DEVELOPMENT OF PIGMENT SYSTEM IN BARLEY SEEDLINGS UNDER HYPOBARIC HYPOXIA

Accumulation of chlorophylls and carotenoids in the course of greening is studied in etiolated barley (Hordeum vulgare L.) seedlings exposed to white light under hypobaric hypoxia. The amount of chlorophyll and carotenoids synthesized under hypobaric hypoxia was reduced compared with plants at normal atmospheric pressure, and this difference enhanc ed as the time of hypoxia treatment increased. Accumulation of chlorop hyll b was inhibited to a higher extent than chlorophyll a. The decrea se in carotenoid pool mainly accounted for the decline in carotene con tent. The content of violaxanthin and lutein + zeaxanthin significantl y decreased only after exposure to hypoxia for 24 h. Hypoxia did not a ffect the content of chlorophylls and carotenoids in the leaves of the seedlings grown under light from the beginning. We conclude that the pigment systems in green and greening etiolated barley seedlings diffe r in their sensitivity to hypobaric hypoxia.