Pulse Amplitude Modulated Chlorophyll Fluorometry and its Application in Plant Science

Abstract

The development of the pulse amplitude modulation technique to measure chlorophyll a fluorescence has provided an important, widely used tool to investigate various photosynthetic processes in a non-invasive manner. The present chapter is focused on a number of chlorophyll fluorescence parameters that are frequently applied in plant science and can be easily determined in vascular plants. Modes of measurement and details of interpretation of these parameters, as well as examples of applications are described to provide the reader with a comprehensive treatise on the scope of the method of modulation fluorometry. This includes the discussion of still uncertain or speculative explanations, imperfection of current models and problems concerning possible errors in the exact determination of certain parameters. Particular emphasis is put on the effects of stress conditions that directly or indirectly affect the energy conversion in Photosystem II and thus influence fluorescence emission from plant leaves, i.e. are reflected by photochemical and non-photochemical fluorescence quenching phenomena. The chapter also considers the growing use of the fluorescence method including video imaging of fluorescence to identify and study plant mutants.