The Highly Cited Researchers 2020 list of the 6,200 most cited scientists from more than 60 countries also includes the name of plant hormone analysis expert Ondřej Novák from the Laboratory of Growth Regulators – a joint workplace of the UP Faculty of Science and the Institute of Experimental Botany of the Czech Academy of Sciences.
Together with his colleagues, Ondřej Novák tries to clarify the irreplaceable role of phytohormones in the functioning of plants. The results of joint research by Olomouc scientists are finding applications in agriculture, cosmetics, and in the research of anticancer substances.
How do you feel about being ranked on the list of the world’s most cited researchers?
I feel much obliged to be placed in the list of highly cited researchers for the third time and at the same time, very pleased. This is a list of the most cited scientists, pioneers in their fields over the last decade, who represent over 1250 institutions. But it’s not just my personal success – it is also an appreciation of the work of my students, colleagues and collaborators from our university and the Czech Academy of Sciences.
What do you do in the Laboratory of Growth Regulators?
We focus on plant hormones, which are small signalling molecules that are responsible for how a plant will respond to various external stimuli and how it will develop. Plant hormones are responsible, for example, as to whether a plant is growing correctly in the light or its roots are spread out enough to effectively draw water and nutrients from the soil. To put it simply – in our team we try to determine the plant hormones in plant tissue to better understand how plants work internally. At our workplace, we focus on plant hormones from the point of view of analytical chemistry, because I am an analytical chemistry graduate although I specialise in biology (my doctorate is in botany).
What results can be achieved by studying phytohormones and their function in plants?
Thanks to the study of plant hormones, it is possible e.g. to map the mechanisms by which plants respond to external stress stimuli. For example, how they cope with higher salinity of the surrounding environment, drought or, conversely, excessive moisture. We can find out how the organism of the plant identifies the situation when e.g. there is a drought for five days. Thanks to phytohormones, the plant responds to this by stopping its growth in order to reduce its moisture requirements. All these processes are controlled at the level of signalling pathways. The plant hormone elicits a response whether the plant establishes another leaf, or prefers to form another lateral root to obtain more moisture.
What is the role of the plant hormones in this complex system?
Through phytohormones, information is shared that the plant lacks nutrients and must find some other way to their source. For example, a group of phytohormones called auxins is responsible for establishing a new root. But we do not know yet what the signal is that initiates this complex process. We only know that the plant will establish the root and which cells will be divided during this process. We also don’t know why the root of the plant is being established in a specific place, and not e.g. five centimetres lower. In our research, we therefore try to fit these individual fragments of the mosaic together to understand the functioning of the entire system.
What methods do you use to study these complex processes inside plants?
To do this, we need the tools of molecular biology. So we use different transgenic plants and mutants. We work at the level of genes and DNA, we cut out different parts of DNA. We also perform classical biochemical analysis, which we use to determine events at the level of metabolism. We focused our attention on a narrow group of very important molecules – plant hormones, which, however, are very few. Just to give you an idea – there are millions of molecules in one cell, but in our research we study only one percent of that number. These signalling molecules, called phytohormones, play a key role in how a plant will grow.
What is the most common practical use of your knowledge?
We are developing methods for the determination of small signalling molecules, i.e. phytohormones. Subsequently, we use these methods in collaboration with plant biologists in basic research. The acquired knowledge can later be applied, for example, in agriculture and biotechnology, which has been a huge trend recently. Thanks to the research into phytohormones, it is possible to reduce the amount of chemicals used in agriculture, such as pesticides and herbicides. Our aim is to reduce the burden on the environment by means of special preparations that function at the level of plant signalling molecules, by regulating their concentration or influencing their biological effect. For example, we often analyse products that are used in agriculture. We monitor whether they contain signalling molecules – phytohormones – which they should contain, if we expect that the plants will have, for example, greener leaves due to the application of the product. We determine phytohormones in biostimulants, which are now very popular in organic farming. Or we try to understand why the given product supports the formation of the root system. We also often examine the result of what the plants produce after application of the product and whether the product in question really promotes the biosynthesis of the desired signalling molecules.
What other applications do phytohormones have in the field of plant cultivation?
They have wide applications. Virtually everyone will encounter plant hormones, because we all buy flowers from time to time. In flower growing, the widely used method is biotechnology, where phytohormones are important in cloning. Thanks to this, the flowers sold are the same in Olomouc, Prague, or Paris. This applies not only to roses, but also to cuttings and houseplants. In addition, in this way are multiplied not only economically important, but also endangered medicinal plant species.
How do flower achieve this effect?
It all starts in the something called a “flowbox” with a nutrient medium, to which, in addition to sugars, vitamins, macro- and microelements, phytohormones are added at a certain stage. First to be mixed in is cytokinin, which is responsible for the formation of stems and leaves. Thus, the above-ground part of the plant will grow, especially a large number of new shoots, and therefore also seedlings. Then auxin, which is in charge of rooting, is added. As a result, the plant creates enough roots and grows to the desired shape. This is how it works in biotechnology as standard. Despite it sounding very simple, these are complicated protocols that are difficult to finetune for individual plant species.
What will be the direction of your further research?
The Laboratory of Growth Regulators is a workplace that is an example of multidisciplinarity. This means that we are somewhere in the middle of the intersection between plant physiology and applied chemistry, and between medical research and biotechnology. My colleagues celebrate successes in the field of chemical biology. This is the interconnection of organic chemistry, which is the basis of all methods or applications that are used in the field of drugs, cosmetics, or biostimulants. In our team, we study phytohormones in depth. We are not only interested in the signalling molecules themselves, but in the complex metabolism of plant hormones and the way they work. I think that as one of the few workplaces in the world, we can analyse all the fragments that make up a complex metabolism for each of the eight hormonal groups. In the past 20 years, we have managed to put together individual methodological approaches that are functional and interconnected. At present, we are trying to focus more on the plant cell itself and the events hidden in it. In the field of plant hormones, we can relatively easily see how the metabolism of these substances works at the level of the whole plant. However, the processes inside the cell are a huge unknown, something we still don’t know that much about yet. Therefore, we are gradually moving to the level of the cell to observe what happens there with phytohormones. It’s a huge challenge, because the cell is very small. It could be compared to the head of a pin, looked down upon from a cosmic height. But we are already working on it and we know the direction to go. It is not only an interdisciplinary connection, but also cooperation with other scientific teams at the top international level. And so we’re back to the Highly Cited Researchers ranking, where my name could never have been found without cooperation with other colleagues.
The Highly Cited Researchers 2020 list includes approximately 6,200 researchers from more than 60 countries working in or across 21 research areas. These are personalities whose work has had a great impact on the scientific community and have been extraordinarily cited. The prestigious list also includes 26 Nobel Prize winners. The ranking includes a total of four scientists associated with Palacký University. In addition to Ondřej Novák, chemists Rajender Varma, Radek Zbořil, and Patrik Schmuki are also there. The list for 2020 was based on an analysis of publications from 2009 to 2019 according to Clarivate Analytics’ Web of Science database.