Phytosterol metabolism in plants and algae, time to dive into the unknown

The chapter will provide a current understanding of the biosynthesis pathways of sterols in photosynthetic eukaryotes and most importantly of their metabolism into various sterol conjugates. The diversification of enzymes and sterol structures in simple and multicellular eukaryotes from various phylogenetic groups establishes main pathways in algae and plants. A still missing subset of enzymes appealing further research efforts gives this hot topic an unbroken interest. It is crucial indeed to describe how sterol homeostasis is achieved in plants and algae in the context of growth and metabolism coordination, which is of tremendous importance for the success of biotech and agro-industrial programs.