[Light-induced reduction of protochlorophyllide in angiosperms and chloroplast development].

One of the final reactions of chlorophyll (Chl) biosynthesis, e.g: photoreduction of protochlorophyllide (Pchlid) to chlorophyllide (Chlid) is a light-induced process in Angiosperm plants and it is catalyzed by light-dependent NADPH-Pchlid oxidoreductase (1.3.1.33; LPOR). In darkness, Chl biosynthesis is stopped at the stage of Pchlid formation. Seedlings and plastids develop according to a different pattern than that observed in the light. Moreover, synthesis of some proteins of the photosynthetic apparatus is inhibited. Light triggers the Pchlid photoreduction to Chlid, which induces the cascade of biochemical reactions and structural changes leading to the assembly of thylakoid membranes. In the present paper, the current knowledge on LPOR protein, mechanism of Pchlid to Chlid photoreduction, the role of lipid structure in etioplasts as well as spectral properties of Pchlid in etiolated seedlings and model systems is summarized.