Inhibition of ethylene production by osmotic shock. Further evidence for membrane control of ethylene production

Effects of osmotic shock applied to mung bean hypocotyl segmentswere examined to see if auxin-induced ethylene production isregulated by membrane activity. Uptake of -aminoisobutyric acidwas significantly inhibited by osmotic shock. While cold shockalone also inhibited the uptake, cold osmotic shock was mosteffective. Auxin-induced ethylene production by the osmoticallyshocked tissue was similarly inhibited. Shock treatment of auxin-pretreatedtissue also suppressed the subsequent ethylene production. Oxygenuptake was not affected by the shock treatment. Sorbitol andsucrose used as osmotic substance were as effective as mannitol.The results suggest that ethylene production is controlled bymembrane activity. (Received July 18, 1977; )