (or ‘prime’) plants for particular environmental conditions, particularly when offspring are likely to experience similar conditions as their parents. Heat stress, in particular, is known to affect plant offspring. However, it is unclear to what extent such effects depend on temporal patterns of stress, and whether transgenerational responses are adaptive and genetically variable within species.
In their new study published in AoBP, Deng et al. investigated the transgenerational effects of different temporal patterns of heat stress in nine Arabidopsis thaliana genotypes. They subjected the plants to heat stress regimes that varied in timing and frequency, but not in mean temperature. The offspring of these plants were then grown under controlled conditions as well as under renewed heat stress, with measurements of plant architecture and fecundity during the growth of the plants.
Deng et al. found that the timing of heat events is much more important than their frequency. This is consistent with the authors’ findings in previous work with the parental plants. Variation in parental stress timing consistently affected the architecture also the flowering time and biomass of offspring plants, whereas the transgenerational effects of stress frequency were only minor. Deng et al. also found that the transgenerational responses of plants to heat are related to their climates of origin, which means they can evolve and have probably already done so in the past. They suggest these results indicate the potential of natural populations as well as of crop varieties to adapt to increasingly variable climates in the future.
READ THE RESEARCH
Deng, Ying, Oliver Bossdorf, and J. F. Scheepens. 2021. “Transgenerational Effects of Temperature Fluctuations in Arabidopsis Thaliana.” AoB PLANTS. https://doi.org/10.1093/aobpla/plab064.