Analysis of Chlorophyll Fluorescence by Means of Noisy Light

Abstract

Linearization is an efficient means of detecting individual components in complex fluorescence induction curves. In a previous investigation based on sine-waves (Hansen, Kolbowski, and Dau, 1987) the components related to the plastoquinone pool, the high-energy state of the thylakoid membrane and the state 1-state 2 transition controller could be identified. In this paper, binary noise is used as an alternative input signal which can also allow linearization by mathematical tools. Comparison with experiments using sine-waves shows that curve-fitting of the noise experiments yields the same data as the sine-wave analysis. Further, some additional components were revealed as labelled by the related time-constants whose values depended on light intensity (e.g. 5, 15, 20, 70, 85, 550 s for spinach at 2.5 W m−2). The advantages of noise analysis are a shorter measuring time and the availability of an on-line criterion which indicates when a sufficient signal-to-noise ratio is reached.