Contrasting effects of ethylene perception and synthesis inhibitors on GA3-induced antheridiogenesis and the level of 1-aminocyclopropane-1-carboxylic acid in Anemia phyllitidis gametophytes

In Anemia phyllitidis gametophytes two of the ethylene perception inhibitors (silver ions, Ag+; 2.5-norbornadiene, NBD) caused opposite effects on GA(3)-induced antheridia formation and on the increment of ACC (1-aminocyclopropane-1-carboxylic acid) content accompanying this process. Ag+ enhanced while NBD inhibited GA(3)-induced antheridiogenesis and each inhibitor modulated the level of ACC in a different manner. Cobalt ions (Co2+) and aminooxyacetic acid (AOA; the ethylene synthesis inhibitors), also modulated the level of GA(3)-induced ACC content differently. These results strongly confirm the earlier suggestion that ethylene plays a role of the second messenger in GA(3)-induced antheridiogenesis during "induction" and "expression" phases. and the 3rd h of the former phase is the time when elevation of ACC content induced while in the 6th h inhibited antheridiogenesis. Timing of changes in ACC content and morphogenetic effects of GA(3)-induced antheridiogenesis in A. phyllitidis gametophytes allowed to indicate that AOA together with NBD could participate in one while Co2+ and Ag+ in another ethylene synthesis and signaling pathway. (c) 2009 Elsevier B.V. All rights reserved.