LAUSR

Abstract Morphoanatomical and chemical changes can occur because of biotic and abiotic factors, naturally present in the environment. These changes can result in modifications in the concentrations of secondary metabolites of medicinal species, an essential aspect to produce herbal medicines. Justicia species are used for analgesic and anti-inflammatory purposes and widely used in social programs in the Northeast of Brazil. Therefore, this study aimed to evaluate how different growth conditions (greenhouse and field) affect morphoanatomical features, chemical composition and AA of the aerial organs of three economically important species of Justicia (J. brandegeeana, J. gendarussa, and J. pectoralis). The results of morphological evaluations indicate that plants grown in the field developed better than those grown in the greenhouse, which underwent etiolation. Plants grown in the greenhouse had a greater leaf area and reduced mesophyll thickness. In contrast, plants that were grown in the field had greater cuticle and mesophyll thickness, as well as increased collenchyma cell wall thickness of stems and petioles. Plants grown in the field also had a higher stomatal density than plants grown in the greenhouse. Mass spectrometric data revealed a higher overall concentration of phenols and flavonoids, as well as higher AA, in the extracts of the plants grown in the field. Thus, the different growth conditions resulted in anatomical alterations, and changes in the concentrations of some chemical components. The results help to improve the cultivation of these species, as these changes imply in the quality of the final product and the treatment.