Researchers have demonstrated how auxin, a hormone that controls many processes in plants, reaches its destination
A team of researchers from the University of Freiburg have discovered how the plant hormone auxin is transported within the cell and how this signaling pathway helps to control gene expression in the nucleus. Auxin regulates many processes in plants: from embryonic development, to the development of organs, all the way to responses to changes in the environment. The team recently published its research in the journal Cell Reports.
According to current scientific models, auxin works with other proteins to fulfill its function. When auxin content in the nucleus rises, receptors bind in the presence of auxin repressors, initiate repressor degradation and enable auxin responsive transcription factors to trigger gene expression. Because it is believed that auxin content in the nucleus is important for this, the researchers focused on how auxin gets into the nucleus and how this process is controlled.
The researchers from the University of Freiburg therefore collaborated with colleagues from Munich and Okayama, Japan, to test new, fluorescent, auxin-mimicking molecules in single cells. These molecules allowed them to visualize the accumulation of auxin in the cell without triggering any auxin-related processes. They were thus able to demonstrate that the auxin-mimicking molecules accumulated primarily in the endoplasmic reticulum (ER), which is a system of flat tubules that is a continuation of the nuclear membrane directly connected to the nucleus.
Next, the team studied how the ER, nucleus, and other cell parts work together to absorb auxin in the nucleus. Because there are currently no adequate methods of directly measuring the transport of auxin between the cell’s different compartments, the researchers developed a combined experimental-theoretical approach that allows them to use a combination of microscopy, quantitative data analysis, and mathematical modeling to observe how individual plant cells react to different auxin levels. Based on the results of their research, they concluded that the flow of auxin from the ER to the nucleus represents an important signaling pathway within the cell to regulate auxin levels in the nucleus, and hence in supporting processes triggered by auxin.
The team of researchers includes Dr. Cristina Dal Bosco, Dr. Alexander Dovzhenko, and Prof. Dr. Klaus Palme, all from the Department of Molecular Plant Physiology of the Institute of Biology II, as well as Dr. Alistair Middleton and Prof. Dr. Christian Fleck, both from the Center for Biological Systems Analysis (ZBSA) at the University of Freiburg. Dr. Palme is also a member of the cluster of excellence BIOSS Centre for Biological Signalling Studies.
Middleton, A. M., Dal Bosco, C, Chlap, P, Bensch, R., Harz, H., Ren, F., Bergmann, S., Wend, S., Weber, W., Hayashi, K., Zurbriggen, M.D., Uhl, R., Ronneberger, O., Palme, K., Fleck, C., Dovzhenko, A. (2018): Data-driven modeling of intracellular auxin fluxes indicates a dominant role of the ER in controlling nuclear auxin uptake. Cell Reports.
Prof. Dr. Klaus Palme
Institute of Biology II
University of Freiburg
Phone: +49 (0)761/203 - 2954
The hormone auxin controls many processes in plants. Source: Institute of Biology II/University of Freiburg
Rudolf-Werner Dreier | Albert-Ludwigs-Universität Freiburg im Breisgau
Complete skin regeneration system of fish unraveled
24.04.2018 | Tokyo Institute of Technology
Scientists generate an atlas of the human genome using stem cells
24.04.2018 | The Hebrew University of Jerusalem
At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.
Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...
Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.
Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
24.04.2018 | Information Technology
24.04.2018 | Earth Sciences
24.04.2018 | Life Sciences