Photoadaptation and diel periodicity of photosynthesis in the dinoflagellate Prorocentrum mariaelebouriae

Abstract

P. mariae-lebouriae , a dinoflagellate which commonly forms red tides in Chesapeake Bay (USA), is shown to exhibit diel periodicity of photosynthesis and pronounced photoadaptive responses to changes in its photic environment. These 2 physiological characteristics are both manifested as shifts in the photosynthesis-irradiance (P-I) relationship. A new culture methodology is used to separate changes in the P-I curve parameters ( alpha and P sub(max)) that are associated with rhythmicity of photosynthesis from those accompanying light adaptation. This culture approach provides populations of cells that are individually phased to distinct light-dark schedules, allowing periodicity and light adaptation to be studied concurrently. P. mariae-lebouriae shows diel periodicity of photosynthesis comparable to the time-dependent patterns detected for many other phytoplankton of photosynthesis comparable to the time-dependent patterns detected for many other phytoplankton species.