Are you that enthusiastic mathematical modeler that likes to address research question on plant physiology?
Vertical farming is a novel technology where plants are grown on many stacked layers with LED light. The ambition of the vertical farming industry is to warrant a secure and sustainable vegetable supply: no pesticides, no nutrient emission, only 2-4 litres water per kg produce, at least twentyfold less land use, lower food mileage, less waste and lower energy use per kg produce compared to greenhouses. Within the vertical farming research teams of HPP, this particular post-doc project will use a Functional-Structural Plant (FSP) modelling approach to gain fundamental understanding of two plant physiological phenomena relevant in the context of vertical farming: (i) root-shoot signaling and (ii) tip-burn. (i) In horticulture little attention has been paid to rooting media properties like root penetration resistance, which can directly affect plant morphology. That is, plants respond to perceived mechanical perturbations by modifying their morphology, a process called thigmomorphogenesis. Thigmomorphogenesis can occur on the location of perturbation, but within minutes a sudden drop in elongation growth can also be observed far away from the perturbed area. There are different hypotheses for the mechanisms behind this "long-distance signalling". Next to hormonal and electrical mechanisms, a popular hypothesis revolves around hydraulic pulses. To address this hypothesis, we will assess the dose response relation between root penetration resistance and leaf elongation rates. A dose and duration dependent relationship between the intensity of compressive force and thigmomorphogenetic response has already been established for shoots, but is lacking for roots. You will develop a functional structural plant (FSP) model, using newly developed and existing modelling concepts, to narrow down candidate mechanisms for root-borne long-distance signalling, i.e. hormonal, electrical or hydraulic. This work will be done in close collaboration with another
post-doc who addresses the issue experimentally, which will provide you with targeted high quality data for FSP model development on root-shoot signaling. (ii) Tipburn, brown necrotic edges of the leaves, is a widespread problem in the production of leafy vegetables. Vertical farming opens up possibilities to grow leafy vegetables without tipburn, however this potential is not yet realized. Tipburn is generally considered as a consequence of local calcium (Ca) deficiency resulting in faster cell wall degradation, loss of membrane integrity and premature senescence. Understanding tipburn requires understanding of calcium distribution which is directly related to transpiration distribution in the plant. Functional-Structural Plant (FSP) modelling will be employed combining the representation of three-dimensional (3D) plant structure with spatially resolved photosynthesis, transpiration and Ca distribution. There is already a vast amount of data available on tip burn. However, the other
post-doc will conduct experiments to do targeted data collection that will support the development of this FSP model for lettuce. In the end the FSP model should allow for localised simulation of carbon, water and Ca flow which is a unique scientific challenge. Both Functional-Structural Plant (FSP) modelling project, i.e. conceptualizing root-shoot signaling and tip-burn in lettuce, will share many concepts and are therefore combined into one post-doc focused on mathematical modelling. Your work will be strongly linked to the associated post-doc who focuses on experimental approaches addressing the same questions.