Química envolvida na sexualidade de plantas: estudo de Cecropia pachystachya Trécul (Urticaceae)

Abstract

The expression of sexuality in plants can give rise to dimorphisms and the allocation of resources. Although evidence of chemical sexual dimorphism has been reported for several species, few studies have investigated their existence in plants. The existence of chemical dimorphisms can impact the popular medicinal use of several species, given that male and female plants may have a different chemical composition. In this sense, the objective of this project was to evaluate and compare the chemical profile, especially secondary metabolism, of male and female individuals of C. pachystachya through a metabolomics approach. We also determined the influence of drought and flood, characteristic seasons of the Brazilian Savanna (Cerrado), on the secondary metabolism of C. pachystachya, a species that has great importance for this ecosystem, including its relationship with the human species in folk medicine. We collected leaf and inflorescence samples from 10 individuals of C. pachystachya (5 male plants and 5 female plants), every two months, for 1 year. Samples were analyzed by HPLC-DAD-MS/MS from a metabolomic analysis. We did not find evidence of sexual dimorphism in the leaf blade of this species, although seasonality seems to interfere with the intensity of flavonoids, increasing these during the drought. In the inflorescences, we found chemical dimorphisms between the staminate and pistillate inflorescences, which have differences between the expressed classes and between the metabolites found. The inflorescences, although their metabolism is influenced by sexual expression, do not seem to have their metabolism influenced by the Brazilian Savanna seasons.