Abstract：
Soil salinity poses a substantial threat to agricultural productivity, resulting in far-reaching consequences. Green-synthesized lignin nanoparticles (LNPs) have emerged as significant biopolymers which effectively promote sustainable crop production and enhance abiotic stress tolerance. However, the defensive role and underlying mechanisms of LNPs against salt stress in Zea mays remain unexplored. The present study aims to elucidate two aspects: firstly, the synthesis of lignin nanoparticles from alkali lignin, which were characterized using Field Emission Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy (TEM), Fourier Infrared Spectroscopy (FT-IR) and Energy Dispersive X-Ray Spectroscopy (EDX). The results confirmed the purity and morphology of LNPs. Secondly, the utilization of LNPs (200 mg/L) in nano priming to alleviate the adverse effects of NaCl (150 mM) on Zea mays seedlings. LNPs significantly reduced the accumulation of Na+ (17/21%) and MDA levels (21/28%) in shoots/roots while increased lignin absorption (30/31%), resulting in improved photosynthetic performance and plant growth. Moreover, LNPs substantially improved plant biomass, antioxidant enzymatic activities and upregulated the expression of salt-tolerant genes (ZmNHX3 (1.52 & 2.81 FC), CBL (2.83 & 3.28 FC), ZmHKT1 (2.09 & 4.87 FC) and MAPK1 (3.50 & 2.39 FC) in both shoot and root tissues. Additionally, SEM and TEM observations of plant tissues confirmed the pivotal role of LNPs in mitigating NaCl-induced stress by reducing damages to guard cells, stomata and ultra-cellular structures. Overall, our findings highlight the efficacy of LNPs as a practical and cost-effective approach to alleviate NaCl-induced stress in Zea mays plants. These results offer a sustainable agri-environmental strategy for mitigating salt toxicity and enhancing crop production in saline environments.
摘要：
土壤盐分对农业生产力构成重大威胁,造成了深远的后果。绿色合成的木质素纳米颗粒（LNP）已成为重要的生物聚合物，可有效促进作物的可持续生产并增强非生物胁迫耐受性。然而,LNPs对玉米盐胁迫的防御作用和潜在机制仍未被探索。本研究旨在阐明两个方面：首先，从碱木质素合成木质素纳米颗粒，使用场发射扫描电子显微镜(FE-SEM)对其进行表征，透射电子显微镜(TEM),傅里叶红外光谱(FT-IR)和能量色散X射线光谱(EDX)。结果证实了LNP的纯度和形态。其次,在纳米引发中利用LNPs（200mg/L）来减轻NaCl（150mM）对玉米幼苗的不利影响。LNP显着降低了芽/根中Na（17/21％）和MDA水平（21/28％）的积累，同时增加了木质素的吸收（30/31％），从而改善光合性能和植物生长。此外，LNP大幅提高了植物生物量，抗氧化酶活性并上调耐盐基因的表达(ZmNHX3(1.52&2.81FC)，CBL（2.83和3.28FC），茎和根组织中的ZmHKT1（2.09和4.87FC）和MAPK1（3.50和2.39FC）。此外,植物组织的SEM和TEM观察证实了LNP在减轻NaCl诱导的胁迫中的关键作用，通过减少对保卫细胞的损伤，气孔和超细胞结构。总的来说,我们的发现强调了LNPs作为一种实用且具有成本效益的方法来缓解玉米植物中NaCl诱导的胁迫的功效。这些结果提供了可持续的农业环境策略，以减轻盐毒性并提高盐碱环境中的作物产量。
