Tari I, Szabó A
Department of Plant Physiology, József Attila University, Szeged, Hungary.
Acta Biol Hung. 1990;41(4):387-97.
Roots of plants growing "aeroponically" (AP) on moistened filter paper in Petri dishes for a few days are fairly often used for physiological experiments (e.g. measurement of root growth), for ion or herbicide uptake tests, before the establishment of hydroponic or aseptic cultures although their hormonal status is markedly different from that of the hydroponic (HP) control. On the 4th day of germination the ethylene production of cucumber (Cucumis sativus L. cv. Budai csemege) roots growing in AP under controlled conditions increased considerably and exhibited a maximum curve, HP roots evolved ethylene much more constantly. The morphological changes in AP roots (e.g. inhibited elongation and swelling of primary roots, and increased formation of root hairs), resembling those caused by exogenously applied ethylene, can be prevented with 10(-5) M Ag+, an inhibitor of ethylene action. In roots of one-week-old AP seedlings, the amount of an acidic inhibitor, which as judged from the Rf values is likely to be abscisic acid (ABA), is about twice as high as in HP seedlings. An elevated ethylene or ABA level of AP roots may result in a reduced elongation of the primary roots. Counteraction of this inhibition by Ag+ suggests that the effect of ethylene is the primary event in the reduction of root length. When using plant material grown in Petri dishes the possibility of similar changes in hormonal status of the roots must be taken into consideration.
在培养皿中湿润滤纸上以“气培法”（AP）生长几天的植物根系，尽管其激素状态与水培（HP）对照明显不同，但在建立水培或无菌培养之前，相当常用于生理实验（如根系生长测量）、离子或除草剂吸收测试。在发芽第4天，在受控条件下气培生长的黄瓜（Cucumis sativus L. cv. Budai csemege）根系的乙烯产量大幅增加并呈现出最大值曲线，而水培根系释放乙烯则更为稳定。气培根系的形态变化（如主根伸长受抑制和肿胀，以及根毛形成增加）类似于外源施加乙烯所引起的变化，可用乙烯作用抑制剂10(-5) M Ag+来防止。在一周龄气培幼苗的根系中，一种酸性抑制剂的含量，根据Rf值判断可能是脱落酸（ABA），约为水培幼苗中的两倍。气培根系中乙烯或ABA水平升高可能导致主根伸长减少。Ag+对这种抑制作用的抵消表明，乙烯的作用是根长减少的主要原因。当使用在培养皿中生长的植物材料时，必须考虑根系激素状态发生类似变化的可能性。
