Efeitos da microgravidade simulada através de um clinostato 2-D sobre a espécie Plukenetia volubilis L. (EUPHORBIACEAE)

Abstract

Plants have been important to humanity since the beginning of its history, being used for food, shelter, therapeutic purposes and in many other use. One of the stimuli that determine the development of these organisms, altering their genotype and phenotype, is gravity, which is present and active all over planet Earth. Microgravity has been considered an inducer of oxidative stress and can alter aspects such as the morphology and biochemical profile of plants. In this study, we look to verify what morphological and biochemical changes could occur in the species Plukenetia volubilis Linneo, called Inca peanut, when subjected to simulated microgravity conditions using a 2-D clinostat. The experiment was carried out using 3 rotation speeds per minute (35, 50 and 75 RPM), as well as a control group (0 RPM) which was not subjected to the equipment. Morphological data was collected weekly for two months, and at the end of this period an aqueous extract was produced from the leaves of the plants in each treated group and the control group. Few morphological changes were observed, and none of the aspects evaluated showed statistically significant changes. The results presented here show the morphological and metabolic behavior of this species under simulated microgravity conditions, and its potential for use in the pharmaceutical, food and other industries, as well as other biotechnological applications. However, a high rate of chlorosis, or loss of green pigmentation, was observed in the leaves of the group treated with the 75 RPM speed, with up to 50% of the plants showing this alteration. With regard to the biochemical profile of the plants, protein content and phenolic compounds, products of secondary metabolism also known as special metabolites, were measured from the aqueous extracts. For phenolics, a decrease in levels was observed in the extracts produced from the groups treated at 75 RPM and 35 RPM, with decreases of 56.85% and 13.02% respectively, compared to the control group. The 50 RPM group showed a small increase of 7.76% in the concentration of these special metabolites, but this was not statistically significant. For proteins, based on the Bradford method, there was a significant increase in protein concentration in all the extracts produced from the groups treated with simulated microgravity. The 75 RPM group stood out, with an increase of 137.5% compared to the control group, followed by the 35 RPM group with 71.59% and the 50 RPM group with 37.5%. The results found here shed some light on the morphological and metabolic behavior of this species under simulated microgravity conditions, and its potential for use in the pharmaceutical, food and other industries, as well as other biotechnological applications.