Xie Jiyu, Sun Xinli, Xia Yanwei, Tao Lili, Tan Taimeng, Zhang Nan, Xun Weibing, Zhang Ruifu, Kovács Ákos T, Xu Zhihui, Shen Qirong
Jiangsu Provincial Key Lab for Solid Organic Waste Utilization, Key Lab of Organic-based Fertilizers of China, Jiangsu Collaborative Innovation Center for Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving Fertilizers, Nanjing Agricultural University, Nanjing, 210095, China.
Institute of Biology Leiden, Leiden University, 2333 BE, Leiden, the Netherlands.
Biofilm. 2024 Nov 16;8:100239. doi: 10.1016/j.bioflm.2024.100239. eCollection 2024 Dec.
Bacterial-fungal interactions (BFIs) are important in ecosystem dynamics, especially within the soil rhizosphere. The bacterium SQR9 and the fungus NJAU 4742 have gathered considerable attention due to their roles in promoting plant growth and protecting their host against pathogens. In this study, we utilized these two model microorganisms to investigate BFIs. We firstly demonstrate that while co-inoculation of and could promote tomato growth, these two microorganisms display mutual antagonism on agar solidified medium. To resolve this contradiction, we developed an inoculation method, that allows colonization of . hyphae and performed a transcriptome analysis. During colonization of the fungal hyphae, SQR9 upregulates expression of biofilm related genes (e.g. , and that is distinct from free-living cells. This result suggested an intricate association between extracellular matrix expression and hyphae colonization. In accordance, deletion , both and genes of diminished colonization of the . hyphae. The insights from our study demonstrate that soil BFIs are more complex than we understood, potentially involving both competition and cooperation. These intricate biofilm-mediated BFI dynamics might contribute to the remarkable diversity observed within soil microbiota, providing a fresh perspective for further exploration of BFIs in the plant rhizosphere.
细菌 - 真菌相互作用（BFIs）在生态系统动态中很重要，尤其是在土壤根际环境中。细菌SQR9和真菌NJAU 4742因其在促进植物生长和保护宿主免受病原体侵害方面的作用而备受关注。在本研究中，我们利用这两种模式微生物来研究细菌 - 真菌相互作用。我们首先证明，虽然共同接种SQR9和NJAU 4742可以促进番茄生长，但这两种微生物在琼脂固化培养基上表现出相互拮抗作用。为了解决这一矛盾，我们开发了一种接种方法，使SQR9能够在NJAU 4742的菌丝上定殖，并进行了转录组分析。在真菌菌丝定殖过程中，SQR9上调了与生物膜相关基因（如epsA、epsB和tapA）的表达，这与自由生活细胞不同。这一结果表明细胞外基质表达与菌丝定殖之间存在复杂的关联。相应地，缺失SQR9的epsA、epsB和tapA基因会减少其在NJAU 4742菌丝上的定殖。我们研究的见解表明，土壤中的细菌 - 真菌相互作用比我们所理解的更为复杂，可能涉及竞争与合作。这些复杂的生物膜介导的细菌 - 真菌相互作用动态可能有助于解释土壤微生物群中观察到的显著多样性，为进一步探索植物根际的细菌 - 真菌相互作用提供了新的视角。
