John Innes Centre, Norwich, NR4 7UH, UK.
Stanford University, Palo Alto, CA, 94305, USA.
New Phytol. 2024 Jan;241(2):937-949. doi: 10.1111/nph.19228. Epub 2023 Aug 29.
The first land ecosystems were composed of organisms considered simple in nature, yet the morphological diversity of their flora was extraordinary. The biological significance of this diversity remains a mystery largely due to the absence of feasible study approaches. To study the functional biology of Early Devonian flora, we have reconstructed extinct plants from fossilised remains in silico. We explored the morphological diversity of sporangia in relation to their mechanical properties using finite element method. Our approach highlights the impact of sporangia morphology on spore dispersal and adaptation. We discovered previously unidentified innovations among early land plants, discussing how different species might have opted for different spore dispersal strategies. We present examples of convergent evolution for turgor pressure resistance, achieved by homogenisation of stress in spherical sporangia and by torquing force in Tortilicaulis-like specimens. In addition, we show a potential mechanism for stress-assisted sporangium rupture. Our study reveals the deceptive complexity of this seemingly simple group of organisms. We leveraged the quantitative nature of our approach and constructed a fitness landscape to understand the different ecological niches present in the Early Devonian Welsh Borderland flora. By connecting morphology to functional biology, these findings facilitate a deeper understanding of the diversity of early land plants and their place within their ecosystem.
最早的陆地生态系统由被认为性质简单的生物组成，但它们的植物形态多样性却非常惊人。由于缺乏可行的研究方法，这种多样性的生物学意义仍然是一个谜。为了研究早泥盆世植物群的功能生物学，我们已经从化石中重建了灭绝植物的计算机模型。我们使用有限元法研究了孢子囊的形态多样性与其力学特性之间的关系。我们的方法强调了孢子囊形态对孢子传播和适应的影响。我们发现了早期陆地植物中以前未被识别的创新，讨论了不同物种可能如何选择不同的孢子传播策略。我们展示了耐压性趋同进化的例子，球形孢子囊通过均匀化压力以及类似 Tortilicaulis 的标本的扭转力来实现，此外，我们还展示了一种用于辅助孢子囊破裂的潜在机制。我们的研究揭示了这个看似简单的生物群体的欺骗性复杂性。我们利用了我们方法的定量性质，并构建了一个适应度景观，以了解早泥盆世威尔士边界植物群中存在的不同生态位。通过将形态与功能生物学联系起来，这些发现有助于更深入地了解早期陆地植物的多样性及其在生态系统中的地位。
