Mobilização de compostos carbônicos e nitrogenados em plantas de milho sob desfolha e atuação do óxido nítrico na mitigação do estresse

Abstract

Agriculture faces challenges stemming from climate change and the depletion of natural resources, resulting in imbalances that impact plant growth, including corn. This crop is affected by environmental and biological factors such as defoliation, which reduces the photosynthetic area and hampers production. Plants possess stress detection and response mechanisms to restore their homeostasis, but the underlying metabolic processes following defoliation remain poorly understood. Nevertheless, these processes hold the potential to enhance crop yields as plant metabolism is highly adaptable to environmental changes. In this context, biostimulants like nitric oxide (NO) have been under investigation. Exogenous application of NO has shown to regulate redox balance and photosynthesis, mitigating adverse environmental stress effects on corn. This study aims to bridge knowledge gaps by investigating post-defoliation corn biochemistry and examining the potential of NO to alleviate detrimental defoliation effects and promote corn growth. The study focuses on gas exchange analysis, root morphology, and the levels of amino acids, sugars, and starch in both the aerial and root portions during plant recovery after defoliation with GSNO application. Results demonstrate that defoliation significantly affects primary metabolites by altering concentrations of amino acids, sugars, and starch. However, GSNO application as a biostimulant can mitigate these negative effects, promoting responses that benefit plant recovery post-defoliation. This suggests the potential of GSNO as a tool to enhance corn plant resilience to stress and foster healthier growth.