Response of soybean crop to nitrogen fixation in copper-contaminated soil

• Autor(a) principal: Andreola, Daiane Sartori
• Data de Publicação: 2022
• Outros Autores: Stumm, Juliano de Oliveura, Fontanive, Daniel Erison, Coinaski, Djavan Antônio, Turchetto, Ricardo, Magalhães, Juliano Borela, Ros, Clovis da, Silva, Rodrigo Ferreira da, Souza, Eduardo Lorensi de, Barros, Sinara, Silva, Ana Paula da
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Semina. Ciências Agrárias (Online)
• Texto Completo: https://ojs.uel.br/revistas/uel/index.php/semagrarias/article/view/44689
• topic: Glycine max L.; Bradyrhizobium japonicum.; Metal pesado.; Bradyrhizobium japonicum; GlycGlycine max L. ine max L.; Heavy metal.

Copper (Cu) is an essential heavy metal for plants at adequate rates, but can be toxic to agricultural species at elevated levels. However, the use of nitrogen-fixing bacteria can be an alternative for growing soybean in Cu-contaminated areas. Tolerance to excess Cu by the roots occurs through immobilization of Cu in the cell wall, exclusion from or restricted uptake, and compartmentalization in the vacuole with soluble complexes. The objective of this study was to determine the influence of the use of fixing bacteria on the development, physiological response, and bioaccumulation of Cu in soybean cultivated in contaminated soil. The experiment was laid out in a completely randomized design, in a 7 × 2 factorial arrangement corresponding to seven rates of Cu (0, 80, 160, 240, 320, 400, and 480 mg kg-1 of soil) and two inoculation possibilities (with Bradyrhizobium japonicum and without inoculation [control]), in eight replicates. The following variables were evaluated: shoot height; stem diameter; number of grains per plant; shoot and root dry weights; leaf area; specific root surface area; Cu contents in the shoot, root, and grains; translocation factor; tolerance index; bioconcentration factor; bioaccumulation coefficient; chlorophyll parameters; and number and dry weight of nodules. Inoculation with B. japonicum increases the physiological traits of plant height, specific root surface area, and grain yield in soybean grown in Cu-contaminated soil. Soybean has low efficiency in translocating Cu to the shoot; however, the copper content in the grain makes it impossible to recommend the cultivation of this crop in soil contaminated with this metal.