A discovery of gravisensitivity of plant cells specialized and not specialized to gravity perception stimulated the intensive research of cell biology in altered gravity. In order to better understanding of the possible mechanisms of this phenomenon, it is proposed to distinguish between cell gravisensing and graviperception. It is assumed that proliferative and actively metabolizing cells are the most sensitive to the influence of altered gravity. Grounded on the hypothesis of gravitational decompensation, the consequences of events occurring in plant cells under the microgravity action are discussed. Prospects of future research in this field are proposed.