Oxygen concentration and ethylene production in roots and leaves of wheat: short term reaction in air after anoxic and hypoxic treatments.

Seven-day old wheat seedlings (Triticum aestivum L. cv. MEC) were incubated in small jars, fluxed with gas mixtures of nitrogen-oxygen (oxygen concentrations 0, 0.3, 1, 2.5, 10%) for up to 48 h. Effects of anoxia and hypoxia on ethylene evolution and ethylene-forming enzyme (EFE) activity were determined 1 h after the plants had been transferred to air, respectively. 1-aminocyclopropane-1-carboxylic acid (ACC) content was measured immediately after treatments. Results showed that the ethylene production is differently affected by oxygen deprivation in roots and leaves. The effects are more closely related to ACC accumulation than to the EFE activity. In leaves, ethylene evolution is almost unaffected by oxygen concentrations above ca 1%. [ABSTRACT FROM AUTHOR]