Nguyen The Ngoc Phuong, Serwaa Rose Nimoh, Sung Jwakyung
Department of Crop Science, College of Agriculture, Life and Environment Sciences, Chungbuk National University, Cheongju 28644, Republic of Korea.
Metabolites. 2025 Aug 1;15(8):519. doi: 10.3390/metabo15080519.
: Nitrogen (N) is an essential macronutrient that strongly influences maize growth and metabolism. While many studies have focused on nitrogen responses during later developmental stages, early-stage physiological and metabolic responses remain less explored. This study investigated the effect of different nitrogen-deficient levels on maize seedling growth and primary metabolite profiles. : Seedlings were treated with N-modified nutrient solution, which contained 0% to 120% of the standard nitrogen level (8.5 mM). : Nitrogen starvation (N0) significantly reduced plant height (by 11-14%), shoot fresh weight (over 30%) compared to the optimal N supply (N100). Total leaf nitrogen content under N0-N20 was less than half of that in N100, whereas moderate N deficiency resulted in moderate reductions in growth and nitrogen content. Metabolite analysis revealed that N deficiency induced the accumulation of soluble sugars and organic acids (up to threefold), while sufficient N promoted the synthesis of amino acids related to nitrogen assimilation and protein biosynthesis. Statistical analyses (PCA and ANOVA) showed that both genotypes (MB and TYC) and tissue type (upper vs. lower leaves) influenced the metabolic response to nitrogen, with MB displaying more consistent shifts and TYC exhibiting greater variability under moderate stress. : These findings highlight the sensitivity of maize seedlings to early nitrogen deficiency, with severity influenced by nitrogen level, tissue-specific position, and genotype; thus underscore the close coordination between physiological growth and primary metabolic pathways in response to nitrogen availability. These findings expand current knowledge of nitrogen response mechanisms and offer practical insights for improving nitrogen use efficiency in maize cultivation.
氮（N）是一种必需的大量营养素，对玉米的生长和代谢有强烈影响。虽然许多研究集中在后期发育阶段的氮响应，但早期的生理和代谢响应仍较少被探索。本研究调查了不同缺氮水平对玉米幼苗生长和主要代谢物谱的影响。：用氮改良营养液处理幼苗，该营养液含有标准氮水平（8.5 mM）的0%至120%。：与最佳氮供应（N100）相比，氮饥饿（N0）显著降低了株高（11%-14%）、地上部鲜重（超过30%）。N0-N20条件下的总叶片氮含量不到N100的一半，而中度缺氮导致生长和氮含量适度降低。代谢物分析表明，缺氮诱导了可溶性糖和有机酸的积累（高达三倍），而充足的氮促进了与氮同化和蛋白质生物合成相关的氨基酸的合成。统计分析（主成分分析和方差分析）表明，基因型（MB和TYC）和组织类型（上部叶片与下部叶片）均影响对氮的代谢响应，在中度胁迫下，MB表现出更一致的变化，而TYC表现出更大的变异性。：这些发现突出了玉米幼苗对早期缺氮的敏感性，其严重程度受氮水平、组织特异性位置和基因型的影响；因此强调了生理生长与初级代谢途径之间在响应氮有效性方面的密切协调。这些发现扩展了当前对氮响应机制的认识，并为提高玉米种植中的氮利用效率提供了实际见解。
