State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, No. 1 Shizishan Street, Hongshan District, Wuhan, 430070, Hubei, China.
State Key Laboratory of Agricultural Microbiology, College of Science, Huazhong Agricultural University, No. 1 Shizishan Street, Hongshan District, Wuhan, 430070, Hubei, China.
J Nanobiotechnology. 2022 Mar 31;20(1):168. doi: 10.1186/s12951-022-01372-2.
The study of symbiotic nitrogen fixation between (SNF) legumes and rhizobia has always been a hot frontier in scientific research. Nanotechnology provides a new strategy for biological nitrogen fixation research. However, how to construct abiotic nano-structure-biological system, using the special properties of nanomaterials, to realize the self-enhancement of biological nitrogen fixation capacity is important.
In order to construct a more efficient SNF system, in this study, we applied manganese ferrite nanoparticles (MF-NPs) with sustainable diatomic catalysis to produce reactive oxygen species (ROS), thus regulating the nodulation pathway and increasing the number of nodules in soybean (Glycine max), eventually enhancing symbiotic nitrogen fixation. Symbiosis cultivation of MF-NPs and soybean plants resulted in 50.85% and 61.4% increase in nodule weight and number, respectively, thus inducing a 151.36% nitrogen fixation efficiency increase, finally leading to a 25.70% biomass accumulation increase despite no substantial effect on the nitrogenase activity per unit. Transcriptome sequencing analysis showed that of 36 differentially expressed genes (DEGs), 31 DEGs related to soybean nodulation were upregulated in late rhizobium inoculation stage (12 d), indicating that the increase of nodules was derived from nodule-related genes (Nod-R) continuous inductions by MF-NPs.
Our results indicated that the nodule number could be effectively increased by extending the nodulation period without threatening the vegetative growth of plants or triggering the autoregulation of nodulation (AON) pathway. This study provides an effective strategy for induction of super-conventional nodulation.
共生固氮（SNF）豆科植物与根瘤菌的研究一直是科学研究的热点前沿。纳米技术为生物固氮研究提供了新的策略。然而，如何构建非生物纳米结构-生物系统，利用纳米材料的特殊性质，实现生物固氮能力的自我增强，是一个重要的问题。
为了构建更高效的 SNF 系统，在本研究中，我们应用具有可持续双原子催化作用的锰铁氧体纳米颗粒（MF-NPs）来产生活性氧（ROS），从而调节结瘤途径并增加大豆（Glycine max）的根瘤数量，最终增强共生固氮作用。MF-NPs 与大豆植物共生培养导致根瘤重量和数量分别增加了 50.85%和 61.4%，从而诱导固氮效率提高了 151.36%，最终尽管对单位氮酶活性没有实质性影响，但生物量积累增加了 25.70%。转录组测序分析表明，在晚期根瘤菌接种阶段（12 d），36 个差异表达基因（DEGs）中有 31 个与大豆结瘤相关的基因上调，表明根瘤数量的增加是由 MF-NPs 持续诱导结瘤相关基因（Nod-R）引起的。
我们的结果表明，通过延长结瘤期，可以有效地增加根瘤数量，而不会威胁植物的营养生长或触发结瘤的自动调节（AON）途径。本研究为超常规结瘤的诱导提供了一种有效的策略。
