结论:过表达OsNRT1.1A可促进缺氮条件下小麦的早期抽穗并提高其耐受性。无机氮(N)肥的施用是作物产量进步的主要动力。然而,化肥的过度使用大大增加了生产成本并导致环境问题,为了可持续农业,提高作物氮素利用效率(NUE)至关重要。在这项研究中,我们创建了一系列携带水稻OsNRT1.1A基因的转基因小麦品系,编码硝酸盐转运蛋白,探讨其在提高小麦NUE中的可能应用。转基因小麦表现出早期成熟等性状,与拟南芥和水稻中OsNRT1.1A的过表达高度一致。然而,我们还观察到OsNRT1.1A基因在小麦中的过表达可以在低氮条件下促进根系的生长,但在正常氮条件下对生长发育的其他方面没有影响。因此,这可能导致小麦耐低氮能力的提高,这与其他植物报道的效果不同。田间试验分析表明,在低氮条件下,转基因小麦的单株籽粒产量增加。此外,转录组分析表明,OsNRT1.1A增加了小麦氮素吸收和利用基因的表达水平,从而促进植物在低氮条件下的生长。一起来看,我们的结果表明,OsNRT1.1A在提高氮利用率低的小麦的NUE中起着重要作用。
CONCLUSIONS: Overexpression of OsNRT1.1A promotes early heading and increases the tolerance in wheat under nitrogen deficiency conditions. The application of inorganic nitrogen (N) fertilizers is a major driving force for crop yield improvement. However, the overuse of fertilizers significantly raises production costs and leads to environmental problems, making it critical to enhance crop nitrogen use efficiency (NUE) for the sake of sustainable agriculture. In this study, we created a series of transgenic wheat lines carrying the rice OsNRT1.1A gene, which encodes a nitrate transporter, to investigate its possible application in improving NUE in wheat. The transgenic wheat exhibited traits such as early maturation that were highly consistent with the overexpression of OsNRT1.1A in Arabidopsis and rice. However, we also observed that overexpression of the OsNRT1.1A gene in wheat can facilitate the growth of roots under low N conditions but has no effect on other aspects of growth and development under normal N conditions. Thus, it may lead to the improvement of wheat low N tolerance,which is different from the effects reported in other plants. A field trial analysis showed that transgenic wheat exhibited increased grain yield per plant under low N conditions. Moreover, transcriptome analysis indicated that OsNRT1.1A increased the expression levels of N uptake and utilization genes in wheat, thereby promoting plant growth under low N conditions. Taken together, our results indicated that OsNRT1.1A plays an important role in improving NUE in wheat with low N availability.