Emelianova Katie, Hawranek Anna-Sophie, Eriksson Mimmi C, Wolfe Thomas M, Paun Ovidiu
Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, Vienna, A-1030, Austria.
Vienna Graduate School of Population Genetics, Vienna, Austria.
Plant J. 2025 Feb;121(4):e70001. doi: 10.1111/tpj.70001.
Phenotypic plasticity, the dynamic adjustment of traits to environmental variations, is crucial for enabling species to exploit broader niches and withstand suboptimal conditions. This adaptability is particularly relevant for newly formed allopolyploids, which possess redundant gene copies and must become established in diverse environments distinct from their parents and other relatives. By evaluating gene expression and root mycobiome among two ecologically divergent sibling allopolyploid marsh orchids (Dactylorhiza majalis and D. traunsteineri) in reciprocal transplants at localities where both species are native, we aimed to understand the drivers of species persistence in the face of interspecific gene flow. Despite consistent abiotic differences characterising the alternative environments at each locality, the majority of gene expression differences between the allopolyploids appears to be plastic. Ecologically relevant processes, such as photosynthesis and transmembrane transport, include some genes that are differentially expressed between the two orchids regardless of the environment, while others change their activity plastically in one species or the other. This suggests that although plasticity helps define the specific ecological range of each sibling allopolyploid, it also mediates gene flow between them, thereby preventing differentiation. Extending our investigations to the root mycobiome, we uncover more diverse fungal communities for either species when grown in the environment with nutrient-poor soils, indicating that both abiotic and biotic factors drive the distribution of sibling marsh orchids. Altogether, our results indicate that plasticity can simultaneously promote diversification and homogenisation of lineages, influencing the establishment and persistence of recurrently formed allopolyploid species.
表型可塑性，即性状对环境变化的动态调整，对于物种开拓更广泛的生态位和抵御次优条件至关重要。这种适应性对于新形成的异源多倍体尤为重要，它们拥有冗余的基因拷贝，必须在与其亲本和其他亲属不同的多样化环境中立足。通过在两个物种均为原生的地点进行相互移植，评估两种生态差异较大的同属异源多倍体沼泽兰花（大花杓兰和特劳恩施泰纳杓兰）之间的基因表达和根真菌群落，我们旨在了解面对种间基因流时物种持续存在的驱动因素。尽管每个地点的替代环境存在一致的非生物差异，但异源多倍体之间的大多数基因表达差异似乎是可塑性的。与生态相关的过程，如光合作用和跨膜运输，包括一些在两种兰花之间无论环境如何都有差异表达的基因，而其他基因则在其中一个物种或另一个物种中发生可塑性活性变化。这表明，虽然可塑性有助于界定每个同属异源多倍体的特定生态范围，但它也介导了它们之间的基因流，从而防止分化。将我们的研究扩展到根真菌群落，我们发现当在土壤贫瘠的环境中生长时，两种兰花的真菌群落更加多样化，这表明非生物和生物因素都驱动着同属沼泽兰花的分布。总之，我们的结果表明，可塑性可以同时促进谱系的多样化和同质化，影响反复形成的异源多倍体物种的建立和持续存在。
