Scientists Develop Method of Detailed Investigation of Phytohormones
Another important piece of the puzzle in the recognition of plant hormones called cytokinins was revealed by scientists from the Laboratory of Growth Regulators, which is a joint project of the Faculty of Science at Palacký University and the Institute of Experimental Botany of the Academy of Sciences of the Czech Republic, and the Centre of the Haná Region for Biotechnological and Agricultural Research. They have developed a methodology that allows them to investigate in more detail than ever before these hormones in root cap cells. The results of three-year-long research have been recently published in the renowned scientific journal The Plant Cell.
New methods were created by Olomouc experts together with their colleagues from Sweden and the United Kingdom on the basis of the model plant Arabidopsis thaliana, or thale cress. It may also be applied on other plants, including agricultural crops. Scientists used modern technology including flow cytometry and mass spectrometry with high sensitivity to separate the root cells of thale cress and analyse the content of cytokinins in the cells of individual tissues. This allowed them to be the first ones who have reached the zeptomolar concentration level (10-21). While normally biologists have to work with at least milligram samples of plant material with millions of cells, now it suffices to select “only” 20 to 200 thousand cells originating from the same tissue.
“We have developed a very sensitive detection system. The huge shift lies in the fact that now we’re able to study small populations of cells coming from a specifically defined type of tissue and measure extremely low concentrations of phytohormones. We have also confirmed that the root cap contains the concentration gradient of cytokinins, which has been known only about auxins up to now,” said one of the authors of the study, Ondřej Novák from the Laboratory of Growth Regulators. Such an in-depth analysis of cytokinins has never been conducted before.
In addition to that, scientists have acquired new information concerning the system of cytokinin metabolism and degradation in the roots of plants. “These findings should help us better understand the principle of how the root cap functions in the process of growth and development of the whole root. Experts today seem to incline to the notion that the root cap significantly affects plant development by means of phytohormones. And we have found out which cytokinins are there and how they work. Further research will discover what it means for the plant and how to use these findings in practical applications,” added Novák.
According to him, this achievement has been made possible due to very patient and unyielding work of the researchers. They used hundreds of thousands of plants during hundreds of experiments and cell isolations. “One single analysis requires 3000 plants of Arabidopsis, and the analysis needs to be repeated up to ten times. In order to obtain the information about the whole root cap, we needed to have 150,000 plants at our disposal. It is quite unique, in fact, that we were able to achieve these results. We believe that development of other top-notch technologies will make it possible to further improve our method, and most importantly, minimise it,” said Novák.
Arabidopsis is an important model plant species, often used in molecular biology for its simplicity and low demands in cultivation. Arabidopsis also fulfils other conditions imposed on model plants – a small genome, short recovery time between two generations, and sufficient offspring. It is one of the most widespread model plants in biology laboratories. Its genome sequence was completed at the turn of the century; the very first one.