Ethylene and Ethane Production in 2,4-D Treated and Salt Treated Tobacco Tissue Cultures

Abstract

Gas chromatography was used to measure ethylene (ethene) and ethane production by tobacco (Nicotiana tabacum cv. Wisconsin no. 38) callus tissues grown on media containing inorganic salts according to Murashige and Skoog (1962), sucrose, myo-inositol, thiamine-HCl kinetic according to Linsmaier and Skoog (1965), and either 2,4-dichiorophenoxyacetic acid (2,4-D) in the range 0–100 mgl−1 or 2 mgl−1 indoi-3-ylacetic acid plus NaCl in the range 0–200 Meq l−1. Ethylene production rates were high (> 500 nl h−1 g1− fresh weight) initially in all treatments. Subsequently, ethylene production declined in rapidly growing cultures but remained high in moderately and severely 2,4-D (> 0·5 mgl−1) stressed and in severely NaCl (≥150 Meql−1) stressed cultures. High initial rates of ethane production (> 200 nl h−1 g−1 fresh weight) were obtained under conditions of severe stress caused by 2,4-D or NaCl but not in control or moderately inhibited cultures. With further incubation ethane production declined in the severely stressed cultures. It is concluded that ethylene production can be used as an index of moderate 2,4-D stress and severe NaCl stress by virtue of the high persisting rates of ethylene production in stressed cultures. Ethane production can be used as an early index of severe stress caused by either 2,4-D or NaCl in vitro.