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Somatic embryos of anise (Pimpinella anisum) are an excellent system to investigate the biosynthesis of food‐related phenolic metabolites like anethol which is linked to differentiation. Somatic embryogenesis in anise is a two part system. The first is a 2,4‐D (2,4‐dichlorophenoxy acetic acid)‐induced embryogenic callus formation which requires optimal levels of endogenous auxin and cytokinin levels. The second is the advanced embryo development stage in the absence of 2,4‐D which requires abscisic acid to stimulate embryo growth. Our work has shown that proline and the precursors of proline (ornithine and arginine), in combination with the proline analog, azetidine‐2‐carboxylate (A2C) significantly stimulated 2,4‐D‐induced embryogenic callus formation and subsequent somatic embryo development in hormone‐free medium. Further, abscisic acid stimulated somatic embryo development in anise in the second stage. Total phenolic assays done on embryogenic tissue during 2,4‐D‐induced embryogenic callus, formation, and during abscisic acid‐mediated embryo development showed that levels were highest in embryogenic tissue induced in the presence of proline plus A2C. Total phenolic levels of developing embryos in the absence of 2,4‐D and in the presence of abscisic acid were higher than that of the control. A hypothesis for further investigation is proposed based on the potential role of the proline‐linked pentose phosphate pathway in stimulating the biosynthesis of purines and phenolic metabolites during anise somatic embryogenesis.

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