Drought response across developmental transitions: insights into the role of vegetative phase change

Developmental transitions impact ecology and evolution by altering the way plants interact with their environment. Studies of germination and flowering show that developmental timing has significant impacts on plant fitness and performance, but very little attention has been given to the juvenile-to-adult transition: vegetative phase change (VPC). In this study we used 157 diverse genotypes of Arabidopsis thaliana to investigate how plants differentially respond to drought across vegetative development from both physiological and genomic perspectives. 

We found that the timing of vegetative phase change has significant impacts on plant performance in response to drought stress and that the developmental phase of a plant (i.e., juvenile or adult) alters the impacts of drought on plant growth and fitness. We found significant relationships between the timing of VPC and climate-of-origin, indicating that the timing of this transition may contribute to both adaptation and acclimation in plants. Finally, we conducted a genome-wide association study and identified genetic loci associated with differential response to drought stress, and natural variation in the timing of VPC. Our study provides further evidence that vegetative phase change results in important physiological shifts in plants that contribute to their success and should not be overlooked.