Early development is a critical stage in a plant's life, as the plant must establish itself in the ecosystem during this period. The secondary metabolites (SM) during this phase is a strategy that contributes to the survival of plant species. Through a review of the literature, a number of reports were found that investigated the presence of SM during germination and early plant development (phases 0 and 1 according to the Zadoks and BBCH scales). A total of 250 reports were found that investigated 99 species and nearly 200 SM that accumulate during this period of the plant life cycle. A large portion of the SM are biosynthesised de novo, whereas the remainder are derived in part or in total from the mother plant. In many cases, the resources for biosynthesis are supplied only by the reserve material of the endosperm or cotyledons, which allows for independent photosynthesis. The presence of SM at these stages confers characteristics of more advanced stages, such as tissue-specific distribution, spatio-temporal regulation, and the individual regulation of all of the biosynthesised SM. The amount and diversity of SM are not universally related to the progress of plant development, but it is a widespread phenomenon. The early production of SM has ecological implications that involve defence mechanisms, relationships with microorganisms, and the role of these compounds as nitrogen reserves. This review contributes to the systematisation of studies on SM in the early stages of development.

The benzylisoquinoline alkaloids (BIA) are specialized metabolites with an ancient phylogenetic distribution, but still preserved in modern clades. Some of them, such as morphine, sanguinerine or berberine, are important for modern medicine. This review discusses the highlights of the current state of the biosynthesis of BIA. There have been studies that show the biosynthesis of 22 of these nitrogenous metabolites. In their formation there are 43 enzymes grouped into oxidoreductases, transferases and lyases, which in some cases represent atypical examples of the manner in which the secondary metabolism diversification was<br />originated. Two of these examples are the cytochrome proteins P450 (P450), with catalytic activities for ABI route, or the norcoclaurine synthase enzyme (NCS), which share substantial identity with defense allergenic proteins. Likewise, there are genetic advances that have produced the characterization of 30 enzymes, allowing knowledge of regulatory processes. Another interesting aspect is the compartmentation of the biosynthesis sites and accumulation of BIA, since in several cases they are spatially separated and in different species, or in the same species several types of cells may be involved. This has suggested intra and intercellular transport of alkaloids, precursors and enzymes, and it has been documented berberine transport between the cytoplasm and the vacuoles of storage. The picture for the biosynthesis of BIA has been constructed with exemplary studies of alkaloids with pharmacological importance.<br /><strong>Key words</strong>: specialized metabolism, secondary metabolism, cellular transport, cell compartment, tissue-specific regulation