[Preface to the special issue: biosynthesis of natural products].

Natural products, important sources of innovative drugs, food, spices and daily chemicals, are closely related to people's healthy life. With the development and integration of modern biological and chemical technologies of natural products, the researches on biosynthesis of natural products have made great progresses in recent years. The biosynthetic pathways of a number of natural products have been analyzed. Many pathway enzymes and modifying enzymes involved in the biosynthesis of natural products have been mined and functionally characterized. Furthermore, genes encoding pathway enzymes have been introduced into chassis to construct cell factories producing natural products through synthetic biology technologies. Also, other biotechnologies including genome editing and genome mining, have been used in the biosynthesis of natural products. In order to further promote the development of researches on biosynthesis of natural products, we edited a Special Issue on the topic of "biosynthesis of natural products", focusing on the researches progress in three aspects: the analysis of biosynthetic pathways of natural products, genome-wide mining and functional characterization of genes encoding tool enzymes, and the scale preparation of natural products by biosynthetic technology. Also included in this Special Issue was the prospect of the biosynthesis of natural products. This Special Issue can provide reference and guidance for the further development of natural product biosynthesis.