Inhibition of photosynthesis by ethylene

Little is known about how the plant hormone ethylene influences plant growth, except that it probably affects a fundamental control system. Research with inhibitors of ethylene binding and action has significantly expanded the level of understanding of the hormone. While CO2, an inhibitor of ethylene binding, has been studied extensively1,2 the effect of ethylene on CO2, metabolism in photosynthesis has been virtually ignored. An initial communication indicated no photosynthetic response to ethylene by either Pisum sativum L. or Zea mays L.3, but the exposure and the number of species tested were extremely limited. We therefore made a more extensive examination of the relationship between photosynthesis and ethylene. We report here a pronounced and reversible effect of hormonally significant levels of ethylene on the photosynthesis of the peanut.