Distinct Adaptivity During Phosphate Uptake by the CyanobacteriumAnabaena variabilisReflects Information Processing About Preceding Phosphate Supply

Abstract

Abstract Using a phosphate deficient population of the cyanobacterium Anabaena variabilis Kutzing the adaptation of the phosphate uptake system to pulsewise increases in the external phosphate concentration has been studied. The following observations have been made: 1. For an adaptation to occur, the external concentration had to be raised to micromolar levels. No adaptation was observed in the nanomolar concentration range. 2. During adaptation the uptake system was transformed within a few minutes from a more active into a less active state in which uptake behavior obeyed a linear flow-force relationship over a wide concentration range. 3. Novel adaptations were influenced in a distinct way by the outcome of previous adaptations. In consequence, adaptive alterations in kinetic and energetic properties of the phosphate uptake system, revealed during pulsewise increases in the external phosphate concentration, depend on the pattern of previous phosphate fluctuations to which the population had been expos...