The Interplay Between Stress and Auxin during in vitro Embryogenesis
The positive relationship between stress and in vitro embryo induction is well documented. Plant growth regulators, in particular the synthetic auxin and herbicide 2,4-D, are also potent inducers of plant cell totipotency. On the one hand, treatment with 2,4-D at non-herbicidal concentrations induces a stress response, characterized by increased ethylene and ABA biosynthesis, while on the other hand it also stimulates endogenous auxin production. A large body of circumstantial data suggests that both a stress response and an auxin response are required for the switch to totipotent development. Our current hypothesis is that in vitro embryogenesis is a two-step process comprising i) a stress-related event that is needed in the early phase for genome reprogramming to embryo development, followed by ii) an endogenous auxin-related event that is required for cell proliferation. How different stress treatments are transduced to generate an endogenous auxin response is one of the key questions of this research. In this project, we will combine molecular biology, cell biology and organic chemistry approaches to answer this question, using two model in vitro embryogenesis systems, heat-stressed induced microspore embryogenesis in Brassica napus and 2,4-D-induced somatic embryogenesis in arabidopsis.
Funding: NWO Building Blocks of Life; project number 737.016.013
Start date: 01-09-2017
End date: 01-01-2022
Kim Boutilier (WUR), Charlotte Siemons (WUR), Gerco Angenent (WUR), Omid Karami (Leiden University), Remko Offringa (Leiden University), Hana de Jong (Utrecht University), Tom Wennekes (Utrecht University)
A. Horstman, M. Bemer and K. Boutilier. (2017). A transcriptional view on somatic embryogenesis. Regeneration 4:201–216.
A. Horstman, M. Li, I. Heidmann, M. Weemen, B. Chen, J. M. Muino, G. C. Angenent and K. Boutilier. (2017). The BABY BOOM transcription factor activates the LEC1-ABI3-FUS3-LEC2 network to induce somatic embryogenesis. Plant Phys. 175: 848-857.
W. Grunewald, H. S. Robert, M. Sauer, B. Cannoot, M. Soriano, R. Swarup, D. Weijers, M. Bennett, K. Boutilier and J. Friml. (2015). Plant embryogenesis requires AUX/LAX-mediated auxin influx. Development 142: 1-10.
M. Soriano, H. Li, C. Jacquard, J. Krochko, G. C. Angenent, R. Offringa and K. Boutilier. (2014). Plasticity in cell division patterns and auxin transport-dependency during in vitro embryogenesis. Plant Cell 26:2568-2581.
M. Soriano, H. Li and K. Boutilier. (2013). Microspore embryogenesis: establishment of embryo identity and pattern in culture. Plant Reprod. 26:181-196