Division of Life Sciences and Medicine, Division of Molecular & Cell Biophysics, Hefei National Science Center for Interdisciplinary Sciences at the Microscale, MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, University of Science and Technology of China, The Innovation Academy of Seed Design, Chinese Academy of Sciences, Hefei, Anhui Province 230027, China.
School of Agronomy, Anhui Agricultural University, Hefei, Anhui Province 230036, China.
Mol Plant. 2023 Oct 2;16(10):1661-1677. doi: 10.1016/j.molp.2023.09.004. Epub 2023 Sep 9.
Crop yield plays a critical role in global food security. For optimal plant growth and maximal crop yields, nutrients must be balanced. However, the potential significance of balanced nitrogen-iron (N-Fe) for improving crop yield and nitrogen use efficiency (NUE) has not previously been addressed. Here, we show that balanced N-Fe sufficiency significantly increases tiller number and boosts yield and NUE in rice and wheat. NIN-like protein 4 (OsNLP4) plays a pivotal role in maintaining the N-Fe balance by coordinately regulating the expression of multiple genes involved in N and Fe metabolism and signaling. OsNLP4 also suppresses OsD3 expression and strigolactone (SL) signaling, thereby promoting tillering. Balanced N-Fe sufficiency promotes the nuclear localization of OsNLP4 by reducing HO levels, reinforcing the functions of OsNLP4. Interestingly, we found that OsNLP4 upregulates the expression of a set of HO-scavenging genes to promote its own accumulation in the nucleus. Furthermore, we demonstrated that foliar spraying of balanced N-Fe fertilizer at the tillering stage can effectively increase tiller number, yield, and NUE of both rice and wheat in the field. Collectively, these findings reveal the previously unrecognized effects of N-Fe balance on grain yield and NUE as well as the molecular mechanism by which the OsNLP4-OsD3 module integrates N-Fe nutrient signals to downregulate SL signaling and thereby promote rice tillering. Our study sheds light on how N-Fe nutrient signals modulate rice tillering and provide potential innovative approaches that improve crop yield with reduced N fertilizer input for benefitting sustainable agriculture worldwide.
作物产量对全球粮食安全起着至关重要的作用。为了实现植物的最佳生长和最大产量，养分必须保持平衡。然而，平衡氮铁（N-Fe）对提高作物产量和氮利用效率（NUE）的潜在重要性尚未得到解决。在这里，我们表明，平衡的 N-Fe 充足显著增加分蘖数，并提高水稻和小麦的产量和 NUE。NIN 样蛋白 4（OsNLP4）通过协调调节多个参与 N 和 Fe 代谢和信号转导的基因的表达，在维持 N-Fe 平衡方面发挥着关键作用。OsNLP4 还抑制 OsD3 的表达和独脚金内酯（SL）信号转导，从而促进分蘖。平衡的 N-Fe 充足通过降低 HO 水平促进 OsNLP4 的核定位，从而增强 OsNLP4 的功能。有趣的是，我们发现 OsNLP4 上调一组 HO 清除基因的表达，以促进其自身在核内的积累。此外，我们证明在分蘖期叶面喷施平衡的 N-Fe 肥料可以有效地增加水稻和小麦在田间的分蘖数、产量和 NUE。总的来说，这些发现揭示了 N-Fe 平衡对谷物产量和 NUE 的以前未被认识的影响，以及 OsNLP4-OsD3 模块整合 N-Fe 营养信号以下调 SL 信号转导从而促进水稻分蘖的分子机制。我们的研究阐明了 N-Fe 营养信号如何调节水稻分蘖，并为减少氮肥投入提高作物产量提供了潜在的创新方法，有利于全球可持续农业。
