Sustainable management of iron (Fe) deficiency through the microbial association is highly desirable to ensure crop yield. This study elucidates whether and how arbuscular mycorrhizal fungi (AMF) ameliorate Fe deficiency symptoms in sorghum. AMF inoculation showed a significant improvement in plant biomass, chlorophyll score, Fv/Fm (quantum efficiency of photosystem II), and Pi_ABS (photosynthesis performance index), suggesting its potentiality to diminish Fe deficiency symptoms in sorghum. This AMF-driven prevention of Fe deficiency was further supported by the improvement of biochemical stress indicators, such as cell death, electrolyte leakage, hydrogen peroxide, and superoxide anion. In this study, AMF showed a significant increase in phytosiderophore (PS) release as well as Fe and S concentrations in sorghum under Fe deficiency. Quantitative real-time PCR analysis demonstrated the consistent upregulation of SbDMAS2 (deoxymugineic acid synthase 2), SbNAS2 (nicotianamine synthase 2), and SbYS1 (Fe-phytosiderophore transporter yellow stripe) in roots due to AMF with Fe deficiency. It suggests that the enhancement of Fe due to AMF is related to the mobilization of Fe(III)-PS in the rhizosphere supported by the long-distance transport of Fe by SbYS1 transporter in sorghum. Our study further showed that the elevation of S mainly in the presence of AMF possibly enhances the S-containing antioxidant metabolites (Met, Cys, and GSH) as well as enzymes (CAT, SOD, and GR) to counteract H 2 O 2 and O 2 − for the restoration of redox status in Fe-deprived sorghum. Moreover, S possibly participates in Strategy II responses revealing its crucial role as a signaling molecule for Fe homeostasis in sorghum.

中文翻译：

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丛枝菌根真菌通过植物铁载体介导的铁动员和氧化还原状态的恢复减轻高粱缺铁症状

通过微生物关联可持续管理铁 (Fe) 缺乏症对于确保作物产量非常必要。这项研究阐明了丛枝菌根真菌 (AMF) 是否以及如何改善高粱的缺铁症状。AMF 接种显示植物生物量、叶绿素评分、Fv/Fm（光系统 II 的量子效率）和 Pi_ABS（光合作用性能指数）有显着改善，表明其具有减轻高粱缺铁症状的潜力。这种由 AMF 驱动的 Fe 缺乏预防得到了生化应激指标的改善的进一步支持，如细胞死亡、电解质泄漏、过氧化氢和超氧阴离子。在这项研究中，AMF 显示出在缺铁条件下高粱中植物铁素 (PS) 释放以及 Fe 和 S 浓度显着增加。实时定量 PCR 分析表明，由于铁缺乏的 AMF，根中 SbDMAS2（脱氧麦根酸合酶 2）、SbNAS2（烟胺合酶 2）和 SbYS1（Fe-植物黄素转运蛋白黄色条纹）的一致上调。这表明 AMF 引起的 Fe 增强与高粱中 SbYS1 转运蛋白长距离运输 Fe 所支持的根际 Fe(III)-PS 的动员有关。我们的研究进一步表明，主要在 AMF 存在下 S 的升高可能会增强含 S 的抗氧化代谢物（Met、Cys 和 GSH）以及酶（CAT、SOD 和 GR）以抵消 H 2 O 2 和O 2 - 用于恢复缺铁高粱的氧化还原状态。而且，