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.

We are looking for result-driven team player with creative ideas, excellent communication skills as well as good proficiency in English (both oral and written). This position requires an excellent English language proficiency (a mininum of CEFR C1 level). For more information about this proficiency level, please visit our special language page.

• You have a PhD in plant sciences and you have published some high-quality papers in peer-reviewed journals.
• You enjoy supervising BSc, MSc and PhD students and have excellent collaboration skills.
• You are capable to operate in an international and multi-disciplinary environment.
• You have proven a profound knowledge on plant physiological processes and how to create a mathematical description thereof.
• You can develop plant models using a popular programming langue such as: Java (XL), Javascript, Python, Matlab, R, or C++.
• Although the focus will be on fundamental experimental plant physiology, you should be well capable to translate and communicate your research findings with companies working in the vertical farming industry.

We are offering an exciting and challenging position for 3 years. A challenging position with, depending on your experience, a competitive salary from a minimum of €2.790,- to a maximum of €4.402,- for a full working week of 38 hours in accordance with the Collective Labor Agreement Wageningen University (scale 10). We offer you a temporary contract for 12 months which will be extended if you perform well.

In addition, we offer:

• 8% holiday allowance;
• an end-of-the-year bonus of 8.3% of your annual salary
• excellent training opportunities and secondary employment conditions;
• flexible working hours and holidays can possibly be determined in consultation so that an optimal balance between work and private life is possible;
• excellent pension plan through ABP;
• a choice model to put together part of your employment conditions yourself, such as a bicycle plan;
• a lively workplace where you can easily make contacts and where many activities take place on the Wageningen Campus. A place where education, research and business are represented;
• make use of the sports facilities on campus for a small fee.

Wageningen University & Research stimulates internal career opportunities and mobility with our internal recruitment policy. There are ample opportunities for personal initiative in a learning environment. With us you get a versatile job in an international environment with a pleasant and open working atmosphere, with students and staff from over 100 countries around the world.

You are going to work at the greenest and most innovative campus in Holland, and at a university that has been chosen as the "Best University" in the Netherlands for the 15th consecutive time.

Wageningen University & Research

The chair group Horticulture & Product Physiology
Together with a consortium of an inter-disciplinary team of researchers and companies, we are starting a large research programme of 17 PhDs/Postdocs entitled 'Sky High: Vertical farming, a revolution in plant production'.



The chair group Horticulture and Product Physiology conducts high impact research and educates students providing the scientific basis required to answer questions that are of utmost importance for sustainable crop production and product quality in horticulture.
The research focus is on how physiological processes in crops, plants and plant organs interact with the abiotic environment and how this affects crop production and product quality. Questions arising from horticultural practice are translated into fundamental research topics, aiming to explain mechanisms. The research and education contributes to sustainably feeding the World with healthy high-quality products.
The chair group is an international team consisting of 14 permanent staff members, about 25 PhD candidates and postdocs and a number of guest researchers. Each year about 40 MSc students conduct their thesis study (a 6-month research) at our group. We organize and participate in a variety of courses for BSc and MSc students to transfer knowledge on horticulture (pre- and post harvest), environmental physiology and product quality.
More info about the chair group can be found at www.hpp.wur.nl

The mission of our University is to explore the potential of nature to improve the quality of life. Within Wageningen University & Research, nine specialised research institutes from the Wageningen Research Foundation and Wageningen University have joined forces to help answer the most important questions in the domain of healthy food and living environment.
With approximately 30 locations, 6.500 employees, and 12.000 students, it is one of the leading organisations in its domain worldwide. An integrated approach to problems and the cooperation between various disciplines are at the heart of the unique approach of Wageningen. We have been named Best Employer in Education category 2019-2020.
Click here for more information about working at Wageningen University & Research. More information about Wageningen Campus you can find here.