Method for quantitative determination of phytohormones in plant tissues

The review analyzes and summarizes information on the history of development and the current state of methodological approaches to the qualitative and quantitative determination of phytohormones in plant tissues. Plant hormones play an indispensable role in many physiological processes during a plant life cycle, from seed’s germination to senescence. The determination of the endogenous hormones concentration is essential for elucidating the role of a particular hormone in any physiological process. A sensitive and quick analytical method of a simultaneous quantitative estimation of the main classes of phytohormones is essential for the investigation of signaling control networks in specific developmental pathways and physiological responses. In plant tissues, phytohormones are present in very low concentrations (from 10-9 M to 10-6 M); hence, the availability of highly effective, comprehensive and reliable analytical techniques for their identification is extremely important. The article gives a brief description of the main classes of plant hormones and outlines their functional activity. The importance of methods for hormones identification in plant tissues and their use in plant physiology and agricultural practice is discussed. The study presents a valid and tested sequence of procedures for the extraction of plant hormones, a methodology for purification of the obtained extracts from interfering substances and an up-to-date method of plant hormones quantification (indole-3-acetic, abscisic, gibberellic, salicylic acids and five forms of cytokinins). The quantification method combines a high-performance liquid chromatography with a mass spectrometry. Four chromatographic methods for the sepa­ration and detection of substances in aliquots as well as ionization conditions for hormones in a mass spectrometer are described. The presented analytical technique is adapted for scientific laboratories in Ukraine.