КАЛЛУСООБРАЗОВАНИЕ И КАЛЛУСОГЕНЕЗ IN VITRO У ЗЛАКОВ: РОЛЬ ГОРМОНАЛЬНОГО БАЛАНСА

Abstract

The most difficult fundamental problem of plant development biology remains morphogenesis as the totality of cell differentiation processes occurring in a developing organism with the formation of specialized tissues and organs. Prospective experimental systems in this field of research are callus cultures in vitro. The callus is an integrated system formed both exogenously (as a result of the proliferation of surface cells of various tissues of the plant organism) and endogenously (in the depth of these tissues); initially consists of homogeneous cells, gradually transformed into a system of groups of heterogeneous cells with species-specific morphogenetic potencies, which are realized by various ways of morphogenesis, some of which leads to the formation of plants. Sufficient empirical material has been accumulated to study the effect of various exogenous factors (mainly hormones) on the induction of callus formation from different explants and the callusogenesis in vitro, however, contradictory results have been obtained. In addition, the important question of the ratio of endogenous hormones (as part of the explant/callus), which play the role of signals from the internal environment, and exogenous hormones (as part of the inductive/regenerative medium), which play the role of signals from the external environment, in the induction of callus formation and callusogenesis in vitro, has not been sufficiently studied. This article presents the brief overview of the literature and own data obtained in the study of hormonal features both in callus formation induction and callusogenesis in vitro in cereals. The wide range of physiological activity of hormones and the successes achieved with their help in realizing the morphogenetic potential of callus cells in vitro are emphasized. The relationship between the hormonal status of explants/calli and their ability to morphogenesis in vitro is shown. The methodological approach consisting in the identification and use of the optimal balance of endogenous (as part of the explant/callus) and exogenous (as part of the inductive/regenerative medium) hormones makes it possible to make the process of callusogenesis in vitro controllable.