Naturalis Biodiversity Center in Leiden is the Dutch national research institute for biodiversity and systematics. With our collection of 42 million specimens, one of the world’s largest natural history collections, and our state-of-the-art research facilities we offer the (inter)national research infrastructure for species, identification and monitoring (for example in the ARISE and DiSSCo projects). We closely collaborate with many Dutch universities, research institutes, industry, and government. We host over 120 researchers including 14 academia embedded professors and 40 PhD students. We present the history of our planet, and the diversity of life on Earth, through permanent and temporary museum exhibitions, educational programmes, and online presence, with more than 400,000 visitors per year. All in all, a unique combination of science and culture in the Netherlands and elsewhere in the world!


Lignin is a plant biopolymer that is highly concentrated in so-called lignified cell walls. Although lignified cell walls can be found in all kinds of vegetative and reproductive plant organs, cell wall lignification is pronounced within the wood tissue, which is developed by a lateral meristem that is responsible for most of the lateral stem and root growth in woody species. In flowering plants, hundreds of non-woody (herbaceous) lineages independently gave rise to new woody species, suggesting that: i) woodiness provides a fitness advantage in (seasonally) dry environments, and ii) only few genetic key regulatory changes are required for the transition from herb to shrub. Interestingly, lignin production in herbaceous stems can also be enhanced in response to drought stress. As such, increased lignin deposition in plant cell walls as well as increased wood formation in stems and roots have been suggested by a range of pilot studies as a key strategy for drought resilience during plant evolution. 

The selected PhD candidate will perform detailed anatomical observations and monitor the drought response (e.g., stomatal conductance, water potential, P50) in stems, roots and leaves in three plant lineages comprising accessions with contrasting levels of lignification and/or woodiness: Arabidopsis, tomato and cabbage. The PhD candidate will collaborate with five other PhD candidates, embedded in a novel multidisciplinary consortium uniquely bridging expertise in plant anatomy, evolution, development, physiology, genetics, molecular biology and lignin chemistry. Two of them will work close by at the university of Leiden (IBL: Institute of Biology Leiden) on gene regulation of wood development or cell lignification in stems under long evolutionary time scales as well as in response to short-term drought. Three other PhD candidates will focus on disentangling the woodiness phenotype from the late flowering phenotype (Wageningen University & Research), analyzing lignin chemical structure and the cell wall structure of lignified tissue in relation to drought tolerance (Wageningen University & Research), and assessing utilization of stems as biobased material in left‐over plant parts (University of Groningen). 

This vacancy only applies to the PhD position at Naturalis, with Dr. Lens as daily supervisor. The project fits within the work of Dr. Lens who explores structure-function relationships in a number of woody and herbaceous lineages. One aspect of his work investigates whether drought has driven the development of woodiness during evolutionary history (for more information: . The PhD student will be housed at Naturalis (Leiden, The Netherlands) where the facilities for anatomical observations and embolism resistance measurements (optical technique) are present. Plants will be grown in the growth chambers at IBL. Regular short-term meetings/visits to the labs of the other five PIs in- or outside Leiden are required to facilitate communication within the consortium. At Naturalis, the research department is organized in eight research groups comprising researchers and their postdocs and PhD-students. Dr. Frederic Lens is group leader of one of these research groups called ‘Functional Traits’. Find out more about Naturalis’ research, labs and collection. The PhD candidate will graduate at Leiden University.

General requirementsand skills

Preferably the candidate has the following skill set:

  • background in plant hydraulics;
  • experience with plant anatomy;
  • experience with growing plants;
  • genuine interest to know how plants cope with drought;
  • excellent knowledge of the English language (written and verbal);
  • scientific and critical attitude, excellent time management and organizational skills;
  • ability to work independently as well as collaboratively within the consortium;
  • good communication skills;
  • willingness to supervise MSc students and assist in practical courses on plant anatomy. 

It is expected that the successful candidate will spend time during several short research visits to Wageningen and Groningen (The Netherlands), and part of the work (plant growing) will be done at the nearby facilities of Leiden University (IBL). A close collaboration with the other PhD candidates is mandatory, although the Naturalis PhD project stands on its own.


A contract (36 hours per week) for a period of one year, to be extended with three more years after a successful first year evaluation (4y in total), and a monthly starting salary of € 2.940,-. You also get an allowance for travel expenses, holiday allowance (8%) and year-end bonus (3.4%). The successful candidate will be employed by Naturalis in Leiden. Naturalis Biodiversity Center offers an inspiring working atmosphere with effective and efficient supervision of our PhD candidates. Our Research Coordination Office also provides ample support to our scientific staff. Our institute promotes gender equality and wants to enhance the diversity of staff members.


Applicants are invited to submit their application in one pdf, including a cover/motivation letter and CV. In this motivation letter, contact information about two referees who have had close academic contact with the applicant should be included. Please use this form for your application before November 15th CET. Interviews are foreseen to take place in December 2022. The PhD position is expected to start February-April 2023. Feel free to contact Dr. Frederic Lens ( with questions about the position or HR ( with questions about the procedure.

Naturalis endorses the Cultural Diversity Code. In the case of equal suitability, preference is given to the candidate who reinforces diversity within the team.

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