钙在6-BA诱导黄化绿豆幼苗下胚轴原生质体体积膨大中的作用

ROLE OF CALCIUM IN 6-BA-INDUCED SWELLING OF PROTOPLASTS ISOLATED FROM HYPOCOTYL IN ETIOLATED MUNG BEAN SEEDLINGS

对照和仅用6-BA(无Ca^(2+))处理的原生质体的体积均无变化。含钙培养液中的原生质体经6-BA处理后10min^(45)Ca^(2+)积累明显增多,15min后开始膨大;处理30min时^(45)Ca^(2+)积累最多,此时原生质体的膨大效应最好;随后^(45)Ca^(2+)积累和膨大效应逐渐下降。两者的时间进程十分相似。K^+、Zn^(2+)、Ba^(2+)、Mg^(2+)等可在不同程度上代替Ca^(2+)的作用。EGTA、verapamil和LaCl_3处理均可使原生质体^(45)Ca^(2+)累积降到对照的水平,膨大效应完全消失。表明Ca^(2+)可能在6-BA诱导原生质体膨大的过程中起着重要作用。

This paper studied on the role of calcium in 6-BA-induced swelling of protoplasts isolated from hypocotyl in etiolated mung bean(Phaseolus radiatus L. ) seedlings. Protoplasts incubated in CaCl2-bearing medium without hormone maintained a constant volume. To treat with 6-BA, they began to swell after 15 minutes,and continually swelled to the maximum volume 30 minutes later when they were treated with 10-6mol/L 6-BA(Fig. 2). However,the protoplasts could not swell when 6-BA was added into the medium without CaCl2(Fig. 1). It was suggested that Ca2+ was necessary for 6-BA to induce protoplast swelling. 6-BA enabled the protoplasts to swell in less extent when K+ ,Zn2+ ,Ba2+ or Mg2+ instead of Ca2+ (Fig. 3). Radioisotope experiments showed that K+ influx increased when Ca2+ was replaced by K+ (Fig. 4). 45Ca2+accumulation in protoplasts treated by 6-BA was much higher than that of control, and the time course of 45Ca2+ accumulation was similar to protoplasts swelling (Fig5). 45Ca2+level and the swelling of protoplasts were sharply declined when EGTA,verapamil or LaCl3 was added into the medium (Table 1,2 and 3). These results indicated that Ca2+may play an important role in 6-BA-induced swelling.