Morphophysiological and biochemical responses involved in nitrogen and sugar metabolism in sugarcane varieties fertilized with selenium

Author(s)

Maycon Anderson de Araujo

• Document type: Master's Dissertation
• Press: Ilha Solteira. 2022-04-08.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Engenharia. Ilha Solteira
• Defense date: 2022-02-11
• Advisor: André Rodrigues dos Reis

Abstract

Selenium (Se) is a beneficial element for plants and essential for humans and animals. The need for Se fertilization in cultivated plants is important in the face of climate changes such as increased atmospheric temperature and lower water availability, which induces greater abiotic stress. The beneficial effect of Se in plants is directly related to the promotion of nitrogen assimilation efficiency and its role as a mitigator of abiotic stress by reducing reactive oxygen species due to the promotion of antioxidant metabolism. The work is divided into four chapters. The first is characterized by a systematic review of the role of Se in plant metabolism. The second and third chapters correspond, respectively, to the analysis carried out at 45 and 85 after the application of the treatments. The fourth chapter brings the morphoanatomical changes in leaves and roots presented by sugarcane varieties after fertilization with Se. The objective of this study was to evaluate the effect of Se application on sugarcane, evaluating the morphophysiological and biochemical responses and relationships with growth and productivity. The experiment was carried out in a completely randomized design, with a factorial scheme, using two sugarcane varieties (RB96 6928 and RB86 7515) and 4 concentrations of Se (0; 5; 10 and 20 μmol L -1 ) applied in the form of sodium selenate in nutrient solution, distributed in four replications. Physiological evaluations were realized at 45 and 85 days after Se application, and anatomical assessments were performed at 60 days after application of treatments. Se concentration in sugarcane leaves increased with application of sodium selenate doses for both varieties, which showed different morphophysiological responses. From the analysis at 45 days and 85 days, it was possible to observe changes in nitrogen and carbohydrates metabolisms, pigments and photosynthetic rates, control of lipid peroxidation and antioxidative responses. Despite positive responses for both varieties in the other variables, only the RB96 6928 variety showed an increase in sucrose and total sugar concentrations in the juice. Regarding the morphoanatomy, the application of Se caused changes in the leaf and root anatomy of sugarcane varieties, changes that may help to increase tolerance to abiotic stress. Se application increased nitrogen and antioxidant metabolism of sugarcane varieties. This triggered the highest growth and productivity of both varieties. This study brings important relevant and original information about the applicability of Se fertilization in sugarcane. (AU)

• FAPESP's process: 20/06461-3 - Physiological and biochemical responses involved in metabolism of nitrogen and sugars in sugarcane varieties fertilized with selenium
• Grantee: Maycon Anderson de Araujo
• Support Opportunities: Scholarships in Brazil - Master