Escola Superior de Biotecnologia, Catholic University of Portugal, Rua Diogo Botelho, 1327, Porto, 4169-005, Portugal.
Precision Agriculture Lab, School of Life Sciences, Technical University of Munich, Dürnast 9, 85354, Freising, Germany.
BMC Plant Biol. 2024 Oct 25;24(1):1001. doi: 10.1186/s12870-024-05614-3.
Colonization by Ectomycorrhizal (EcM) fungi is key for the health and performance of plants under different stress scenarios, such as those faced by trees in urban environments. Because urban environments can be lacking EcM fungi, we here assessed the benefits of inoculating Tilia tomentosa seedlings in a pre-transplantation nursery context with the EcM fungi Lactarius deliciosus and Paxillus involutus, using substrates of different pH and facing water-stress. P. involutus had a more evident positive effect in T. tomentosa seedlings and had a good performance in both acidic and alkaline substrate. In acidic substrate the fungus increased the plant height by 0.91-fold, increased the mycorrhization rate by 3.23-fold, expansion rate by 5.03-fold and formation of secondary roots by 0.46-fold, compared to the non-inoculated control. This species also improved the phosphorus content of leaves, which revealed a promotion of nutrient uptake. In alkaline substrate P. involutus increased root dry weight by 3.92-fold and the mycorrhization parameters. In contrast, L. deliciosus only had a positive effect in the improvement of mycorrhization and expansion rates and phosphorus content in the root, effects visible only in alkaline substrate. When exposed to water-stress the increase of proline content was visible in acidic substrate for both fungi, L. deliciosus and P. involutus, and in alkaline substrate for the fungus P. involutus, a response indicative of the enhancement of defenses in stressing scenarios such as water scarcity. We conclude that fungal inoculation improves the vigour and resilience of Tilia seedlings and that it is of utmost importance to select a suitable EcM fungus and to consider the soil pH of the transplanting site. The inoculation approach can be a valuable tool to produce robust seedlings which may have a better performance when transplanted to the challenging urban environment.
外生菌根（EcM）真菌的定殖是植物在不同胁迫环境下（如城市环境中树木所面临的情况）健康和性能的关键。由于城市环境中可能缺乏 EcM 真菌，我们在这里评估了在移植前苗圃环境中用 EcM 真菌乳菇（Lactarius deliciosus）和离褶伞（Paxillus involutus）对绒毛梣（Tilia tomentosa）幼苗进行接种的益处，使用了不同 pH 值的基质并面临水分胁迫。在酸性基质中，P. involutus 对绒毛梣幼苗的影响更为明显，在酸性和碱性基质中都有较好的表现。与未接种对照相比，该真菌使植株高度增加了 0.91 倍，使菌根侵染率增加了 3.23 倍，根扩展率增加了 5.03 倍，次生根形成率增加了 0.46 倍。该物种还提高了叶片的磷含量，表明促进了养分吸收。在碱性基质中，P. involutus 使根干重增加了 3.92 倍，还增加了菌根参数。相比之下，L. deliciosus 仅在碱性基质中对菌根侵染率、根扩展率和根磷含量的提高有积极影响。当暴露在水分胁迫下时，两种真菌（L. deliciosus 和 P. involutus）在酸性基质中以及真菌 P. involutus 在碱性基质中都可见脯氨酸含量增加，这表明在缺水等胁迫情况下增强了防御能力。我们得出结论，真菌接种可提高绒毛梣幼苗的活力和抗逆性，选择合适的 EcM 真菌并考虑移植地点的土壤 pH 值至关重要。接种方法可以是一种有价值的工具，可以生产出健壮的幼苗，这些幼苗在移植到具有挑战性的城市环境中时可能会有更好的表现。
