Multiple simultaneous treatments change plant response from adaptive parental effects to within-generation plasticity, in Arabidopsis thaliana

In general, studies on plant phenotypic plasticity concentrate on plant responses to different levels of a single environmental factor. Under natural conditions, however, multiple environmental factors often vary simultaneously. I studied the consequences for lifetime fitness caused by single treatments or treatment combinations by investigating patterns of phenotypic plasticity within and between generations. The parental plants (3 genotypes of the annual plant Arabidopsis thaliana) received zero, one or two stress treatments at an early life-stage. The treatments included wounding, shading, chilling, and their pairwise combinations. In the second generation, offspring of treated plants received either the parental or no treatment. Offspring of non-treated plants were reared under all treatment conditions. Plants responded strongly to the treatments, especially through delayed reproduction, which positively affected lifetime fitness. Notably, treatment combinations triggered stronger p...