Examining the molecular mechanisms contributing to the success of an invasive species across different ecosystems

Invasive species provide an opportune system to investigate how populations respond to new environments. Baby's breath (Gypsophila paniculata) was introduced to North America in the 1800s and has since spread throughout the United States and western Canada. We used an RNA‐seq approach to explore how molecular processes contribute to the success of invasive populations with similar genetic backgrounds across distinct habitats. Transcription profiles were constructed from seedlings collected from a sand dune ecosystem in Petoskey, MI (PSMI), and a sagebrush ecosystem in Chelan, WA (CHWA). We assessed differential gene expression and identified SNPs within differentially expressed genes. We identified 1,146 differentially expressed transcripts across all sampled tissues between the two populations. GO processes enriched in PSMI were associated with nutrient starvation, while enriched processes in CHWA were associated with abiotic stress. Only 7.4% of the differentially expressed transcripts contained SNPs differing in allele frequencies of at least 0.5 between populations. Common garden studies found the two populations differed in germination rate and seedling emergence success. Our results suggest the success of G. paniculata in these two environments is likely due to plasticity in specific molecular processes responding to different environmental conditions, although some genetic divergence may be contributing to these differences. To better understand how molecular processes may be contributing to invasion success, we used an RNA‐seq approach to examine the differences in both gene expression profiles and identified SNP differences in differentially expressed genes for populations of Gypsophila paniculata (perennial baby's breath) growing at opposite ends of the species’ introduced range in the United States. We found that the majority of genes differentially expressed between these populations reflect the different environmental conditions between these two ecosystems; however, only 7.4% of the differentially expressed genes contained SNPs that differed in allele frequency between the two populations. We suggest that the success of invasive G. paniculata is likely the result of plasticity in molecular processes responding to different environmental conditions, although some genetic divergence over the past 100 years may also be contributing to these differences.