Photosynthesis: Physiological and Ecological Considerations

9.2.3 Leaf angle and leaf movement can control lightabsorption13FIGURE 9.6 Leaf movement in sun-tracking plants.9.2.4 Plants acclimate and adapt to sun and shade14• Acclimation:a process whereby the newly produced leaf has a setof biochemical and morphological characteristics• Adaptation:a process by which an organism becomes fitted to itsenvironment•Sun and shade leaves:(a) Shade leaves have more total chlorophyll perreaction center, have a higher ratio of chlorophyll b tochlorophyll a, and are usually thinner than sun leaves.(b) Sun leaves have more rubisco and a larger pool ofxanthophyll cycle components than shade.(c) shade leaves PSII: PSI = 3:1sun leaves PSII: PSI = 2:17