Li Zi, Li Zhuangyan, Lu Yifei, Ren Bi, Zeng Fuchun, Yang Shimin, Lu Liming, Li Liqin
College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China.
Int J Mol Sci. 2025 May 4;26(9):4374. doi: 10.3390/ijms26094374.
Nitrogen is an important nutrient required for plant growth and development, but most of the time plants face nitrogen deficiency, all it is important to study the mechanism of low nitrogen tolerance in plants. This study addresses this gap by investigating the role of the gene through the generation and analysis of transgenic potato lines overexpressing (OE1, OE2, OE3). Exogenous BL treatment showed that the gene responded to oleuropein lactone. Phenotypic assessments under normal nitrogen (NN) and low nitrogen (LN) conditions demonstrated that OE2 consistently outperformed WT, showing a 43% increase in root vitality and a 23% retention of chlorophyll under LN. Additionally, OE2 transgenics accumulated significantly higher levels of nitrate nitrogen (64.1% increase) and ammonium nitrogen (53% increase) compared to WT. Enzymatic assays further confirmed elevated activities of glutamine synthetase and nitrate reductase in both OE1 and OE2 lines. Hormone analyses showed that BL content of overexpression lines was significantly increased under LN conditions, higher Oleandrin lactone (BL) content of OE2 improved plant stress tolerance, and WT was more affected by low nitrogen stress than OE2, resulting in higher levels of stress hormones than OE2. Temporal gene expression analysis showed significant upregulation of key nitrogen metabolism-related genes (, , , ) in OE2, with expression reaching 79% higher than WT at 3 h. Protein-protein interaction assays, including yeast two-hybrid and BiLC assays, verified the interaction between and , suggesting the existence of a functional network to enhance low-nitrogen tolerance in potato plants. In conclusion, these findings suggest that overexpression of significantly enhances low-nitrogen tolerance in transgenic potato lines, providing a promising strategy for improving crop performance under nitrogen-limited conditions.
氮是植物生长发育所需的重要养分，但大多数时候植物面临氮素缺乏的情况，因此研究植物耐低氮机制非常重要。本研究通过构建过表达该基因的转基因马铃薯株系（OE1、OE2、OE3）并进行分析，填补了这一空白。外源油菜素内酯（BL）处理表明该基因对橄榄苦苷内酯有响应。在正常氮（NN）和低氮（LN）条件下的表型评估表明，OE2始终优于野生型（WT），在低氮条件下根系活力提高了43%，叶绿素保留率提高了23%。此外，与野生型相比，OE2转基因株系积累的硝态氮（增加64.1%）和铵态氮（增加53%）水平显著更高。酶活性分析进一步证实OE1和OE2株系中谷氨酰胺合成酶和硝酸还原酶的活性升高。激素分析表明，在低氮条件下过表达株系的油菜素内酯含量显著增加，OE2中较高的橄榄苦苷内酯（BL）含量提高了植物的胁迫耐受性，野生型比OE2更易受到低氮胁迫的影响，导致其胁迫激素水平高于OE2。时间基因表达分析表明，OE2中关键氮代谢相关基因（、、、）显著上调，在3小时时表达量比野生型高79%。包括酵母双杂交和双分子荧光互补（BiLC）分析在内的蛋白质-蛋白质相互作用分析验证了与之间的相互作用，表明存在一个增强马铃薯植株耐低氮能力的功能网络。总之，这些发现表明该基因的过表达显著增强了转基因马铃薯株系的耐低氮能力，为改善氮素限制条件下的作物性能提供了一种有前景的策略。
