Effect of increased carbon dioxide concentration on the elements Ca, Fe, K, Mg, Mn, and Na in Senna reticulata

The CO2 is the main gas responsible for the greenhouse effect, and assessing its effects on plant species is crucial for future research. The aim of this study was to test the impact of increased CO2 on the elements Ca, Fe, K, Mg, Mn, and Na in leaflets, roots, and stems of Senna reticulata. The plants were exposed to 360 mg.kg-1 and 720 mg.kg-1 of CO2 in a controlled environment. The samples were solubilized with HNO3 and analyzed by flame atomic absorption spectrophotometry. The increase in CO2 to 720 mg.kg-1 resulted in a 56.05% increase in Ca in the root, with reductions in the leaflet (1.11%) and stem (10.21%); reduction of Fe in all parts (leaflet 1.99%, root 19.16%, stem 41.73%); reduction of K in the leaflet (15.40%) and increases in the root (35.42%) and stem (3.17%); increase in Mg in all parts (leaflet 15.06%, root 111.46%, stem 6.15%); reduction of Mn in the leaflet (19.97%) and stem (16.69%) and increase in the root (1.47%); and reduction of Na in the leaflet (52.59%) and increases in the root (234.73%) and stem (168.38%). Exposure to 720 mg.kg-1 of CO2 induces adaptations in the distribution of elements in Senna reticulata compared to exposure to 360 mg.kg-1.