A general model for seed and seedling respiratory metabolism

The ontogeny of seed plants usually involves a dormant dehydrated state and the breaking of dormancy and germination, which distinguishes it from that of most organisms. Seed germination and seedling establishment are critical ontogenetic stages in the plant life cycle and both are fueled by respiratory metabolism. However, the scaling of metabolic rate with respect to individual traits remains poorly understood. Here, we tested metabolic scaling theory during seed germination and early establishment growth using a recently developed model and empirical data collected from 41 species. The results show that (i) the mass-specific respiration rate (Rm) is weakly correlated with body mass, mass-specific N, and C content, (ii) Rm conformed to a single Michaelis-Menten curve as a function of tissue water content, and (iii) the central parameters in the model were highly correlated with DNA content and critical enzyme activities. The model offers new insights and a more integrative scaling the...

种子植物的个体发育（ontogeny）通常包含休眠脱水状态、休眠打破与萌发过程，这一特征使其区别于绝大多数其他生物。种子萌发与幼苗建成是植物生命周期中至关重要的个体发育阶段，二者均依赖呼吸代谢供能。然而，代谢速率与个体性状间的缩放关系仍未得到充分阐释。本研究借助新近开发的模型与采集自41个物种的实验数据，对种子萌发及早期建成生长阶段的代谢缩放理论（metabolic scaling theory）展开了检验。研究结果显示：（i）单位质量呼吸速率（mass-specific respiration rate，记作Rm）与个体质量、单位质量氮、碳含量仅存在弱相关关系；（ii）单位质量呼吸速率随组织含水量变化的拟合曲线符合单一米氏曲线（Michaelis-Menten curve）；（iii）模型核心参数与DNA含量及关键酶活性存在显著相关关系。该模型为代谢缩放相关研究提供了全新视角与更具整合性的缩放……