Genetic Control of Leaf Development

Summary Leaf primordia do not differ greatly in shape and size, but mature leaves vary tremendously, largely as a consequence of differential patterns of cell division and expansion. The genetic programs and signaling mechanisms that underlie the development of leaf shape include the sequential and coordinated activities of numerous regulatory genes, themselves positionally regulated by auxin and small RNAs. As the leaf primordium expands, specialized cells in the vascular and epidermal tissues differentiate, relying on intercellular communication for patterning their positions within the tissues.