Aim and main questions: The genomes and expressed genes of organisms form the basis for complex processes and interactions that ultimately translate into ecosystem properties. Within species, the coordinated expression of genes shapes their traits, and networks of gene expression modules shape community processes (e.g., primary production or metabolite synthesis). Evolution of processes and traits depends on the selective pressures on related duplication and differentiation of genes or expansion of gene families within a species. Differences between HAB taxa and resident keystone species and their involvement in community processes can be described with focus on key genes that control ecological and biochemical functions. This enables identification of functions and processes likely to respond plastically to environmental changes.

Approach: Transcriptomes from isolated key species (WP2, WP3, WP5) will be screened for gene families and signatures of adaptive evolution, with emphasis on genes involved in key ecological and biochemical functions. These results will be aligned with WP2 and WP3 to link adaptive history to potential evolution, and to identify processes that facilitate dominance under future conditions. These results will serve to define expression modules in metatranscriptomes, allowing placement of locally adapted genes and associated functional traits into a community context.

Output and deliverables: 1) Functional genomic characterization of HAB species and key resident species; 2) Identification of functions and processes likely to respond plastically to environmental change; 3) Identification of potential vulnerable functions covered by locally adapted genes and populations, thereby characterizing vulnerable aspects of current ecosystems.