Abstract：
Cadmium (Cd) contamination in agricultural soil is a major global concern among the multitude of human health and food security. Zinc oxide nanoparticles (ZnO-NPs) and plant growth promoting rhizobacteria (PGPR) have been known to combat heavy metal toxicity in crops. Herein, the study intended to explore the interactive effect of treatments mediated by inoculation of PGPR and foliar applied ZnO-NPs to alleviate Cd induced phytotoxicity in wheat plants which is rarely investigated. For this purpose, TaEIL1 expression, morpho-physiological, and biochemical traits of wheat were examined. Our results revealed that Cd reduced growth and biomass, disrupted plant physiological and biochemical traits, and further expression patterns of TaEIL1. The foliar application of ZnO-NPs improved growth attributes, photosynthetic pigments, and gas exchange parameters in a dose-additive manner, and this effect was further amplified with a combination of PGPR. The combined application of ZnO-NPs (100 mg L-1) with PGPR considerably increased the catalase (CAT; 52.4%), peroxidase (POD; 57.4%), superoxide dismutase (SOD; 60.1%), ascorbate peroxidase (APX; 47.4%), leading to decreased malondialdehyde (MDA; 47.4%), hydrogen peroxide (H2O2; 38.2%) and electrolyte leakage (EL; 47.3%) under high Cd (20 mg kg-1) stress. Furthermore, results revealed a significant reduction in roots (56.3%), shoots (49.4%), and grains (59.4%) Cd concentration after the Combined treatment of ZnO-NPs and PGPR as compared to the control. Relative expression of TaEIL1 (two homologues) was evaluated under control (Cd 0), Cd, ZnO-NPs, PGPR, and combined treatments. Expression profiling revealed a differential expression pattern of TaEIL1 under different treatments. The expression pattern of TaEIL1 genes was upregulated under Cd stress but downregulated under combined ZnO-NPs and PGPR, revealing its crucial role in Cd stress tolerance. Inferentially, ZnO-NPs and PGPR showed significant potential to alleviate Cd toxicity in wheat by modulating the antioxidant defense system and TaEIL1 expression. By inhibiting Cd uptake, and facilitating their detoxification, this innovative approach ensures food safety and security.
摘要：
农业土壤中的镉（Cd）污染是全球众多人类健康和粮食安全关注的主要问题。已知氧化锌纳米颗粒（ZnO-NP）和植物生长促进根际细菌（PGPR）可以对抗作物中的重金属毒性。在这里，该研究旨在探索通过接种PGPR和叶面施用的ZnO-NPs介导的处理的相互作用效应，以减轻小麦植株中Cd引起的植物毒性，这很少被研究。为此,TaEIL1表达，形态生理，并对小麦的生化性状进行了检测。我们的结果表明，Cd降低了生长和生物量，破坏植物生理和生化特性，以及TaEIL1的进一步表达模式。ZnO-NP的叶面施用改善了生长属性，光合色素,和气体交换参数以剂量相加的方式，PGPR的组合进一步放大了这种效应。ZnO-NP（100mgL-1）与PGPR的联合应用显着增加了过氧化氢酶（CAT；52.4％），过氧化物酶(POD;57.4%),超氧化物歧化酶(SOD;60.1%),抗坏血酸过氧化物酶(APX;47.4%),导致丙二醛（MDA；47.4%）减少，在高Cd（20mgkg-1）胁迫下，过氧化氢（H2O2；38.2％）和电解质泄漏（EL；47.3％）。此外，结果显示根系显著减少(56.3%)，射击（49.4％），与对照相比，ZnO-NP和PGPR的联合处理后的晶粒（59.4％）Cd浓度。在对照（Cd0）下评估TaEIL1（两个同源物）的相对表达，Cd,ZnO-NP,PGPR,和联合治疗。表达谱揭示了TaEIL1在不同处理下的差异表达模式。TaEIL1基因在Cd胁迫下表达上调，而在ZnO-NPs和PGPR联合下表达下调，揭示了其在镉胁迫耐受性中的关键作用。Inference,ZnO-NPs和PGPR显示出通过调节抗氧化防御系统和TaEIL1表达来减轻小麦中Cd毒性的显着潜力。通过抑制Cd的吸收，促进他们的戒毒，这种创新方法确保了食品安全。
