Influence of flavonoids and phenolic acids in the in vitro propagation of tamarillo shoots

A. Caeiro, S. Correia, J. Canhoto
Tamarillo (Solanum betaceum Cav.) is a Solanaceae tree native to South America. Because of its agronomic importance and the problems associated with traditional propagation methods, several biotechnological processes have been used to clone this plant. Previous studies have shown that the presence of certain secondary compounds in the culture medium, namely flavonoids and phenolic acids, influence the cellular response in terms of callus formation. Since some of these compounds can be produced naturally by the plant, the aim of this work was to determine whether exogenous concentrations affect in vitro plant growth. Phytomers from in vitro established clones were cultivated on solid Murashige and Skoog medium supplemented with sucrose (8.6 mM) and 6-Benzylaminopurine (0.88 µM). To test the influence of secondary metabolites, either caffeic acid, rutin, anthranilic acid or chlorogenic acid were added to the medium. The initial shoot length was measured and the plants were kept in a growth chamber for 7-8 weeks. After this period, growth rates were calculated as the final length NDASH initial length/growth time. Root development was measured, as well as the length of the main root and the number of leaves produced. The results show that anthranilic acid, chlorogenic acid and caffeic acid are serious inhibitors of plant growth and root formation. Plants grown with Rutin showed higher growth rate and number of leaves compared to the control (0.6473±0.1703 cm week‑1 and 9.133±2.503, respectively). However, the presence of this compound decreases the rooting process (52%) whereas the root length appears to be unaffected. Profiles of the general families of secondary compounds show that rutin has induced a markedly different secondary composition of secondary metabolites in the leaves. Further studies are underway to characterize the molecular mechanism, specifically in terms of plant chemical composition, to elucidate the molecular mechanisms influencing this response.
Caeiro, A., Correia, S. and Canhoto, J. (2023). Influence of flavonoids and phenolic acids in the in vitro propagation of tamarillo shoots. Acta Hortic. 1359, 189-196
DOI: 10.17660/ActaHortic.2023.1359.24
growth parameters, HPLC, metabolic profile, rooting, secondary compounds

Acta Horticulturae