Drought is one of the major stress factors affecting the growth and development of plants. In this context, drought-related losses of crop plant productivity impede sustainable agriculture all over the world. In general, plants respond to water deficits by multiple physiological and metabolic adaptations at the molecular, cellular, and organism levels. To understand the underlying mechanisms of drought tolerance, adequate stress models and arrays of reliable stress markers are required. Therefore, in this review we comprehensively address currently available models of drought stress, based on culturing plants in soil, hydroponically, or in agar culture, and critically discuss advantages and limitations of each design. We also address the methodology of drought stress characterization and discuss it in the context of real experimental approaches. Further, we highlight the trends of methodological developments in drought stress research, i.e., complementing conventional tests with quantification of phytohormones and reactive oxygen species (ROS), measuring antioxidant enzyme activities, and comprehensively profiling transcriptome, proteome, and metabolome.

Drought is one of the major stress factors affecting growth and development of plants. In this context, drought-related losses of crop plant productivity impede sustainable agriculture all over the world. In general, plants responses to water deficit by multiple physiological and metabolic adaptations at the molecular, cellular and organism levels. To understand the underlying mechanisms of drought tolerance, adequate stress models and arrays of reliable stress markers are required. Therefore, in this review we comprehensively address currently available models of drought stress, based on culturing plants in soil, hydroponic or agar culture. These experimental setups give access to different aspects of plant response to drought, like decrease of tissue water potential, reduction of stomata conductance and photosynthesis efficiency, accumulation of low-molecular weight solutes (metabolic adjustment) and drought protective proteins. Till now, this pattern of markers was successfully extended to the methods of enzyme chemistry, molecular biology and omics techniques. Thus, conventional tests can be efficiently complemented by determination of phytohormone and reactive oxygen species (ROS) contents, activities of antioxidant enzymes, as well as comprehensive profiling of transcriptome, proteome and metabolome.

Introduction. Metabolic activation of xenobiotics, including pharma drugs, is considered to be one of the main mechanisms for the development of idiosyncratic reactions. Accordingly, the potential bioactivation of a xenobiotic should be carefully evaluated in the early stages of drug development. In this regard, the search for new rapid and effective screening techniques for reactive metabolites of xenobiotics presents particular interest.Objective. Development of a new technique for modeling the processes of xenobiotic biotransformation in vitro to identify potential metabolites of indapamide.Materials and methods. Non-enzymatic instrumental methods, such as electrochemical oxidation (ECO) and photocatalytic oxidation (PCO) in volume, were used as comparison methods. The second phase of metabolism was modeled by incubating the oxidation products of indapamide with a trapping agent (glutathione, GSH). The oxidation products, as well as their conjugates with GSH, were then analyzed by high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). The developed one-pot technique for metabolism modeling is based on a UV-induced PCO of a xenobiotic in the presence of GSH on the surface of a target functionalized with titanium dioxide followed by detection of the products by matrix-assisted laser desorption/ionization mass spectrometry (MALDI).Results. In use of ECO resulted in the detection of 5 metabolites and 3 adducts with GSH, while the use of PCO in the volume allowed detection of 7 metabolites and 1 adduct with GSH. The new one-pot technique detected 8 adducts with GSH. In addition to the detection of a number of known indapamide metabolites and their conjugates with GSH, a total of 4 previously unstudied metabolites and adducts with GSH were each detected for indapamide by the three methods.Conclusions. In comparison with ECO and PCO in volume, the proposed analytical technique for modeling indapamide metabolism showed its higher informativity combined with simplicity and rapidity, which makes it a promising candidate for use in preclinical studies of drugs in predicting the metabolism and toxicity of pharmaceutical objects, as well as in studying the biotransformation processes of various xenobiotics.