Michael S. Barker, PI and Katrina M. Dlugosch, CoPI Plants are rooted in place and cannot escape harsh environmental conditions. Instead, many plant species can acclimate to varying environments by modifying their structure or growth habit. In some cases, the acclimation is visible, as in the example of plants that grow small leaves or flower earlier when the local environment becomes water stressed. In other cases, the response to environmental change is not visible because subtle biochemical or genetic modes of survival are activated. This so-called "genomic plasticity" allows plants such as invasive species to thrive in new or harsh niches compared with less responsive plants. Similarly, plants with highly duplicated genomes, termed polyploids, may acclimate better because they express more variation in diverse traits in response to environmental change. Understanding how adaptive plasticity occurs is critical to being able to predict plant responses to environmental change. This project uses the novel environmental and biodiversity data from NEON to investigate the genomic basis of plasticity. To study adaptive plasticity of plants in the NEON footprint, new sequencing technologies will be used to characterize all the genes expressed over several time periods in selected polyploids and invasive species. These results will be compared against the abundance and plant community structure of the species included in the NEON biodiversity data. The project will thus establish the foundation for an unprecedented view of how plant genomes, and their subsequent traits, change over time. The study both leverages and expands NEON's long-term data to determine how plasticity at the genome level may predict plant success. Adaptive phenotypic plasticity is one of the primary means by which species respond to climatic variation, but how plasticity functions in plant genomes is not well understood. Plasticity is not easy to identify or study because homeostasis in key traits can be maintained by plasticity at underlying levels of organization. This research circumvents this problem by using genomic measures of plasticity to track response to environmental variation in plants across the NEON network. To measure and document plasticity, the project combines transcriptome profiles from RNA sequencing of selected plants at a NEON core site with NEON surveys of plant community composition. The specific activities are to (1) identify ploidy levels in species at the Harvard Forest NEON core site and select target polyploid, diploid and invasive species for the study; (2) conduct RNA sequencing of 30 target species and (3) correlate genome plasticity with species abundance. The project leverages NEON's long-term study sites and data, while extending the power of NEON's plant diversity data to the genomic level. Measurements of genomic plasticity will provide highly relevant and comparable metrics of plastic responses to the environment across taxa, space, and time. The data and analytical tools will be publicly available through NCBI and the iPlant Collaborative, and will benefit society by providing methods to predict how plants in uncertain environments will respond to change.