I recently performed GO enrichment analysis using GOAtools on a number of phytoplankton species and I'm trying to simplify the analysis using rvvgo. I know I need to select an orgdb but given the number of different groups I'm working with (diatoms, chlorophytes, dinoflagellates) I'm not sure what the best one to use is. Is it better to just use the generic org.db for all of them, should I use the most similar organism I can like Arabidopsis, or are there db's for each group that I can utilize?