Sun Shan, Li Mengsha, Tao Luchen, Liu Xiran, Ouyang Lei, Li Gen, Hu Feng, Li Huixin
The Sanya Institute of Nanjing Agricultural University, Nanjing Agricultural University, Sanya 572025, China.
Soil Ecology Laboratory, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 211800, China.
Microorganisms. 2025 Aug 21;13(8):1951. doi: 10.3390/microorganisms13081951.
, a free-living nematode model, secretes neuropeptides, but the ecological roles of its peptide exudates in regulating rhizosphere microbial activity remain largely unexplored. We identified six short peptides (P1, P9, P19, P20, P25, and P26) from exudates that significantly enhanced indole-3-acetic acid (IAA) production by the plant growth-promoting bacterium ZZ21. These peptides were heat-labile and proteinase K-sensitive but unaffected by DNase I or RNase A, confirming their proteinaceous (peptide) nature rather than nucleic acid origin. The retention of bioactivity in n-butanol extracts further supported their hydrophilic, peptide-like properties. LC-MS/MS identified 30 linear peptides, including the six bioactive ones, which exhibited distinct dose-dependent effects, suggesting diverse regulatory mechanisms. Despite their relatively low abundance, these peptides strongly promoted IAA production in the bacterial culture system across multiple concentrations. These findings reveal an unrecognized mechanism whereby free-living nematodes regulate rhizobacterial metabolism via secreted peptides, offering new insights into nematode-mediated chemical signaling. Therefore, this study advances understanding of plant-microbe-nematode interactions and highlights strategies for manipulating rhizosphere microbiota in sustainable agriculture.
作为一种自由生活的线虫模型，会分泌神经肽，但其肽类分泌物在调节根际微生物活性方面的生态作用仍 largely unexplored（大部分未被探索）。我们从分泌物中鉴定出六种短肽（P1、P9、P19、P20、P25和P26），这些短肽显著增强了植物促生细菌ZZ21的吲哚 - 3 - 乙酸（IAA）产量。这些肽对热不稳定且对蛋白酶K敏感，但不受DNase I或RNase A影响，证实了它们的蛋白质（肽）性质而非核酸来源。正丁醇提取物中生物活性的保留进一步支持了它们的亲水性、肽样性质。LC - MS/MS鉴定出30种线性肽，包括六种生物活性肽，它们表现出不同的剂量依赖性效应，表明存在多种调节机制。尽管它们的丰度相对较低，但这些肽在多个浓度下都强烈促进了细菌培养系统中IAA的产生。这些发现揭示了一种未被认识的机制，即自由生活的线虫通过分泌肽来调节根际细菌的代谢，为线虫介导的化学信号传导提供了新的见解。因此，本研究推进了对植物 - 微生物 - 线虫相互作用的理解，并突出了在可持续农业中操纵根际微生物群的策略。
