Deciphering the Impact of Nitrogen Morphologies Distribution on Nitrogen and Biomass Accumulation in Tobacco Plants

Background and aimsNitrogen (N) distribution in plants is intricately linked to key physiological functions, including respiration, photosynthesis, structural development, and nitrogen storage. However, the specific effects of different N morphologies on N accumulation and plant growth are poorly understood. Our research specifically focused on determining how different N morphologies affect N absorption and biomass accumulation.MethodsThis study elucidated the impact of different application rates (CK: 0 g N/plant; T1: 4 g N/plant; T2: 8 g N/plant) of N fertilizer on N and biomass accumulation in tobacco cultivars Hongda and K326 at different growth stages.ResultsOur findings emphasize the critical role of N distribution in various plant parts, including leaves, stems, and roots, in determining the complex mechanisms of N and biomass accumulation in tobacco. We found that in relation to total N, a greater ratio of water-soluble N (Nw) in leaves facilitated N accumulation in leaves. In contrast, an increased ratio of SDS (detergent)-insoluble N (Nin-SDS) in leaves and non-protein N (Nnp) in roots hindered this increase. Additionally, our results indicate that a greater proportion of Nnp in leaves has a negative impact on biomass accumulation in leaves. Furthermore, elevated levels of Nin-SDS, Nw, and Nnp in roots, and Nnp in leaves adversely affected biomass accumulation in tobacco leaves. The Hongda cultivar exhibited greater biomass and N accumulation abilities as compared to K326.ConclusionsOur findings highlight the significant role of distribution of N morphologies on plant growth, as well as N and biomass accumulation in tobacco plants. Understanding N distribution allows farmers to optimize N application, minimizing environmental losses and maximizing yield for specific cultivars. These insights advance sustainable agriculture by promoting efficient resource use and reducing environmental impact.