Figure 6.

Expansin-induced primordia develop into normal leaves and lead to reversed phyllotaxy. (A) Expansin-induced leaf. (B) Normally formed leaf. (C) Cross section of the midrib of an expansin-induced leaf. (D) Cross section of the lamina of an expansin-induced leaf. (E and F) Reversal of phyllotaxy after the initiation of a leaf (I′2) (arrow in E) by localized induction of expansin expression. As shown in diagram (F), initially leaves (P3, P2, P1) were formed in an anticlockwise direction. Leaves formed subsequent to I′2 (I′3- I′7) have been formed in a clockwise direction. (G) Side view of plant shown in E to demonstrate leaf insertion points along the stem. e, epidermis; p, palisade; s, spongy mesophyl. (Bar: A and B= 5 mm; C and D = 125 μm.)