“…Two seemingly different scenarios exist for modulating the activity of PEPC-PK in C, and CAM leaves. In the former, light activates and darkness inactivates the kinase in vivo (Echevarria et al, 1990;Jiao and Chollet, 1991;Nimmo, 1993). Moreover, treatment of C, leaves with inhibitors of photosynthesis or cytosolic protein synthesis prevents this light activation of PEPC-PK (Jiao et al, 1991a;Bakrim et al, 1992Bakrim et al, , 1993Jiao and Chollet, 1992;Li and Chollet, 1993), implicating the involvement of photosynthesis and protein turnover in the light-signal transduction pathway.…”