Rice is highly susceptible to salt stress. Increasing the salt tolerance of rice is critical to reduce yield loss. Herein, we investigated the possibility of using an AgNP-based priming method (seed soaking (SP) and leaf spraying (LP)) to enhance rice salt tolerance. Under saline conditions, both SP (40 mg L⁻¹) and LP (∼0.15 mg per plant) significantly increased the biomass (10.4–13.4%) and height (6.6–6.9%) of 6-week-old rice seedlings. In addition, SP significantly increased chlorophyll a (7.3%) and carotenoid (7.9%) content as well as total antioxidant capacity (10.5%), whereas it decreased malondialdehyde (MDA) content (16.9%) in rice leaves. These findings indicate that AgNP priming, especially SP, improved the salt tolerance of rice seedlings. A life cycle field study conducted in a real saline land revealed that SP significantly increased the rice grain yield by 25.8% compared to hydropriming. Multi-omics analyses demonstrated that AgNP priming induced metabolic and transcriptional reprogramming in both seeds and leaves. Notably, both SP and LP upregulated osmoprotectants in seeds and leaves. Furthermore, several transcriptional factors (TFs), such as WRKY and NAC, and salt-tolerance related genes, including the high-affinity K⁺ channel gene (OsHKT2;4, OsHAK5), the Ca²⁺/proton exchanger (CAX4), and the cation/Ca²⁺ exchanger (CCX4), were upregulated in leaves. Omics data provide a deep insight into the molecular mechanisms for enhanced salinity tolerance. Together, the results of this study suggest that seed priming with AgNPs can enhance the salt tolerance of rice and increase rice yield in saline soil, which provides an efficient and simple way to engineering salt-tolerant rice.

中文翻译：

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多组学揭示了 AgNP 引发增强水稻耐盐性的机制


水稻极易受到盐胁迫的影响。提高水稻的耐盐性对于减少产量损失至关重要。在此，我们研究了使用基于 AgNP 的引发方法 （种子浸泡 （SP） 和叶片喷洒 （LP）） 来提高稻盐耐受性的可能性。在盐碱条件下，SP （40 mg ^L-1） 和 LP （每株∼0.15 mg） 均显著增加了 6 周龄水稻幼苗的生物量 （10.4-13.4%） 和高度 （6.6-6.9%）。此外，SP 显著提高了水稻叶片中叶绿素 a （7.3%） 和类胡萝卜素 （7.9%） 的含量以及总抗氧化能力 （10.5%），同时降低了丙二醛 （MDA） 的含量 （16.9%）。这些结果表明，AgNP 引发，尤其是 SP，提高了水稻幼苗的耐盐性。在真实盐碱地进行的一项生命周期田间研究表明，与加氢引发相比，SP 显着提高了 25.8% 的水稻产量。多组学分析表明，AgNP 引发诱导种子和叶片的代谢和转录重编程。值得注意的是，SP 和 LP 都上调了种子和叶中的渗透保护剂。此外，几种转录因子 （TF），如 WRKY 和 NAC，以及耐盐相关基因，包括高亲和力 K⁺ 通道基因 （OsHKT2;4， OsHAK5）、Ca²⁺/质子交换蛋白 （CAX4） 和阳离子/Ca²⁺ 交换蛋白 （CCX4） 在叶片中上调。组学数据为增强耐盐性的分子机制提供了深入的见解。 总之，本研究的结果表明，用 AgNPs 引发种子可以提高水稻的耐盐性，提高水稻在盐渍土壤中的产量，这为工程耐盐水稻提供了一种有效而简单的方法。