Water deficit and salt stress are two major environmental stresses for plants. Salt decreases crop yield and as soil salinity increases worldwide, this causes a problem for agriculture. Luckily, plants can adapt their growth to environmental conditions. In our lab, we are investigating the responses of plants to salinity stress and water deficit from different angles.
The most easily visible changes in plant growth occur above ground, but the first contact with salt happens between the soil and the root system. Research in our lab has shown how flexible this root system is and how it reshapes during salt stress. Our lab discovered that the main root can change direction when it encounters salt, a process called halotropism. Data from our lab also showed that there are different strategies of reshaping root architecture in response to salt. These different strategies result in a different ratio of lateral and main root length. But how are plants able to alter their growth, how do they sense the salt and what are the implications for salt tolerance?
Many thanks to Dutch Science Foundation NWO (both fundamental and applied science domain projects), CSC, ERA-Net, Nuffic and ERC-Consolidator (Sense2SurviveSalt) for supporting our research.
The research continues with these questions:
How is root architecture remodeled during salt and water stress and how do root responses to salt contribute to stress tolerance of plants?
How are Na+ ions sensed by plants? What is the molecular mechanism that sets in motion all downstream responses that are mounted when plants encounter salinity?
How is the balance between cellular Na+ and K+ levels maintained in the presence of an overwhelming amount of Na+ ions during salt stress?
What is the role of auxin transport and local auxin biosynthesis and conjugation in root and shoot developmental responses to salt stress?
What are the gene regulatory networks that guide developmental responses to salt and water stress?
Our lab uses approaches that include natural variation screening and genetics, stress physiology, gene editing, mutant screening, cellular microscopy, and biochemical approaches. To screen stress physiology, we have developed a time-lapse imaging system that can continuously measure the differences in growth. The species we work on: Arabidopsis (of course!), tomato, the halophyte S. parvula, and potato.
Do you want to see our techniques in real-life and are you interested in how we use programming in our research? Listen to PhD student Iko explain techniques and programming in dutch:
A selection of our publications:
- Korver, R. A., Koevoets, I. T. & Testerink, C. Out of Shape During Stress: A Key Role for Auxin. Trends Plant Sci. 1–11 (2018)
- Arisz, S. A. et al. Diacylglycerol acyltransferase 1 contributes to freezing tolerance. Plant Physiol. (2018).
- Julkowska, M. M. et al. Genetic Components of Root Architecture Remodeling in Response to Salt Stress. Plant Cell 29, 3198–3213 (2017).
- Van der Does, D. et al. The Arabidopsis leucine-rich repeat receptor kinase MIK2/LRR-KISS connects cell wall integrity sensing, root growth and response to abiotic and biotic stresses. PLoS Genet. 13, e1006832 (2017).
- van den Berg, T., Korver, R. A., Testerink, C. & Ten Tusscher, K. H. W. J. Modeling halotropism: a key role for root tip architecture and reflux loop remodeling in redistributing auxin. Development 143, 3350–62 (2016).
- Koevoets, I. T., Venema, J. H., Elzenga, J. T. M. & Testerink, C. Roots Withstanding their Environment: Exploiting Root System Architecture Responses to Abiotic Stress to Improve Crop Tolerance. Front. Plant Sci. 7, 1335 (2016).
- Julkowska, M. M. & Testerink, C. Tuning plant signaling and growth to survive salt. Trends Plant Sci. 20, 586–94 (2015).
- Julkowska, M. M. et al. Identification and functional characterization of the Arabidopsis Snf1-related protein kinase SnRK2.4 phosphatidic acid-binding domain. Plant. Cell Environ. 38, 614–24 (2015).
- Julkowska, M. M. et al. Capturing Arabidopsis root architecture dynamics with ROOT-FIT reveals diversity in responses to salinity. Plant Physiol. 166, 1387–402 (2014).
- Galvan-Ampudia, C. S. et al. Halotropism is a response of plant roots to avoid a saline environment. Curr. Biol. 23, 2044–50 (2013).