The colorful world of cryptophyte phycobiliproteins

Abstract

Cryptophytes are flagellated, eukaryotic phytoplankton found in environments ranging from tea-colored ponds to the blue-water open ocean. Cryptophytes vary in color from green to red, a trait that is imparted primarily by their phycobiliprotein (PBP) accessory pigments. These PBPs have likely played a key role in the diversification of cryptophytes into a wide range of aquatic environments over their evolutionary history. This review covers the current knowledge of the origin, structure and function of cryptophyte PBPs and presents evidence for remarkable phenotypic plasticity of PBP absorption, which may help cryptophytes acclimate to changes in their environment like eutrophication ("greening"), permafrost melting ("browning") or deforestation.