## 1 Introduction  
Contamination of soil is one of the most severe current environmental issues. A wide range of chemical compounds has been contaminating soil resources for a couple of centuries with industry development, intensification of agriculture, and other human activities. Heavy metals, petroleum hydrocarbons, pesticides and solvents were identified as the most common ones. These contaminated areas may affect ecosystems' functions, and they can cause several health problems [1]. On the other hand, with proper decontamination management, some of these sites represent non-food agronomy production opportunities. Growing energy crops in different marginal lands is a very actual topic because of limited sources of good quality agricultural soil [2]. One of the promising biomass production plants in contaminated sites is _Miscanthus x giganteus_ (_Mxg_) [3]. This C4 perennial grass can tolerate high concentrations of heavy metals in soil without significant uptake of metals to shoot part [4; 5; 6; 7]. It has low nutritional content requirements in soil [8], fertilization and pesticides [9]. Additionally, it can improve soil parameters with an increase of soil carbon content [10] and soil microbial communities [11]. Together with these environmental benefits, good shoot biomass yield and biomass parameters are suitable for different processing methods [9; 12; 13; 14; 15; 16]. The behaviour of _Mxg_ grown in metals-contaminated soils has already been intensively studied in recent years [4; 5; 7; 17; 18; 19], but only several studies were carried out with _Mxg_ growing in soils contaminated with organic pollutants. [PERSON] et al (2011; 2012a, b) described _Mxg_ tolerance in PAH contaminated soil (364 \(\pm\) 59 mg/kg PAH with pyrene as the main compound) and production of root exudates which could be involved in the biostimulation of PAH-utilizing soil bacteria. [PERSON] et al. [20] tested _Mxg_ ability to grow in soil contaminated with organochlorine pesticides (DDT and HCH and their metabolites and isomers) with good results at the first growing season (specific values of biomass have not been reported). According to our knowledge, there are no published data about the possibility of using _Mxg_ in soils contaminated dominantly by aliphatic petroleum hydrocarbons, one of the most abundant contaminants of soils because of improper transport storage of fuels, petroleum industry activities or accidents [21; 22]. External conditions, such as contamination, can play an important role in plant internal processes, resulting in change of fitness and potentially in decrease of biomass yield [23; 24]. That could significantly decrease phytomanagement effectiveness or even disable its realization. One of the most vulnerable processes is the primary plant process, photosynthesis. It has been reported before that abiotic stress can influence the photosynthetic activity of higher plants. Photosystem II (PSII) plays significant role in the primary phase. Unfortunately, its key components, proteins D and D2 are sensitive susceptible to certain types of stress [25; 26]. Together with the sensitivity of chlorophyll, systems of primary photosynthetic phase are perfect targets to study response of plants to abiotic stress. In this study of non-destructive method of leaf fluorescence measurement was used, taking advantage of chlorophyll \(a\) fluorescence kinetics [27; 28; 29; 30; 31]. It was combined with the determination of leaf anatomy changes by microscopy to explore _Mxg_ stress response in different contaminants. Another focus of this study was on the state and development of soil microbial communities and their stress response in contaminated soils during the experiment. Soil microorganisms play a key role in soil health and the hydrocarbons degradation process. Therefore, the potential positive effect of _Mxg_ on soil microbial communities could be significant for the overall improvement of soil quality and for the following research in organic compounds phytoremediation.