Citrus responses to nitrate/ammonium uptake and maintenance of plant electrochemical balance

• Grant number: 25/02230-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: April 01, 2025
• End date: May 31, 2028
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Dirceu de Mattos Junior
• Grantee: Gabriel Antonio Bortoloti
• Host Institution: Instituto Agronômico (IAC). Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). Campinas , SP, Brazil
• Associated research grant: 24/00985-1 - Smart B100 Advanced Research Center (CCD-SB100), AP.CCD

Abstract

The citrus industry plays a prominent role in the Brazilian economy due to the size of the production areas and the value of the product in both the domestic and export markets, whose yields are largely regulated by the supply of nitrogen (N). N additions via fertilization in citrus groves typically range from 160 to 240 kg ha-1 year-1, which justifies the need for maintenance and/or significant gains in the efficiency of nutrient use, especially in new agricultural scenarios that seek greater increases in productivity. Given the intrinsic characteristics of citrus in N absorption (responsive to NO3- : NH4+ ratios), in the electrochemical balance of the plant, and the differential absorption of other ions, a study will be carried out with young orange plants of the factorial type, grown in nutrient solution with different ratios of N in the nitric and ammoniacal form. The total carbohydrate content, antioxidant enzyme activity, free amino acids, nitrate reductase activity, nutrient absorption, modulation of H+-ATPase activity of the plasma membrane in the roots, balance of cations and anions absorbed by the plants, and growth parameters will be evaluated. The results of this research will allow the characterization of plant responses to nitrogen nutrition and interactions with other nutrients that will contribute to better fertilization management and increase the efficiency of nutrient use in agriculture.