GENETICKY MODIFIKOVANÉ ROSTLINY ODOLNÉ K SUCHU A ZASOLENÍ.

During their evolution, plants have developed a number of mechanisms to resist biotic and abiotic stressors. Evolution is an endless process, which continues, of course, even today. In the case of crop plants, however, evolution's original contingency is replaced by targeted breeding. This is based on the same natural processes - mutagenesis, hybridization and selection. However, the classical techniques are now significantly complemented by genetic engineering methods. Based on knowledge of the molecular basis of plant stress resistance mechanisms, these processes are subsequently used to obtain new, practically- useful genotypes. The present paper is therefore aimed at explaining the biological effects of drought or salinity from the molecular level to the complex reactions of the whole organism. Subsequently, the paper illustrates various opportunities for using transgenic techniques (gene modifications, GM) for the construction of crops resistant to these stressors, explains their gene background and illustrates, in selected examples, both the history of partial research strategies, their present status and also their prospects. In addition, the paper briefly informs about a new technique of gene editing (GE) based on the mechanisms of natural repair of the plants' own genes. This precise mutagenesis has also found practical, revolutionary, applications both in human gene therapy and in effective "nature-close" breeding and plant protection. [ABSTRACT FROM AUTHOR]