Figure 9.

Models for the regulation of chloroplast biogenesis and photosynthesis. A, Regulation of photosynthesis by the GNC family. Expression of the GNC family is stimulated by light and cytokinin. The GNC family regulates expression of genes controlling chloroplast biogenesis and stomatal index, both of which contribute to photosynthesis. B, Overlapping and independent roles of the GNC and GLK families in chloroplast biogenesis in the shoot. The thickness of the arrows indicates the relative contribution of each gene family to the development of chloroplasts from the proplastid, to grana expansion, and to chloroplast division.