Сlinorotation is an effective method of treating diseases caused by some plant viruses. Therefore, we researched the influence of microgravity (modeled by сlinorotation) on a tobacco mosaic virus (TMV) that infects many agricultural crops. It is known that cells of plants (infected with TMV) contain viral inclusion bodies or viroplasms and amount of viral inclusion bodies correlates with harmfulness of TMV. Therefore, the purpose of this study was to find out the effect of influence of modeled microgravity on inclusion bodies of TMV. In this study, we cultivated Nicotiana tabacum L. and inoculated them with TMV that was isolated from Norway maple (Acer platanoides L.). Then we divided these plants into two groups and cultivated these plants under normal and microgravitation conditions. Microgravity conditions were modeled by сlinorotation at 2 rpm for 4 hours a day. This experiment lasted 36 days. Changes of the amount of TMV inclusion bodies in cells of plants that cultivated under normal and microgravitation conditions was investigated by luminescence microscopy. We found that formation of TMV inclusion bodies under microgravitation conditions is first slowed down compared to formation under normal conditions and then their amount quickly decreasing. These results demonstrate the gravisensitivity of TMV. It was suggested hypothesis that this viroplasm pattern caused by the disorganization of cortical microtubule-associated ER sites (C-MERS) that are nodes of cellular transport pathways and nucleation centers of cortical microtubules and cortical microfilaments. It is known that under microgravity conditions there is a disorganization and disorientation of cortical microtubules, which stabilize C-MERS on which TMV viroplasms are formed. Thus, the disorganization and disorientation of cortical microtubules probably causes the disorganization of C-MERS, which leads to a decrease in the number of TMV viroplasms under the influence of microgravity. In this context, it is worth noting that some plant viruses, such as a Wheat streak mosaic virus (WSMV), a Potato virus M (PVM) and Potato curly dwarf virus (PCDV), are gravisensitive. These viruses belong to different taxa, for example WSMV belong to genus Tritimovirus (family Potyviridae), PVM belong to genus Carlavirus (family Betaflexiviridae) and PCDV belong to plant rhabdoviruses (uncertain taxonomic position), and differ both structurally and functionally. Therefore, the gravisensitivity of these viruses can occur by other mechanisms. Thus, antiviral therapeutic effect of clinorotation based on gravisensitivity of TMV and can be used in the production of virus-free seeds. To confirm this hypothesis, it is necessary to conduct a systematic review, as well as experimentally establish the fact of the disorganization of the C-MERS under microgravity conditions.

Aim. To investigate the direct and indirect impact of clinorotation on vital activity of gilled mushrooms (Agaricales) using the mycelium of the model organism Agaricus bisporus, clinorotated by the ground-based facility Ekoloh, as the example. Methods. The mycelium of Agaricus bisporus was cultivated on the medium with agar and compost extract. The microgravitational environment was simulated using the method of uniaxial clinorotation at the ground-based facility Ekoloh. The mycelia of Agaricus bisporus from the experimental group were clinorotated for 4 h a day for 12 days. The samples from the control group were cultivated in normal (1 g) conditions. The simulated gravitational acceleration value was 3.5 × 10–4 g at the rotational velocity of 2.5 rpm and the rotation radius of 0.05 m. The centrifugal acceleration, affecting the mycelium of Agaricus bisporus under clinorotation, was 0.00343 m/s2. The two-way ANOVA analysis demonstrated that the effects of g-level, the duration of the impact and their interaction were all statistically signifi cant. At the same time, 73.1 % of the variance in mycelium growth coeffi cient was triggered by the simulated value of the g, i.e. the duration of the impact was a minor factor. Results. Clinorotation stimulated growth and development of gilled mushroom (Agaricales) mycelium. In particular, in this study the clinorotated mycelium of Agaricus bisporus had approximately 3.4, 2.5, 1.6 times higher coeffi cients of mycelium growth compared against the mycelium, cultivated in stationary conditions (1 g) on day 5, 10, and 15 of the cultivation respectively. Contrary to the control mycelial colonies, the growth of clinorotated mycelial colonies of Agaricus bisporus was asymmetric. The direction of the gravitational acceleration vector regarding mycelium colonies was constantly changing in the microgravitational environment, simulated by the ground-based facility Ekoloh. At the same time, different organs of Agaricus bisporus are characterized by gravitropism of different orientation. Therefore, constant changes in the direction of gravitational acceleration vector regarding mycelium could have caused constant re-orientation of mycelium cells in terms of the gravitational acceleration vector, and thus, multidirectional asymmetric growth. In addition, the centrifugal acceleration, generated during clinorotation, is a mechanostimulator, capable of triggering stress responses in different living systems. The accelerated growth is one of the stress responses. At the same time, mycelium could expand in the environment mechanically due to the impact of centrifugal acceleration. However, the centrifugal acceleration was insignifi cant, thus, we believe that the main effect was caused by microgravity. Conclusions. Since clinorotation stimulates the growth and development of gilled mushrooms and is an effi cient way of forming virus-free planting material of different plants, this technology may have a wide scope of application. It may be used in agriculture, forestry and different industries, using raw plants or mushrooms, for instance, in food, pharmaceutical and textile industries, etc.