Scientists discover a previously unknown plant mechanism — and its impact could be massive

Scientists find that meiotic exit in Arabidopsis Driven by inhibition of translation mediated by P-body

Albert Cairo, Karel Reha and their colleagues discovered a previously unidentified mechanism for reprogramming gene expression during the transition when cell to cell differentiates. The mechanism occurs at the conclusion of meiosis, a specialized cell division required for sexual reproduction, and allows germ cells and pollen grains to differentiate.

This mechanism involves the dynamic localization of essential regulatory components in intracellular condensate resembling liquid droplets. This process is directly related to seed production and may provide new ways to generate more sustainable crops that can withstand harsh environmental conditions. The results were recently published in the prestigious journal Sciences.

Field caterpillar flower captured by light microscope. Credit: Central European Institute of Technology – Masaryk University

Cells are not static things. They change from one type to another. Activation of a particular set of genes affects how cells specialize in completing specific tasks and when they divide or differentiate. Cell biologists such as Albert Cairo and Karel Reha use a range of cutting-edge scientific methods to explore the exact world of plants. Cell biology is currently undergoing a revolution, with the traditional perspective of cell organization being extended to new heights.

“We now know that the cell contains not only conventional, membrane-defined organelles but many molecular processes are confined within less membrane-specific organelles, also called biomolecule condensers (biocapacitors). During the past 10 years, the importance of these biocapacitors has begun to be recognized.” We are now contributing to this field by showing how a specific type of biocondensation forms at the end of meiosis and inhibits protein synthesis,” explains Albert Cairo, first author of this research.

“This, on the one hand, ends the processes of meiosis, but on the other hand, it marks the beginning of a genetically different generation of cells,” Cairo adds. but that is not all. The research team believes that similar mechanisms are also at work in other organisms and cellular settings, including cell differentiation or stress responses.

The discovery by members of Karel Riha’s lab could have an enormous societal impact.

Albert Cairo and Karel Riha. Credit: Central European Institute of Technology – Masaryk University

“We are living in a climate emergency. Although plants can withstand a wide range of stresses, including high temperatures and drought, their growth and reproduction can be severely impaired. This means that we are in danger of a significant reduction in crop yield, only when the yield has to be increased to meet human needs. This is why plant research should now be a priority,” explains corresponding author and research group leader Karel Riha.

The laboratory’s primary task is to shed light on the basic biological processes closely related to plant reproduction and seed formation, which in many crops translate into yield.

The research results show that biomolecular condensers play an important role in plant fertility, and their behavior is likely related to environmental stress. So it is clear that our discovery is the first step in developing new solutions that lead to sustainable crop production under extreme conditions,” explains Albert Cairo.

The technical techniques the team had to do are really impressive, and this research was published in Sciences Rest assured that the Reha Laboratory is heading in the right direction.

The road to discovery

Study of meiosis in a model plant Arabidopsis thaliana It is a particular challenge. The research team focused on rare and unusual cells hidden in tiny 0.1-0.4 mm flower buds. Moreover, the phases of the meiotic division on which the study is focused occur quickly – the whole process takes from five to six hours. Therefore, it is not easy to catch it. The research team must use the latest technology and a good deal of creativity and imagination to explore this process.

Riha’s team had to set up conditions for live imaging of meiosis within the other organ (the part of the stamen that contains the pollen). The team used advanced microscopy and became one of two laboratories in the world able to directly monitor plant meiosis. Another piece of core expertise the team gained was mastering the protoplast technique. Protoplasts are isolated plant cells that have been deprived of their surrounding cell wall, making them easy to genetically manipulate and visualize under a microscope. This technique allowed the team to clear some issues more quickly and efficiently than using meiotic cells.

Anna Vargova has made a significant contribution to the understanding of the newly described complex mechanism. Pavlina Mikulkova provided expertise and lent her magic hand during live cell imaging of meiosis using a Light-shit microscope. The research team was supported by the CEITEC CELLIM Core Facility and the Plant Science Core Facility. The research took over eight years and was funded by the REMAP Youth and Sports Scholarship Project of the Czech Ministry of Education. “It would be very difficult to develop such a complex project without the long-term funding that we had. In fact, at some point, I felt like our limits were just our imagination, and I think that was crucial to our long-term discovery,” says Albert Cairo.

Reference: “Meiotic Exodus in Arabidopsis Driven by P-body-mediated inhibition of translation by Albert Cairo, Anna Vargova, Neha Shukla, Claudio Capitao, Pavlina Mikulkova, Sona Valuchova, Jana Pecinkova, Petra Bulankova and Karel Riha, 4 August 2022, Sciences.
DOI: 10.1126 / science.abo0904

Interestingly, this project did not include any external collaboration, which is unusual for international research institutes such as CEITEC. In this case, the research team was entering a completely new direction and the research was concluded exclusively by members of Karel Riha’s research group.