[Chemical signaling in plant microspore cells]

Chemical signal transduction from the cell surface to organelles was studied in unicellular vegetative (Equisetum arvense) and generative (Hippeastrum hybridum pollen) microspores of plants. Neurotransmitters acetylcholine, dopamine, and serotonin, their agonists and antagonists, Na+, K+, and Ca2+ channel blockers, as well as forskolin and theophylline (agents increasing the intracellular level of cyclic adenosine monophosphate) were used as chemical signals. Both types of microspores exposed to neurotransmitters, their agonists, forskolin, and theophylline demonstrated growth activation, while neurotransmitter antagonists and ion channel blockers inhibited this process. No stimulating effects of neurotransmitters were observed for cells pretreated with the antagonists and ion channel blockers. Pretreatment with ion channel blockers and then by anticontractile agents (cytochalasin B or colchicine) either had no effect or increased the inhibition of microspore growth. Pathways of chemical signal transduction from the cell surface to organelles are discussed.