Sonia Sultan’s research group studies individual developmental plasticity in response to key environmental factors, using field-sourced genotypes of annual plants as an experimental system. By illuminating how plastic responses influence function and fitness both within and between generations, these ‘eco-devo’ studies contribute to an expanded conceptual framework for adaptive variation and evolution. These findings also suggest new perspectives regarding the developmental and evolutionary roles of the genotype and highlight the intricate relationship between organisms and their environments. As co-leader of the Agency project, Sultan will be investigating the inherited effects of contrasting parental light conditions on phenotypic expression, transcriptional activity, and methylation state across the offspring life-cycle, offering a window onto the higher-order causal interactions between genotype, current environment, and previous environments.
Transgenerational effects of parental light environment on progeny competitive performance and lifetime fitness (2018)
Plant and animal parents may respond to environmental conditions such as resource stress by altering traits of their offspring via heritable non-genetic
effects. While such transgenerational plasticity can result in progeny phenotypes that are functionally pre-adapted to the inducing environment, it is unclear whether such parental effects measurably enhance the adult competitive success and lifetime reproductive output of progeny, and whether they may also adversely affect fitness if offspring encounter contrasting conditions. In glasshouse experiments with inbred genotypes of the annual plant Polygonum persicaria, we tested the effects of parental shade versus sun on (a) competitive performance of progeny in shade, and (b) lifetime reproductive fitness of progeny in three contrasting treatments.
In recent decades, the phenotype of an organism (i.e. its traits and behaviour) has been studied as the outcome of a developmental ‘programme’ coded in its genotype. This deterministic view is implicit in the Modern Synthesis approach to adaptive evolution as a sorting process among genetic variants. Studies of developmental pathways have revealed that genotypes are in fact differently expressed depending on environmental conditions. Accordingly, the genotype can be understood as a repertoire of potential developmental outcomes or norm of reaction.
Environmental stresses experienced by individual parents can influence offspring phenotypes in ways that enhance survival under similar conditions. Although such adaptive transgenerational plasticity is well documented, its transmission mechanisms are generally unknown. One possible mechanism is environmentally induced DNA methylation changes. We tested this hypothesis in the annual plant Polygonum persicaria, a species known to
express adaptive transgenerational plasticity in response to parental drought stress.