Accumulation pattern of endogenous cytokinins and phenolics in different organs of 1‐year‐old cytokinin pre‐incubated plants: implications for conservation

A better understanding of phytohormone physiology can provide an essential basis to coherently achieve a conservation drive/strategy for valuable plant species. We evaluated the distribution pattern of cytokinins ( CK s) and phenolic compounds in different organs of 1‐year‐old greenhouse‐grown Tulbaghia simmleri pre‐treated (during micropropagation) with three aromatic CK s (benzyladenine =  BA , meta ‐topolin =  m T , meta ‐topolin riboside =  m TR ). The test species is highly valuable due to its medicinal and ornamental uses. Based on UHPLC ‐ MS / MS quantification, m T and m TR pre‐treated plants had the highest total CK , mostly resulting from the isoprenoid CK ‐type, which occurred at highest concentrations in the roots. Although occurring in much lower concentrations when compared to isoprenoid CK s, aromatic CK s were several‐fold more abundant in the root of m T pre‐treated plants than with other treatments. Possibly related to the enhanced aromatic CK s, free bases and ribonucleotides, plants pre‐treated with m T generally displayed better morphology than the other treatments. A total of 12 bioactive phenolic compounds, including four hydroxybenzoic acids, five hydroxycinnamic acids and three flavonoids at varying concentrations, were quantified in T. simmleri . The occurrence, distribution and levels of these phenolic compounds were strongly influenced by the CK pre‐treatments, thereby confirming the importance of CK s in phenolic biosynthesis pathways.