Dong Qiqi, Su Huijie, Sun Yuexin, Zhao Yubiao, Zhou Dongying, Wang Xiaoguang, Jiang Chunji, Liu Xibo, Zhong Chao, Zhang He, Kang Shuli, Zhao Xinhua, Yu Haiqiu
Peanut Research Institute, College of Agronomy, Shenyang Agricultural University, Shenyang, Liaoning, China.
School of Agriculture and Horticulture, Liaoning Agricultural Vocational and Technical College, Yingkou, Liaoning, China.
Plant Cell Environ. 2024 Dec;47(12):4557-4571. doi: 10.1111/pce.15034. Epub 2024 Jul 19.
The fixation and transfer of biological nitrogen from peanuts to maize in maize-peanut intercropping systems play a pivotal role in maintaining the soil nutrient balance. However, the mechanisms through which root interactions regulate biological nitrogen fixation and transfer remain unclear. This study employed a N isotope labelling method to quantify nitrogen fixation and transfer from peanuts to maize, concurrently elucidating key microorganisms and genera in the nitrogen cycle through metagenomic sequencing. The results revealed that biological nitrogen fixation in peanut was 50 mg and transfer to maize was 230 mg when the roots interacted. Moreover, root interactions significantly increased nitrogen content and the activities of protease, dehydrogenase (DHO) and nitrate reductase in the rhizosphere soil. Metagenomic analyses and structural equation modelling indicated that nrfC and nirA genes played important roles in regulating nitrogen fixation and transfer. Bradyrhizobium was affected by soil nitrogen content and DHO, indirectly influencing the efficiency of nitrogen fixation and transfer. Overall, our study identified key bacterial genera and genes associated with nitrogen fixation and transfer, thus advancing our understanding of interspecific interactions and highlighting the pivotal role of soil microorganisms and functional genes in maintaining soil ecosystem stability from a molecular ecological perspective.
在玉米 - 花生间作系统中，生物固氮从花生向玉米的固定和转移在维持土壤养分平衡方面起着关键作用。然而，根系相互作用调节生物固氮和转移的机制仍不清楚。本研究采用氮同位素标记法量化从花生到玉米的固氮和转移，同时通过宏基因组测序阐明氮循环中的关键微生物和属。结果表明，当根系相互作用时，花生的生物固氮量为50毫克，向玉米的转移量为230毫克。此外，根系相互作用显著增加了根际土壤中的氮含量以及蛋白酶、脱氢酶（DHO）和硝酸还原酶的活性。宏基因组分析和结构方程模型表明，nrfC和nirA基因在调节固氮和转移中起重要作用。慢生根瘤菌受土壤氮含量和DHO的影响，间接影响固氮和转移效率。总体而言，我们的研究确定了与固氮和转移相关的关键细菌属和基因，从而增进了我们对种间相互作用的理解，并从分子生态学角度突出了土壤微生物和功能基因在维持土壤生态系统稳定性方面的关键作用。
