When a Pokémon with Protosynthesis is in harsh sunlight or is holding Booster Energy, its highest stat (other than HP and taking into account stat stages, but not held items) is increased by 30%, or 50% if Speed is the highest stat. Protosynthesis will activate in harsh sunlight even if the Pokémon is holding a Utility Umbrella.
Harsh sunlight will activate Protosynthesis before a held Booster Energy, so the Booster Energy will not be consumed if the Pokémon with Protosynthesis is in harsh sunlight.
Skill Swap and Doodle fail if either Pokémon has Protosynthesis. Worry Seed and Gastro Acid will fail if the target has Protosynthesis.