Allelopathy Journal

The chemosignaling in allelopathy uses plant microspores as unicellular models. Possible mechanisms were compared for pollen and vegetative microspores. Development of pollen (generative microspores) from knights’ star (Hippeastrum hybridum) and vegetative microspores of Equisetum arvense were analyzed after treating with blockers of ion channels and anticontractile agents for 24 h (short-time experiments) and 25–28 days (long-time experiments). The blockers of Na⁺, K⁺, Ca²⁺ ion channels (relatively α-bungarotoxin; tetraethylammonium; verapamil) or anti-conractile agents (cytochalasin B or colchicine, except papaverine or clofelin), depressed the germination (30–60% in short-time exposures) of both types of microspores to different degrees depending on the concentration. Moreover in longtime experiments, the normal fruits were not formed from the pollens after pollination, while, in vegetative microspores the gamethophyte (thallus) and antheridia (male sexual organs) formation were inhibited. However, the actin from rabbit muscle, restored the vegetative microspore germination after the blockade of cholinoreceptor (related to Na⁺/K⁺ channels) by α-bungarotoxin or the intracellular binding with cytochalasin B, inhibitor of actin polymerization. The similar effects were observed in preliminary blockade of Ca ²⁺ channels with verapamil in pollen of knights’ star. Thus, the pathways of chemosignal transduction from the cell are discussed in relation to possible mechanism of allelopathy.