高等植物共质体区内与区间的电波传递

本文以白花紫露草(Tradescantia flumi—nensis Vel)为材料,运用胞外、胞内微电极及显微注射等方法,对电波在植物体内的传递方式进行了进一步探讨。结果表明,白花紫露革对于伤害性刺激可以产生强烈的电位波动在周身传递。这种电位波动可以被FAA固定液造成的生理障碍阻断;白花紫露草叶片可分为不同的共质体区,在共质体区内,电波传递很快,远高于液相中物质的扩散速度;而在各共质区问,电波传递出现时间上的延迟,与共质体内电波传递速度相差一个数量级,因此,可以推测,在共质体区内电波是以局部电流的方式传递的,而在共质体区问,电波的传递可能有化学介质的参与。

Electrical Wave Transmission Within and Between Symplastic Regions in Higher Plants

Depending upon the excitability ofthe treated plants, a local burn mayinitiate various modes of electricalwave (EW) transmission, which canbe variation wave (VW), action wave(AW), or their composite, and attimes the sustaining EW pulsations.Diverse opnions exist, however,about how EW transmissions are car-ried through out the plant. The presentinvestigation approaches the problemby engaging Tradescantia fluminensis asexperimental material, and by employ-ing extra-- and intra-cellular electrodesand microinjection of membrane--im-permeable dyes as probes. If a segmentof the stem is treated with FAA fixa-tive beforehand, the burn--induced EWtransmission, which is conducted pref-erentially through parenchyma in thevascular system, fails to traversethrough such a physiological block, in-dicating that regardless of VW or AW,living activties of the conducting tissueare involved in transmission. Microin-jections of membrane-impermeable flu-orescent dye LRG into individual cellsof vascular parenchyma, mesophyll,or epidermis reveal that the dye couldbe transported promptly in the varioustissues, but not so readily betweenthem. There seem to exist distinctsymplastic regions, among which thesymplastic pathway or the plasmodes-mata are open to traffic, yet the per-meability between tissues of differentregions are relatively low. Intra--cellu-lar electrode measurements show thatEW transmission takes place readilyalong the 1ongitudinal sequence in thetissue of the same symplastic region,whereas a time lag exists in the trans-verse EW transmission between tissuesof different symplastic regions.