Aim. The main aim of the study was to analyze the effect of microgravity on the growth and development of Arabidopsis thaliana seedlings at different time intervals of cultivation (4–10 days) and to investigate the development of autophagy induced by the conditions of microgravity in seedlings root cells. Methods. Microscopic methods as well as in vitro propagation method were used. To simulate of microgravity conditions plants were placed in clinostat machine. Results. In the course of experiments, the peaks of the formation of autophagosome were recorded: in the cells of the root cap zone of at 9th day and in the cells of the root zone extension on the 10th day of clinical establishment. Conclusions. It can be concluded that microgravity is capable to induce the development of autophagy in the roots of A. thaliana seedlings. Cells with signs of autophagy were revealed on the 9th and 10th day of cultivation of seedlings under microgravity conditions.
Keywords: Arabidopsis thaliana, autophagy, microgravity.
Аутофагія є еволюційно консервативним клітинно-біологічним механізмом деградації та рециркуляції нутрієнтів і макромолекул, що забезпечує виживання клітин за несприятливих умов. Саме тому процеси аутофагії задіяні в підтримці гомеостазу клітин, формуванні зародка, проростанні насіння, утворенні провідних тканин ксилеми, старінні листків і захисті від патогенів [1]. Деградація пошкоджених органел та білкових агрегатів відбувається завдяки функціонуванню літичних структур клітини. Для цього реалізація механізмів аутофагії передбачає формування двомембранних молекул-аутофагосом, які достав-БІОЛОГІЯ
It was shown that clinostating conditions induce autophagy without increasing of programmed cell death (PCD) index in the epidermal cells of the root apex of A. thaliana seedlings. After the phase of activation of autophagy, its regulatory weakening occurs, which probably indicates adaptive changes to the conditions of clinostating. The induction of autophagy correlates with an increase in the expression levels of atg8 genes, some of which (atg8e and atg8i) may be involved in the implementation of autophagy under the simulated microgravity conditions. The transcriptional activity of cytoskeleton genes involved in the implementation of stress-induced autophagy, in particular α- and β-tubulin genes, was analyzed. Joint expression of α- and β-tubulin genes and atg8 under the simulated microgravity conditions was revealed. These results illustrate the role of the cytoskeleton in the development of microgravity-induced autophagy and make it possible to identify genes specific to this type of stress. The induction of autophagy and PСD was studied under the action of gamma irradiation as a concomitant factor of space flights, as well as under the combined action of acute irradiation and clinostating. Gamma irradiation in doses equivalent to those in the spacecraft cabin (1 - 6 Gy) induced dose-dependent changes in the topology and cytogenetic state of the root apical meristem, as well as slightly inhibited of the early plant development. In the meristem, heterogeneity increased, PCD indexes, mainly proliferative death and autophagy, increased. With the combined action of gamma irradiation (2 Gy) and clinostating, the density of autophagosomes in the epidermal cell root apices of 6-day-old seedlings increased (24 hours after irradiation), and after 4 days it decreased, compared to the non-irradiated control.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.