ABSTRACT
The physiology and biochemistry of photosynthesis have been the subject of intense investigation for well over 100 years. A range of physiological tools have been developed which have allowed characterization of photosynthetic light-harvesting and electron transport both in vitro and in vivo. The functions of most of the essential components of the electron transport system are well characterized, and their interrelationships are for the most part understood, at least qualitatively. Many of the uncertainties and hypotheses that are currently proving difficult to analyze or test by conventional physiological techniques could be more elegantly resolved using molecular physiology, for example, the presence and role of cyclic electron transport (Scheller, 1996). Although molecular techniques have advanced our understanding of the synthesis, assembly and functional organization of proteins and protein complexes involved in photosynthesis (Andersson and Styring, 1991; Chitnis et al., 1995; Cramer et al., 1996; Hanson and Wydrzynski, 1990) they have made little impact on our understanding of photosynthesis as an integrated, regulated and adaptive physiological process.
