Despite the crucial role of microbial communities in agroecosystem functioning, a clear picture of how nitrogen shapes rhizosphere microbial complexity and community structure across diverse maize lines remains elusive. To address this gap, we conducted 16S amplicon sequencing of the rhizosphere microbial communities across a diverse range of maize inbred lines (305 genotypes) and their F1 hybrids (196 genotypes) cultivated in both low-nitrogen (unfertilized) and high-nitrogen (fertilized) soils. Our findings reveal that N fertilizer treatment had contrasting effects on the rhizosphere microbial communities of inbreds and hybrids. N fertilization increased alpha diversity but decreased the abundance of Pseudomonas taxa in inbred lines, while the opposite was true for hybrids. The proportion of variance determined by plant host factors was also better explained under low-N, demonstrating that N fertilization reduced the influence of the host over the rhizosphere microbial community. Microbial networks revealed significant differences in the number of nodes and clustering coefficients between the rhizosphere microbial communities of inbred and hybrid maize, with these differences being further differentiated by changes in nitrogen levels. Overall, our study reveals the interplay among rhizosphere microbiomes, abiotic stress induced by low soil nitrogen, and plant host factors facilitating the identification of stable microbial communities in response to environmental stress. These findings contribute to the potential engineering of resilient microbial consortia highlighting the importance of the influence of plant genotype and the environment on the rhizosphere microbiome.

尽管微生物群落在农业生态系统功能中发挥着至关重要的作用，但氮如何影响不同玉米品系根际微生物复杂性和群落结构的清晰图景仍然难以捉摸。为了解决这一差距，我们对在低氮（未受精）和高氮（受精）条件下栽培的各种玉米自交系（305 个基因型）及其 F1 杂种（196 个基因型）的根际微生物群落进行了 16S 扩增子测序。 ）土壤。我们的研究结果表明，氮肥处理对自交系和杂交系的根际微生物群落具有截然不同的影响。施氮肥增加了自交系中的α多样性，但降低了假单胞菌类群的丰度，而对于杂种来说则相反。在低氮条件下，由植物寄主因素决定的方差比例也得到了更好的解释，表明施氮肥降低了寄主对根际微生物群落的影响。微生物网络揭示了自交系和杂交玉米根际微生物群落之间节点数量和聚类系数的显着差异，这些差异通过氮水平的变化进一步区分。总体而言，我们的研究揭示了根际微生物组、低土壤氮引起的非生物胁迫以及植物宿主因素之间的相互作用，有助于识别稳定的微生物群落以应对环境胁迫。这些发现有助于弹性微生物群落的潜在工程，强调植物基因型和环境对根际微生物组影响的重要性。