Laboratory of Plant Ecology, Department of Applied Ecology and Environmental Biology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium.
Plant Sciences Unit, Institute of Agricultural, Fisheries and Food Research (ILVO), Melle, Belgium.
Ann Bot. 2018 Apr 18;121(5):849-861. doi: 10.1093/aob/mcx144.
In many scenarios the availability of assimilated carbon is not the constraining factor of plant growth. Rather, organ growth appears driven by sink activity in which water availability plays a determinant role. Current functional-structural plant models (FSPMs) mainly focus on plant-carbon relations and largely disregard the importance of plant water status in organogenesis. Consequently, incorporating a turgor-driven growth concept, coupling carbon and water dynamics in an FSPM, presents a significant improvement towards capturing plant development in a more mechanistic manner.
An existing process-based water flow and storage model served as a basis for implementing water control in FSPMs. Its concepts were adjusted to the scale of individual plant organs and interwoven with the basic principles of modelling carbon dynamics to allow evaluation of turgor pressure across the entire plant. This was then linked to plant organ growth by applying the principles of the widely used Lockhart equation.
This model successfully integrates a mechanistic understanding of plant water transport dynamics coupled with simple carbon dynamics within a dynamically developing plant architecture. It allows evaluation of turgor pressure on the scale of plant organs, resulting in clear diel and long-term patterns, directly linked to plant organ growth.
A conceptual sap flow and turgor-driven growth model was introduced for functional-structural plant modelling. It is applicable to any plant architecture and allows visual exploration of the diel patterns of organ water content and growth. Integrated in existing FSPMs, this new concept fosters an array of possibilities for FSPMs, as it presents a different formulation of growth in terms of local processes, influenced by local and external conditions.
在许多情况下，可同化碳的可用性并不是植物生长的限制因素。相反，器官生长似乎由汇活动驱动，而水分可用性在其中起着决定性作用。当前的功能结构植物模型（FSPMs）主要关注植物与碳的关系，在很大程度上忽略了植物水分状况在器官发生中的重要性。因此，将膨压驱动的生长概念纳入 FSPMs 中，将碳和水动力学耦合起来，是朝着以更机械的方式捕捉植物发育的方向迈出的重要一步。
现有的基于过程的水流和储存模型被用作在 FSPMs 中实施水分控制的基础。其概念被调整到单个植物器官的规模，并与建模碳动力学的基本原理交织在一起，以允许评估整个植物的膨压。然后，通过应用广泛使用的 Lockhart 方程的原理，将其与植物器官生长联系起来。
该模型成功地将植物水分运输动力学的机械理解与简单的碳动力学相结合，形成一个动态发展的植物结构。它允许在植物器官的规模上评估膨压，从而产生与植物器官生长直接相关的清晰的昼夜和长期模式。
引入了一个概念性的蒸腾流和膨压驱动的生长模型，用于功能结构植物建模。它适用于任何植物结构，并允许直观地探索器官水分含量和生长的昼夜模式。将这个新概念集成到现有的 FSPMs 中，可以为 FSPMs 带来一系列的可能性，因为它从局部过程的角度提出了一种不同的生长方式，这些过程受到局部和外部条件的影响。
