Seasonality and fruiting converge on megastigmanes to shape foliar metabolic plasticity in Miconia albicans (Swartz) Triana (Melastomataceae).

Abstract

Introduction: Miconia albicans is a medicinal plant widely used in traditional medicine and represents a promising candidate for phytotherapeutic drug development. Despite its widespread use, the influence of environmental seasonality and phenological state on its foliar metabolome remains poorly understood, particularly in seasonal ecosystems such as the Brazilian savanna (Cerrado Biome).

Objectives: This study aimed to evaluate the influence of seasonality and phenological state on the foliar metabolome of M. albicans by untargeted metabolomics and chemometric approaches.

Methods: Leaves of M. albicans were collected from the same individuals over an 18-month period, encompassing dry and rainy seasons and contrasting phenological states (fruiting and budding). Samples were analyzed using LC-MS-based untargeted metabolomics, and data were evaluated through multivariate analyses and univariate mixed-effects models.

Results: Twenty-five metabolites were annotated, including flavonoids, megastigmanes, tannins, and triterpenes. Fruiting exerted the strongest effect on global metabolic structure, being associated with marked convergence of foliar metabolomes and coordinated responses of specific chemical classes, such as megastigmanes and tannins. Seasonality mainly affected megastigmanes, which exhibited higher intensities in the dry season. Budding had the weakest effect with responses restricted to the triterpene pathway. Univariate analyses also revealed that all annotated megastigmanes had higher intensities in both fruiting individuals and the dry season.

Conclusion: These results demonstrate that foliar specialized metabolism in M. albicans integrates environmental and phenological signals, with megastigmanes participate in a central axis of foliar metabolic plasticity within M. albicans under dry and fruiting conditions.