The role of phytohormones in the battle for yield: prospects and possible dangers



In the rapidly developing biotechnological world, microorganisms are rapidly adapting to existing pesticides. In order to cope with this problem, more active interaction between scientific, industrial and educational institutions is required. Former Deputy Minister of Economic Development, Trade and Agriculture of Ukraine Inna Dmitrievna Meteleva in an interview with the newspaper "Agroobrazovanie" focused on how important the "education - science" connection is in terms of training new generation professional personnel.



The National University of Bioresources and Nature Management of Ukraine (NUBiP) has been at the forefront of innovative solutions in the field of biotechnology for several years. One of the most promising developments of the University, which has undergone practical testing both in laboratory conditions and in the fields of the arid zone of the Zaporozhye region, is based on the research of the authors of the Department of Agricultural Soil Science and Agrophysics at NUBiP Buchek Polina Vladimirovna and Zabaluev Vladimir Alekseevich. Scientists have analyzed the interaction of microorganisms with the rhizosphere of plants (called mycorrhiza). The preparation "Mikoplant", created by P. Buchek and V. Zabaluev, consists of spores and vesicles of the fungus of the Glomus family, presented in the form of a root granular substrate. The principle of action is that the plant secretes phytohormone rhizolactone,which promotes the symbiosis of fungi with the root system and strengthens mycorrhiza. Especially in the arid regions of our country, this is very important, where the root system of plants is poorly developed and the rhizosphere is also poorly developed, as a result of which a small amount of water is absorbed.



Another similar study was carried out by T. P. Pirog, G. A. Iutinskaya, N. O. Leonova, K. A. Beregovaya and T. A. Shevchuk from the Institute of Molecular Biology and Genetics (IMBiG). Scientists treated plant seeds with the phytohormone strigolactone. In the experiment, good results were obtained and seeds treated with phytohormone sprouted quickly, and adult plants had a powerful root system. When compared with the control, the rhizosphere of plants not treated with phytohormone was about 2 cm, and the rhizosphere of experimental plants expanded to 1.5 meters.



A plant releases a very large number of phytohormones. They can be roughly divided into 3 parts: stem phytohormones - auxins, root phytohormones - cytokinins, leaf phytohormones - gibberellins.



C. Darwin suggested for the first time that plants secrete biologically active substances that affect their growth and development. He described an experiment studying the apical zone of the stem. Scientists noticed that the plant always tends to the sun, being in the shade, the stem "bends" and crawls to the source of sunlight. An experiment was conducted to establish which part of the plant gives a signal to form this bend. First, Darwin covered the bending zone so that sunlight could not enter this area, but the plant still wriggled and bent towards the light. After that, he covered the crown of the stem, and the plant stopped bending. Then Charles Darwin suggested that some molecules are produced on the top of the plant, the activity of which leads to physiological changes and regulates the process of stem bending. Following,what the researcher did was test his theory: he cut off the apex and the plant stopped bending. Well, the last thing Darwin did was to place the cut off crown in a Petri dish with agar. Then he cut out a piece of agar and placed it on the cut off place of the apex - the plant began to bend. This is how the first phytohormone in history, auxin, was identified and described.



As it turned out, all phytohormones have an attracting effect, with the help of which it is possible to "deceive" the plants, increasing their productivity. For example, by treating the strawberry fruit with auxin, you can achieve large fruits, but there is a flip side of the coin. The fruit grows intensively and consumes sugar for growth, so such strawberries are less sweet. Also, if you do not calculate the dose of auxin, then you can simply achieve the opposite effect, and the plant will die. This pattern was noticed by lovers of the "beautiful lawn" and now in Europe a lawn treated with auxin consists exclusively of monocotyledonous plants, since dicotyledonous plants die from large doses. The lethal effect of massive doses of auxin was used by the US Armed Forces during the Indochina War. Due to the fact that the Vietnamese partisans were hiding in the rainforests,it was decided to spray Agent Orange over the rainforests of the Mekong Delta. This has had enormous implications for both the flora and fauna of the region. In animals and humans, skin diseases arose, leading to systemic organ damage and oncological diseases.



Cytokinins, hormones that cause cell division, deserve a separate mention. If the plant is treated with cytokinins (phytohormones of the roots), the plant receives a signal that the root system needs glucose. Photosynthesis occurs in the leaves of plants, therefore, having received such a signal, the leaves begin to work intensively, producing glucose (nutrition for all living organisms). Or the fetus, having received such a signal, remains green for a long time and does not age. Of course, nature could not take advantage of this. There are a lot of animals (nematodes, for example), fungi (actinomycetes, for example) that are capable of producing cytokinins. In nematode larvae, for example, cytokinins are produced in the salivary glands. By eating leaves, it forms galls and, being in the middle of these galls, receives more glucose from the plant. Well, a few words about the Gebberellins.Gebberellins are phytohormones that accelerate the flowering process.



In general, we can say that phytohormones and possible areas of their application are invariably in the field of interest of scientists and the close attention of researchers.



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