Ca^2＋载体A23187对烟草生殖核分裂的调节

用Ｃａ＾２＋载体Ａ２３１８７研究了高钙水平对烟草离体花粉管内生殖核分裂的影响。结果表明，Ａ２３１８７抑制花粉管生长，影响其正常形态，调节生殖核分裂，较高浓度Ａ２３１８７可阻断生殖核分裂，而较代浓度的效应因处理时间而异；萌发６ｈ处理显著抑制生殖核分裂。

REGULATION OF GENERATIVE NUCLEUS DIVISION BY CALCIUM IONOPHORE A23187 IN NICOTIANA TABACUM POLLEN TUBES

The effects of high calcium on Tabacco generative nucleus (GN) division were studied using calcium ionophore A23187. Mature pollen grains were artificially germinated ina medium containing 10-3 mol/L calcium ions. A23187 of various concentrations wasadded at 2, 6, 10 and 14 h respectively.Then pollen tubes (PT) were sampled at intervals,measured in length and stained with fluorescent dye DAPI for investigating the dynamics of GN division rate. A23187 could inhibit PT growth,affect PT form and regulateGN division.The influence of A23187 on GN division was related to the mitotic phase ofGN and the drug concentration.The higher concentrations (10-6 mol/L and 10-5 mol/L) blocked GN division completely no matter when the treatment was carried out,whereas the lower concentration (10-7 mol/L) showed different effects on GN divisiondepending on the time when A23187 was applied.The application of 10-7 mol/L A23187at 6 h of culture inhibited the increase of GN division rate significantly, but showedchangeable effects in 10 h and 14 h treatments from initial promotion to later inhibition.Moreover,the drug at the higher concentrations also had a dramatic effect on GN form,resulting in its rounding. The mechanism of how hith calcium regulates GN division wasdiscussed.