Key Lab of Bio-Organic Fertilizer Creation, Ministry of Agriculture , Anhui Science and Technology University , Bengbu 233100 , China.
Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-Saving Fertilizers , Nanjing Agricultural University , Nanjing 210095 , China.
J Agric Food Chem. 2019 Sep 11;67(36):10126-10136. doi: 10.1021/acs.jafc.9b03293. Epub 2019 Aug 30.
Soil microbes have recently been utilized to improve cadmium (Cd) tolerance and lower its accumulation in plants. Nevertheless, whether rhizobacteria can prevent Cd uptake by graminaceous plants and the underlying mechanisms remain elusive. In this study, inoculation with NC16 reduced transpiration rates and the expression of some iron (Fe) uptake-related genes including , , and in maize () plants, which contributed to mitigation of Cd toxicity. However, the inoculation with NC16 failed to suppress the transpiration rates and transcription of these Fe uptake-related genes in plants treated with fluridone, an abscisic acid (ABA) biosynthetic inhibitor, indicating that the impacts of NC16-inoculation observed were dependent on the actions of ABA. We found that NC16 increased the host ABA levels by mediating the metabolism of ABA rather than its synthesis. Moreover, the capacity of NC16 to inhibit plant uptake of Cd was greatly weakened in plants overexpressing Z, encoding a zinc/iron transporter. Collectively, our findings indicated that NC16 reduced Cd toxicity in maize plants at least partially by hampering the Fe uptake-associated pathways.
土壤微生物最近被用于提高镉（Cd）耐受性并降低其在植物中的积累。然而，根际细菌是否能防止禾本科植物吸收 Cd 以及其潜在的机制仍不清楚。在这项研究中，接种 NC16 降低了玉米（）植物的蒸腾速率和一些与铁（Fe）吸收相关基因的表达，包括 、 、 ，这有助于减轻 Cd 毒性。然而，在使用脱落酸（ABA）生物合成抑制剂氟啶酮处理的植物中，接种 NC16 未能抑制这些 Fe 吸收相关基因的蒸腾速率和转录，这表明 NC16 接种观察到的影响依赖于 ABA 的作用。我们发现 NC16 通过调节 ABA 的代谢而不是合成来增加宿主 ABA 水平。此外，在过表达编码锌/铁转运蛋白的 Z 的植物中，NC16 抑制植物吸收 Cd 的能力大大减弱。总之，我们的研究结果表明，NC16 通过阻碍与 Fe 吸收相关的途径至少部分降低了玉米植株的 Cd 毒性。
