Work

Modulating terpenoid biosynthesis in mint (Mentha spicata L.) through the application of narrowband UV-B and UV-A wavelengths

Year: 2026

Type: article

Abstract: The characterisation of photoreceptor signalling pathways, combined with recent advancements in LED lighting technology, has opened new opportunities for using narrowband UV wavelengths to selectively enhance activity of specific plant metabolic pathways by applying the most effective wavelengths, while minimizing undesired UV-induced responses. This approach can be hypothesised to enable growers to increase secondary metabolite content in horticulturally relevant crops. This study investigated how different narrowband UV-A and UV-B wavelengths (310, 325, 340, and 365 nm) modulate monoterpene and sesquiterpene accumulation, as well as the expression of key regulators in the terpenoid biosynthesis pathway in Mentha spicata L. Mint plantlets. Results show that shorter UV wavelengths, particularly 310 nm and 325 nm, were effective in enhancing accumulation of specific monoterpenes such as α-pinene, thujene, β-pinene and limonene. Longer UV wavelengths were considerably less effective in driving accumulation of these monoterpenes. Sesquiterpene accumulation was not significantly affected by any UV wavelength. Thus, this study shows wavelength-specific accumulation of terpenes, particularly monoterpenes in plants exposed to 310 nm UV-B. Interestingly, gene expression profiling revealed that the majority of targeted transcripts, encoding key enzymes in the terpenoid pathway, displayed the strongest upregulation when mint plants were exposed to 340 nm UV. This finding highlights the complexity of regulation of the terpenoid biosynthesis pathway, and the potential of narrowband UV treatments as a precise tool to modulate the synthesis of specific secondary metabolites in crops of horticultural interest.

Source: Journal of Experimental Horticulture

DOI: 10.1016/j.jxh.2026.100008