A completely new mechanism that allows plants to form vascular tissue for the efficient transport of water and nutrients was published today in the prestigious scientific journal Science. Scientists from CATRIN at Palacký University and the Growth Regulators Laboratory, a joint workplace of the Institute of Experimental Botany of the Czech Academy of Sciences and the Faculty of Science at Palacký University, also participated in the research led by the University of Cambridge and the University of Helsinki. The study paves the way for future research to optimize the growth characteristics of crops important to agriculture and forestry, including the production of commercially valuable materials such as wood, paper, and bioproducts.
“This research clarifies how plants finely tune the development of vascular tissues and determine the fate of their vascular cells. The findings may influence plant traits ranging from drought resistance to root and tuber growth in food crops to wood formation,” said co-first author Raili Ruonala from the University of Helsinki.
Based on studies of a model plant Arabidopsis thaliana, scientists have uncovered the regulatory dynamics that control xylem formation. This conductive tissue acts as the plant’s “water supply,” distributing water and minerals upward while helping to strengthen the plant. The experts then focused on thermospermine, a small positively charged polyamine molecule already known to regulate vascular cell differentiation. It turned out that the fate of some plant cells in the vascular system depends on the cooperation of two factors – thermospermine and a specific chemical modification of the ribosome – the cell’s “protein factory.” The study showed that only ribosomes carrying a specific chemical “mark” on their RNA allow thermospermine to bind properly and subsequently control cell development.
Members of the CATRIN research team have also focused on polyamines as plant growth regulators in their research into plant responses to stress. Polyamines help plants grow better and cope with stress, or, for example by influencing which genes are switched on or off in a cell and how proteins are produced. Scientists have now shown that these molecules can also directly regulate ribosomes, defining cell differentiation and development.
“These findings are significant because they are the first experimental evidence of this mechanism. In addition, polyamines are synthesized by all living organisms, which is why this research is important not only for plants but also for other organisms, including human health,” said co-author Nuria De Diego, head of the CATRIN Plant-Environment Interactions research group. Together with her colleague Sanja Ćavar Zeljković, they were responsible for measuring polyamines. They are collaborating with the University of Helsinki, the University of Cambridge, and the Polish Academy of Sciences to use this discovery to understand secondary tree growth and study certain diseases.
Ondřej Novák, the head of the Laboratory of Growth Regulators, participated in He participated in the characterization of plants with a mutation in a gene whose activity is influenced by the chemical modification of ribosomes after binding with thermospermine. “The study provides the first evidence that a polyamine can directly and specifically regulate gene expression directly at the ribosome. Detailed structural analysis further reveal precisely how thermospermine binds. The research thus uncovers a new regulatory principle and resolves a mystery known for more than 15 years. Namely, how thermospermine can activate or suppress different groups of genes as needed, but only through a ribosome with a specific chemical label,” said Novák.
Although the research was conducted on the model plant Arabidopsis, it suggests that the same signaling may occur in other plants. For example, in trees, these signals could be set to promote the formation of many conductive vessels for upward growth, while in radishes, they could be adjusted to favor storage cells in the root, allowing the plant to store more energy.
Scientists from Olomouc collaborated on the research with colleagues from the United Kingdom, Finland, Spain, Denmark, Sweden, Poland, and other countries.