Growth Regulation by Ethylene in Fern Gametophytes. II. Inhibition of Cell Division

Abstract

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(2-Chloroethyl)phosphonic Acid Promotes Germination of Immature Spores of Ceratopteris richardii Brongn.

“…In 0. sensibilis ethylene does not affect imbibition of water by spores but effects inhibition of spore germination prior to DNA synthesis, nuclear migration and cell division (4,6). Inhibition is overcome by light and appears related to photosynthesis and not phytochrome (3,5).…”

Carbon Dioxide and Ethylene Control of Spore Germination in Onoclea sensibilis L

“…The latter situation could be inhibitory to spore germination. Experimental conditions of the data reported here involved 2-liter chambers, but often experiments with fern gametophytes are conducted in chambers with much smaller volumes in which accumulated CO2 may be influential (6)(7)(8). Previously, when the effects of ethylene were investigated, the possible involvement of CO2 with experimental cultures was not considered.…”

“…Although ethylene was demonstrated to be inhibitory to cell division and spore germination in ferns (6,7), the particular effect of CO2 on spore germination was not investigated previously. The present study was undertaken to determine the influence of CO2 and ethylene on the light-dependent germination of Onoclea spores.…”

“…One of the first determinations of the effect of ethylene specifically at the cellular level was with Onoclea gametophytes: cell division in different stages of gametophytic development, both protonemal and prothallial, is reduced by ethylene (6,14). Germination of unicellular Onoclea spores also is inhibited by ethylene (7).…”

“…Examples of the latter phenomenon include fern protonema (14), aquatic species of angiosperms (10,17), and mesocotyl tissues of oats and rice (16). When applied to rice seedlings (13) or to Onoclea protonema (14), ethylene promotes cellular elongation, although in the later prothallial stage of Onoclea, the ethylene promotion is absent (6). In some aquatic plant systems, combined ethylene-CO2 treatment not only stimulates tissue elongation, but ethylene and CO2 are synergistic (17).…”