Work

Nitrogen Form Substitution Enhances Growth and Carbon Accumulation in Maize

Year: 2025

Type: article

Abstract: Sugars are essential for plant development, and nitrogen (N) availability regulates their distribution, influencing overall growth. However, the mechanisms underlying carbon (C) assimilate allocation and utilization in response to changed N forms remain unclear. This study examined the effects of nitrogen form substitution (NFS) on C accumulation and utilization in hydroponically grown inbred mini-maize (TX-40 J). Maize seedlings were divided into three treatment groups: T1 (1 mM NO₃⁻), T2 (1 mM NH₄⁺), and T3, where 1 mM NO₃⁻ was substituted with 1 mM NH₄⁺ (NFS) at 10 days after seedling transfer (DAT). The results showed that NFS led to a significant (P≤0.05) reduction in total sucrolytic activity by 27% in leaves and 21% in roots, resulting in a lower hexose-to-sucrose ratio. Despite this, NFS enhanced shoot biomass by 30%, root biomass by 24%, and total biomass by 28%, suggesting improved sucrose utilization and increased competition for assimilates. Root-to-shoot biomass allocation was particularly enhanced under NFS conditions. Additionally, starch and sucrose accumulated at lower levels in leaves under NFS compared to other N treatments. Starch was predominantly stored in the leaf tips, whereas sucrose accumulated in the leaf sheath. This spatial sucrose and starch distribution suggests that C buildup was not due to impaired C assimilation but rather inefficient C utilization in sink tissues. These findings provide new insights into how NFS influences C allocation between leaves and roots, promoting growth and stress adaptation in maize. Understanding the role of C partitioning under NFS conditions may help optimize plant growth and improve nutrient use efficiency under N deficiency conditions.

Source: Journal of Plant Growth Regulation

DOI: 10.1007/s00344-025-11713-8

Authors: Joseph N. Amoah, Brent N. Kaiser

Institution: The University of Sydney

Language: English

Topic: Plant nutrient uptake and metabolism

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: hybrid

Estimated APC paid: $3,890