Sites of Alkaloid Formation

Abstract

Plant cells are less specialized than animal cells in their metabolic abilities. An animal cell can develop or lose some metabolic properties depending on the tissue; however, this process is mostly irreversible, e.g., there is no way known at present to reverse the development of a nerve cell or a liver cell into an embryonic one. This is true to some extent for plant cells also; usually a leaf cell performs leaf metabolism, while a root cell performs only root metabolism. Under certain conditions, it is possible to change the metabolic properties. It was shown by Steward (1964) that carrot root cells, when released from the limitations of their normal tissue environment, can undergo differentiation to form all possible types of cells, leading ultimately to an entire plantlet. Some leaves or pieces of stem can readily form roots. Therefore, owing to this metabolic versatility, one might expect that alkaloids can be formed in all cells of a plant. This may be the case in some plants, such as Ricinus communis (castor bean), but it is not universal.