Data_Stress-mediated variation in growth and adaptive ploidy plasticity in an invasive grass

Localized increase in cellular ploidy—endopolyploidy— is a common phenomenon during development and is also a primary response to stressful environments for many plant and animal species. Yet the evolvability of endopolyploidy as a plant stress response and its ecological consequences remain important open questions. Here we use 23 populations of a globally invasive grass collected from agricultural and non-agricultural habitat types to test for intraspecific variation in endopolyploidy levels, and how it corresponds with plant performance in response to three major stresses (herbicide exposure, simulated herbivory/mowing, and competition). Overall, plants significantly increased cell ploidy in response to herbicides and simulated herbivory/mowing, but not to competition. We found distinct phenotypic and endopolyploidy responses between plants from agricultural and non-agricultural habitats following herbicide application—suggesting that genotypic variation in ploidy plasticity may be adaptive, involved in compensatory growth responses, and influence plant-plant interactions. Populations with lower levels of endopolyploidy performed better in the field under intense competition with weeds, whereas populations with more endopolyploidy performed better under competition with corn. Together, our results shed light on an understudied adaptive response which plays an important role in how plants interact with each other, mitigate stress, and adapt to different environments.

细胞倍性的地域性增加——内多倍性——在生物发育过程中是一种普遍现象，同时也是许多植物和动物物种对压力环境的主要响应机制。然而，内多倍性作为植物对压力环境的适应性进化及其生态后果，仍是一个重要的未解之谜。在本研究中，我们利用从全球入侵性草地农业和非农业生境类型中收集的23个种群，测试了内多倍性水平的种内变异，及其与植物对三种主要压力（除草剂暴露、模拟食草/修剪和竞争）的响应之间的关系。总体而言，植物对除草剂和模拟食草/修剪的响应表现为显著增加细胞倍性，而对竞争的响应则没有变化。我们发现，在除草剂处理后，农业和非农业生境的植物在表型和内多倍性响应上存在显著差异——这表明倍性可塑性的基因型变异可能具有适应性，参与补偿性生长反应，并影响植物间的相互作用。在杂草激烈竞争的田间环境中，具有较低内多倍性水平的种群表现更佳，而在与玉米的竞争中，具有较高内多倍性的种群表现更佳。综上所述，我们的研究结果揭示了植物相互作用的适应性响应机制，这一机制在植物如何相互影响、缓解压力和适应不同环境方面发挥着重要作用。