Flathead Lake Biological Station, University of Montana, Polson, Montana, USA.
Department of Biology, Lund University, Lund, Sweden.
Ecol Lett. 2022 Oct;25(10):2324-2339. doi: 10.1111/ele.14096. Epub 2022 Sep 11.
The growth rate hypothesis (GRH) posits that variation in organismal stoichiometry (C:P and N:P ratios) is driven by growth-dependent allocation of P to ribosomal RNA. The GRH has found broad but not uniform support in studies across diverse biota and habitats. We synthesise information on how and why the tripartite growth-RNA-P relationship predicted by the GRH may be uncoupled and outline paths for both theoretical and empirical work needed to broaden the working domain of the GRH. We found strong support for growth to RNA (r = 0.59) and RNA-P to P (r = 0.63) relationships across taxa, but growth to P relationships were relatively weaker (r = 0.09). Together, the GRH was supported in ~50% of studies. Mechanisms behind GRH uncoupling were diverse but could generally be attributed to physiological (P accumulation in non-RNA pools, inactive ribosomes, translation elongation rates and protein turnover rates), ecological (limitation by resources other than P), and evolutionary (adaptation to different nutrient supply regimes) causes. These factors should be accounted for in empirical tests of the GRH and formalised mathematically to facilitate a predictive understanding of growth.
生长率假说（GRH）认为，生物体化学计量学（C:P 和 N:P 比值）的变化是由生长过程中磷向核糖体 RNA 的分配所驱动的。GRH 在跨多种生物群和生境的研究中得到了广泛但并非一致的支持。我们综合了有关 GRH 所预测的三部分生长-RNA-磷关系如何以及为何可能解耦的信息，并概述了拓宽 GRH 工作范围所需的理论和实证工作的途径。我们发现，跨分类群存在强烈的生长到 RNA（r=0.59）和 RNA 到 P（r=0.63）关系的支持，但生长到 P 的关系相对较弱（r=0.09）。总的来说，GRH 在大约 50%的研究中得到了支持。GRH 解耦的背后机制多种多样，但通常可以归因于生理（非 RNA 池中的磷积累、无活性核糖体、翻译延伸率和蛋白质周转率）、生态（除磷以外的资源限制）和进化（适应不同的养分供应制度）原因。在 GRH 的实证检验中应考虑这些因素，并进行数学形式化，以促进对生长的预测性理解。
