Changes in Metabolic Profile of Rice Leaves Induced by Humic Acids

Abstract

The use of humic substances in agriculture as a biostimulant emerged as one of the promising methods to promote sustainable production. Different molecular, biochemical, and physiological processes are triggered, resulting in nutrient efficiency use and protection against abiotic stress. Understanding plant changes promoted by humic substances is essential for innovative and tailored biostimulation technologies. Cell metabolites are the final target of the response chain, and the metabolomic approach can be helpful in unveiling pathways related to plant response. This study aimed to evaluate a global metabolic alteration of rice leaves induced by humic acids (HA) applied in a hydroponics system. Using 1H NMR and GC-TOF/MS analysis, we observed a significant decrease in all main metabolites classes in leaves treated with HA, including lipids, organic acids, amino acids, and carbohydrates. Metabolites in higher concentrations in HA-treated plants are candidates as markers of HA bioactivity, including amino acids, intermediates of tricarboxylic acid cycle, and lipids, and aromatic compounds related to plant-stress response.

Evaluation of Sustainable Recycled Products to Increase the Production of Nutraceutical and Antibacterial Molecules in Basil Plants by a Combined Metabolomic Approach

“…Therefore, an increasing focus is devoted to sustainable approaches to promote the synthesis of secondary metabolites in aromatic plants thereby preserving the quality of the final products [ 11 ]. In this context, the natural organic fraction obtained from recycled biomasses, such as humic substances (HS) and compost teas (CTs) have been identified as valuable potential abiotic effectors or biostimulants due to their ability to influence directly and indirectly the plant metabolism [ 12 , 13 ]. These molecules can act as bioactive compounds or bioeffectors in various physiological processes, including nutrient up-take, ion transport, enzyme activities, and stress resilience, by promoting appraisable effects on biochemical reactions of primary and secondary metabolism, connected to antibacterial or antioxidant activity and anti-inflammatory action [ 14 , 15 , 16 ].…”