Throughout their life, plants form leaves and side roots. These two types of organs have something in common: their development is finely tuned by small regulatory RNA molecules, the trans-acting short interfering RNAs (ta-siRNAs). Scientists Dr. Alexis Maizel and Virginie Jouannet at Heidelberg University‘s Centre for Organismal Studies were able to demonstrate how and where within the plant cell these ta-siRNAs are produced. They succeeded in identifying hotspots for the biogenesis of these special RNA molecules. The results of this study have been published in the “EMBO Journal”.
On the left, a normal mouse-ear cress (Arabidopsis) plant, and on the right a plant in which ta-siRNA formation is compromised. The leaf structure of the plant is abnormal. Credits: Alexis Maizel, Virginie Jouannet
The formation of plant organs depends on the presence of proteins that allow cells to divide and take on new shapes and characteristics. The most straightforward route to protein production begins when genes are activated and transcribed into messenger RNAs that are then translated into proteins. However, cells often fine-tune their population of proteins by producing short interfering RNAs (siRNAs): small regulatory molecules that dock onto messenger RNA and cause them to be broken down before they can be used for protein production. Researchers already knew that ta-siRNAs, a type of siRNA, fine-tune the formation of leaves and the growth of side roots by blocking the production of specific proteins. What remained unknown, however, was exactly where in the plant cell the ta-siRNAs were produced.
Ta-siRNAs are created from longer RNA molecules that are whittled down by a complex of other molecules. One essential component of this cutting machine is a protein called AGO7. The Heidelberg scientists have uncovered that AGO7 accumulates in foci, called siRNA bodies, located in the cytoplasm of the cells. SiRNA bodies also contain all the other enzymes needed for the formation of ta-siRNAs. “These foci are therefore hotspots for the formation of the siRNAs, that is the small, regulatory RNA molecules”, explains Virginie Jouannet, a PhD student in Dr. Maizel’s group. In addition, the researchers were able to show that AGO7 could not longer fulfil its functions when released from the siRNA bodies, resulting in problems in the development of the plant.
Two other observations caught the attention of the researchers. For one thing, the siRNA bodies are closely linked to the network of membranes that the cell uses to transport and secrete proteins. “Interestingly, these foci also host viruses and plants defend themselves against viruses using siRNAs”, says Dr. Maizel. “These results reveal a hitherto unknown role for membranes in the biogenesis of RNA and suggest that the generation of siRNA can occur only in specific locations of the cell.”
Dr. Maizel leads an independent research group at the Centre for Organismal Studies at Heidelberg University and is a member of the university’s CellNetworks Cluster of Excellence. Collaborating on the research project were scientists from the Institut des Sciences du Végétal at the Centre National de la Recherche Scientifique (CNRS) in Gif-sur-Yvette as well as the Institut Jean-Pierre Bourgin at the Institut National de la Recherche Agronomique (INRA) in Versailles (France).
For information online, see http://www.cos.uni-heidelberg.de/index.php/independent/a.maizel?l=_e
Marietta Fuhrmann-Koch | idw
Tag it EASI – a new method for accurate protein analysis
20.06.2018 | Max-Planck-Institut für Biochemie
How to track and trace a protein: Nanosensors monitor intracellular deliveries
19.06.2018 | Universität Basel
In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.
Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...
Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
20.06.2018 | Materials Sciences
20.06.2018 | Materials Sciences
20.06.2018 | Materials Sciences