Plant tissue culture environment as a switch-key of (epi)genetic changes

The in vitro tissue cultures are, beyond all difficulties, an essential tool in basic research as well as in commercial applications. Numerous works devoted to plant tissue cultures proved how important this part of the plant science is. Despite half a century of research on the issue of obtaining plants in in vitro cultures, many aspects remain unknown. The path associated with the reprogramming of explants in the fully functioning regenerants includes a series of processes that may result in the appearance of morphological, physiological, biochemical or, finally, genetic and epigenetic changes. All these changes occurring at the tissue culture stage and appearing in regenerants as tissue culture-induced variation and then inherited by generative progeny as somaclonal variation may be the result of oxidative stress, which works at the step of explant preparation, and in tissue culture as a result of nutrient components and environmental factors. In this review, we describe the current status of understanding the genetic and epigenetic changes that occur during tissue culture. Variation appeared in regenerated plants as well as variation inherited by generative progeny of regenerants can may many, positive or negative impact, of gained plant materials. This review focused on factors that triggered this phenomenon with underlying oxidative stress.