1) Vypracování literární rešerše na téma mechanismů vlivu prospěšných mikroorganismů na růst rostlin a úloha MAPK signalizace při interakci rostlin s prospěšnými mikroorganismy. 2) Fenotypová analýza transgenních linií vojtěšky (Medicago sativa) při interakci s prospěšnými mikroorganismy rodu Enterobacter podmínkách in vivo. 3) Imunohistochemické studium lokalizace MAPK u vojtěšky při interakci s prospěšnými mikroorganismy.Alfalfa (Medicago sativa) is an allogamous legume from the family Fabaceae. It is typically used as cattle feed, diet supplement, drug additive and common material for ethanol production. Enterobacter is a gram-negative rod-shaped bacteria, which is regularly located inside the intestines of mammals. The bacteria tend to keep a symbiotic relationship with alfalfa, therefore it is classified as a plant-growth-promoting microorganism (PGPM). Enterobacter provides the plant with nitrogen, phosphorus and iron, it helps the plant in defense against phytopathogens and enhances the resistance of plant against abiotic stresses from the environment. For communication with the host plant, bacteria use a specialized mitogen-activated protein kinase (MAPK) cascade, called stress-induced MAPK, SIMK, which is activated via salt stress and elicitors. Changes in SIMK regulation can cause alteration in the alfalfa root phenotype, therefore SIMK became the target of interest for biotechnological improvements in alfalfa cultivation. The aim of this work was to analyze the phenotype of alfalfa cultivar Regen SY (RSY), transgenic lines SIMK RNAi, SIMKK RNAi and the GFP-SIMK after inoculation with bacteria Enterobacter sp. SA187 under in vitro and ex vitro conditions. The in vitro analysis focused on the growth of the root system and the ex vitro analysis focused on the alfalfa above-ground fresh and dry weight and shoot length and numbers. Using the immunofluorescence method, the localization of SIMK and phosphorylated MAPKs in alfalfa root-tip cells was also observed. Using the immunofluorescence method, the localization of SIMK and phosphorylated MAPKs in alfalfa root cells was observed.