Perception and realization of gravistimulation in protonema of mosses

1Lesnyak, Yu.I, 1Demkiv, OT
1Institute of Ecology of the Carpathians of the National Academy of Sciences of Ukraine, L’viv, Ukraine
Kosm. nauka tehnol. 2005, 11 ;(3-4):120-123
Publication Language: Ukrainian
The protonema of mosses perceives and realizes gravistimulation by apical cells of stolones. The function of gravireceptors is executed by amyloplasts, which are sedimentcd on the bottom part of я lateral side under ihe influence of gniviiatioii. The character of distribution of amyloplasts- and dynamics of scdimcniaiion are described for different kinds of mosses. Nevertheless, the processes of transduction of gravistimulation in growth process remain unexplored. II is experimentally shown that in conditions of low temperatures the perception of gravistimulation takes place, but the growth of apical cells is blocked. When gravisiimulate prolunela are transferred to natural conditions of environment, gravitropic bend is realized. It is estahlished that the realization of gravistimulation can he experimentally blocked by inhibitors: of calcium's canals by verapamils with a concentration of 10-4 and 10-3 M and calcium's pumps by ortovanadats nalriums with a concentration of 10-5 to 10-4 M. Exogenous phytohormones of indole-3-acetic acid (IAAJ) and α-naphthyl acclate- acid (NAA) with a concentration of 10-7 and 10-4 M influenced insignificantly growth and gruvltropir bend of apical cells of protonema. Nevertheless, phylotropin NPA with a concentration of 10-4 oppressed considerably gravitropic- dependent bend and scarcely affected growth rate of apical cells of protonema
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