Evidence that thermoinhibition and the alleviation thereof by oxygen plus kinetin in Great Lakes lettuce seed is related to mitochondrial function

Abstract

Thermoinhibition of Lactuca sativa L.cv. Great Lakes 659 seeds occurred at 36 ˚C. Thermoinhibition was alleviated by a combi­nation of 100% O₂ and kinetin (10 mg dm⁻³). Chloramphenicol nullified the effect of O₂ plus kinetin. A number of mitochondrial activities (respiration, coupling, certain matrix enzyme activities and incorporation of [³⁵S]- methionine in mitochondrial proteins) were lower in thermoinhibited than in seeds imbibed at 25 ˚C. Treating seeds with plus kinetin at 36 °C restored these mitochondrial activities to the same or in some cases, to higher levels than in 25 °C control seeds.