Yang Xu, Alsherif Emad A, El-Shafey Nadia Mohamed, Korany Shereen Magdy, Alhaj Hamoud Yousef, Shaghaleh Hiba, Sheteiwy Mohamed S, Ulhassan Zaid, Madany Mahmoud M Y
College of Hydrology and Water Resources, Hohai University, Nanjing, Jiangsu, 210024, China; China Meteorological Administration Hydro-Meteorology Key Laboratory, Hohai University, Nanjing, Jiangsu, 210024, China.
Department of Botany and Microbiology, Faculty of Science, Beni-Suef University, Beni-Suef, 62511, Egypt.
Plant Physiol Biochem. 2025 Jul 7;228:110220. doi: 10.1016/j.plaphy.2025.110220.
Bismuth (Bi) stress significantly challenges plant growth, yield, and metabolism. Thus, this study investigated how arbuscular mycorrhizal fungi (AMF) and Germanium (Ge), and their interactions, could mitigate bismuth (Bi) stress on rye yield and metabolism. Our findings show that AMF and Ge, both individually and combined, enhance plant resilience under Bi stress by improving primary and secondary metabolic pathways. Bi stress significantly reduced seed yield. However, AMF and Ge treatments alleviated this, yielding the highest recovery. This improved yield was linked to enhanced metabolic efficiency, specifically through increased sugar availability. This provided an accessible carbon source, supporting key primary metabolic processes like organic acids, nitrogen assimilation, amino acids, and fatty acids. The study found organic acids, including oxalic, citric, and succinic acids, increased under AMF, Ge, and Bi stress. Bi stress also raised key fatty acid levels, likely a defense response, while AMF and Ge modified these concentrations, suggesting roles in lipid metabolism. Amino acid profiling showed Bi stress caused stress-responsive amino acid accumulation. AMF and Ge treatments modulated these, notably reducing isoleucine under Bi stress. Furthermore, essential amino acids like arginine and glutathione were pivotal in regulating polyamine metabolism, crucial for stress adaptation and cellular stability. Polyamine analysis revealed AMF and Ge treatments caused the highest polyamine accumulation in unstressed plants, with S-adenosyl-L-methionine showing the most enhancement. Under Bi stress, polyamine levels generally increased as part of the defense. However, the combined AMF, Ge, and Bi treatment resulted in a decline, suggesting a regulatory effect preventing excessive accumulation. Overall, these findings highlight the synergistic role of AMF and Ge in improving rye resilience to Bi stress. The observed improvements in sugar-mediated carbon flux, amino acid and polyamine metabolism, and secondary metabolite production collectively contributed to higher yield and stress adaptation. Future research should optimize AMF and Ge applications for stress management and crop improvement.
铋（Bi）胁迫对植物生长、产量和代谢构成重大挑战。因此，本研究调查了丛枝菌根真菌（AMF）和锗（Ge）及其相互作用如何减轻铋（Bi）胁迫对黑麦产量和代谢的影响。我们的研究结果表明，AMF和Ge单独或联合使用，均可通过改善初级和次级代谢途径增强植物在Bi胁迫下的恢复力。Bi胁迫显著降低了种子产量。然而，AMF和Ge处理减轻了这种影响，实现了最高的产量恢复。产量的提高与代谢效率的增强有关，特别是通过增加糖的可用性。这提供了一个可利用的碳源，支持了关键的初级代谢过程，如有机酸、氮同化、氨基酸和脂肪酸。研究发现，在AMF、Ge和Bi胁迫下，包括草酸、柠檬酸和琥珀酸在内的有机酸增加。Bi胁迫还提高了关键脂肪酸水平，这可能是一种防御反应，而AMF和Ge改变了这些浓度，表明它们在脂质代谢中发挥作用。氨基酸分析表明，Bi胁迫导致应激反应性氨基酸积累。AMF和Ge处理调节了这些氨基酸，特别是在Bi胁迫下显著降低了异亮氨酸含量。此外，精氨酸和谷胱甘肽等必需氨基酸在调节多胺代谢中起关键作用，多胺代谢对胁迫适应和细胞稳定性至关重要。多胺分析显示，AMF和Ge处理使未受胁迫植物中的多胺积累量最高，其中S-腺苷-L-甲硫氨酸的增加最为显著。在Bi胁迫下，多胺水平通常作为防御反应的一部分而增加。然而，AMF、Ge和Bi联合处理导致多胺水平下降，表明存在一种调节作用，可防止多胺过度积累。总体而言，这些发现突出了AMF和Ge在提高黑麦对Bi胁迫恢复力方面的协同作用。观察到的糖介导的碳通量、氨基酸和多胺代谢以及次级代谢产物产量的改善共同促成了更高的产量和胁迫适应能力。未来的研究应优化AMF和Ge的应用，以进行胁迫管理和作物改良。
