Aarhus University Seal / Aarhus Universitets segl

Nikolaj Bjerring Jensen


Nikolaj Bjerring Jensen


PhD project: Stomatal regulation and development in a climate change perspective

University: Aarhus University
Department: Department of Food Science
Supervisor: Carl-Otto Ottosen, Professor with Special Responsibilities
Co-supervisor: Rong Zhou, Assistant Professor
Project term: 01.06.19 – 31.05.22
Master’s degree: MSc in Molecular Nutrition and Food Technology, Aarhus University




The global community is facing increasing challenges in food supply due to climate change and increasing population. One of the consequences of global climate change is more extreme weather conditions, and the frequency of periods of extreme heat and drought is expected to increase, making these abiotic stress factors one of the top threads against crop performance and yield in future’s agriculture. The individual effects of heat or drought on plant physiology has been studied in great detail. However, a growing body of recent research has demonstrated that combination of abiotic stress factors cause unique effects that are not explained by the sum of the effects of the individual stress factors applied. The relatively new research field of combined stress is therefore important for describing the physiological mechanisms for adaption to multi-stressed environments. This new knowledge is important for avoiding possible pitfalls when transferring new developments or genetics from controlled lab conditions to multi-stressed field conditions in food production.

One of the key aspects of plant physiology where heat and drought cause conflicting effects is in stomatal regulation. Stomata are small pores on the leaf surface, that can open and close is order to regulate the transpiration of water from the leaf and the uptake of CO2 from the air. During drought plants will close stomata in order to conserve water, while they will open them during heat stress to allow for evaporative cooling. So faced with the combination of heat and drought stress, stomatas encounters one of the central dilemmas in the adaption strategy for the plant: whether to close and conserve water, or open to allow for cooling.




My project aims to describe the interactions of heat and drought at elevated levels of CO2 in the regulation and development of stomata, with a focus on the mechanistic roles of the phytohormones ABA and melatonin.  




Different genotypes of tomato with differing tolerance towards heat and drought will be cultivated in different combinations of heat, drought, elevated CO2 and application of the phytohormone melatonin to study the responses in stomatal behavior and the effects in plant stress levels. The regulation of stomata will be assessed by physiological measurements and by LC-MS profiling of ABA, while the development of stomata will be studied through transcriptional analysis. The stress levels of the plants will be studied by chlorophyll fluorescence and by analysis of metaboilites and enzymes related to oxidative damage.




Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun

Vis alle (7) »

ID: 96841844