Plant Ecophysiology

The research group
The Plant Ecophysiology group at Utrecht University studies the complex interactions between plants and their environment. We focus on physiological and molecular mechanisms that enable plants to cope with flooded conditions and/or dense, competitive environments. These stress conditions induce changes in plant growth, helping plants to either overgrow high water levels or to outcompete neighbours in dense vegetations.  We combine experimental approaches from a variety of disciplines, and these include hormone physiology, transcriptomics (RNA-seq, microarrays, qPCR), growth analyses, protein abundance and activity, functional genomics and functional ecology.

 find us on Facebook




1. Flooding tolerance
The group has a strong history in studying flooding tolerance in wild plants, with emphasis on the wetland plant Rumex palustris. When submerged, terrestrial plants suffer from a shortage of CO2 diffusion into the plants which limits photosynthesis, and from oxygen shortages particularly in the roots. Studies to unravel how plants can escape from flooded conditions through shoot elongation growth has provided the following current understanding: Ethylene is the prime detection signal for submergence, and leads to down regulation of endogenous ABA. As a result GA levels go up which stimulates growth. In addition, expansin genes are induced to allow cell wall loosening and, therefore, cell expansion. Recently and ERF transcription factor was cloned that is highly up-regulated duing submergence and functional studies are on their way. Complementary research on natural variation for flooding tolerance in Arabidopsis is currently conducted to identify novel genetic regulators of tolerance.


2. Shade avoidance and plant competition
Plants often grow in dense vegetations in nature, leading to severe competition for resources, such as light. Shade avoidance response help plants to escape from shade imposed by neighbors and we study how these responses are regulated at the physiological and molecular level. Our current understanding is that multiple signals, including changes in blue light and the red:far-red light ratio inform a plant about the presence of neighbors. These signals activate GA-dependent degradation of DELLA proteins, growth repressing transcriptional regulators and stimulate auxin biosynthesis and auxin transport towards epidermal cells where growth is probably controlled. Current studies also use our mechanistic insights to predict and unravel interactions between shade avoidance and other forms of plasticity to respond to alternative environmental challenges, such as pathogen and herbivore attack.

For more information, contact Rens Voesenek (email)