Minchin P E H, Lacointe A
ICG-III Phytosphaere, Forschungszentrum Juelich, D 52425 Juelich, Germany.
New Phytol. 2005 Jun;166(3):771-9. doi: 10.1111/j.1469-8137.2005.01323.x.
Most current models of assimilate carbohydrate partitioning are based on growth patterns observed under a range of experimental conditions, from which a set of empirical rules are derived to simulate partitioning. As a result, they are not good at extrapolating to other conditions; this requires a mechanistic approach, which only transport-resistance (TR) models currently provide. We examine an approach to incorporating recent progress in phloem physiology into the TR approach, which leads to a 'minimalist' Munch model of a branched system with competing sinks. In vivo whole-plant measurements have demonstrated that C-flow rates are dependent not only on the properties of the sink, but also on the properties of the whole transport system, and the detailed dynamics of this behaviour is mimicked by the proposed model. This model provides a sound theoretical framework for an unambiguous definition of sink and source strengths, with sink priority being an emergent property of the model. Further developments are proposed, some of which have already had limited application, to cope with the complexity of plants; the emphasis is on a modular approach, together with the importance of choosing the appropriate scale level for both structure and function. Whole-plant experiments with in vivo measurement of the phloem dynamics will be needed to help with this choice.
目前大多数同化物碳水化合物分配模型是基于在一系列实验条件下观察到的生长模式，从中推导出一组经验规则来模拟分配过程。因此，它们不擅长外推到其他条件；这需要一种机械方法，而目前只有运输阻力（TR）模型能提供这种方法。我们研究了一种将韧皮部生理学的最新进展纳入TR方法的途径，这导致了一个具有竞争库的分支系统的“极简主义”明希模型。体内全株测量表明，碳流速率不仅取决于库的特性，还取决于整个运输系统的特性，并且该行为的详细动态由所提出的模型模拟。该模型为明确界定库和源强度提供了一个合理的理论框架，库优先级是该模型的一个涌现特性。为了应对植物的复杂性，我们提出了进一步的发展方向，其中一些已经有了有限的应用，重点是模块化方法，以及为结构和功能选择合适尺度水平的重要性。需要进行体内测量韧皮部动态的全株实验来辅助做出这种选择。
