Use of a pulse-amplitude modulated chlorophyll fluorometer to study the efficiency of photosynthesis in Arabidopsis plants.

Chlorophyll afluorescence has long been used as a noninvasive means to assess photosynthetic performance in plants. Pulse-amplitude modulated (PAM) fluorometry is one of the most common techniques used to study the induction and quenching of chlorophyll fluorescence in physiological studies. In this chapter, we briefly describe the basics of PAM fluorometry and how to configure the instrument before moving on to some examples of common measurements that can be made using a PAM fluorometer. Photosynthetic performance and energy dissipation are compared between wild type and the npq4-1mutant by examining the maximum photochemical efficiency during high-light stress, the induction and relaxation of non-photochemical quenching, and by plotting light curves.